"官方地址：https://projectlombok.org/ GitHub:https://github.com/rzwitserloot/lombok 指导说明文档：http://jnb.ociweb.com/jnb/jnbJan2010.html ======================= ...."

someone1
AI专业者开发社区 1 号成员
AI开发者社区 • 0 回帖 • 1 浏览 • 4 个月前

【lombok】lombok---帮你简化生成必要但臃肿的java代码工具【映射注解和lombok注解同时使用以及映射注解放在属性和get方法上的区别】

官方地址：https://projectlombok.org/

GitHub:https://github.com/rzwitserloot/lombok

指导说明文档：http://jnb.ociweb.com/jnb/jnbJan2010.html

===============================================================================================================

本来来说，lombok 作为一个目前为止【2017-11-27】java 并未将其作为标准来推广。还有很多人问使用它是否合适。

这里不做这种讨论！！！

===============================================================================================================

在使用之前，要明确一点，在开发过程中，一般情况下，仅使用@Data 即可满足生成 entity 类的大部分情况。

摘自指导文档：

Essentially, using @Data on a class is the same as annotating the class with a default @ToString and @EqualsAndHashCode as well as annotating each field with both @Getter and @Setter.

实质上，在一个类上使用 @Data 与用默认的 @ToString 和 @EqualsAndHashCode 注释这个类以及用 @Getter 和 @Setter 注释每个字段是一样的。

===============================================================================================================

使用起来：

一. 安装 lombok 插件【idea 使用为例】

二. 项目引入 lombok 依赖

        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

版本这里不给了，想使用最新版本的，可以自己加上。

三.lombok 注解使用详解

在上面安装插件的时候，可以看到有很多的注解是被支持的：

官方的指导文档，时间久远。所以就找到下面的注解进行详解。

@Getter and @Setter

【属性级别，生成本属性的 get 和 set 方法】

AccessLevel.PROTECTED　　默认生成的方法为 public，此属性可以设置生成方法的访问修饰符【非必须】

转化前：

package com.sxd.entity;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;
public class Order {
@Getter @Setter private String orderId;
@Getter(AccessLevel.PROTECTED) @Setter  private User user;
@Getter @Setter(AccessLevel.NONE) private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public void setOrderId(String orderId)
{
this.orderId = orderId;
}
public String getOrderId()
{
return this.orderId;
}
public void setUser(User user)
{
this.user = user;
}
protected User getUser()
{
return this.user;
}
public String getProductName()
{
return this.productName;
}
}

View Code

=============================================================================

@ToString

【类级别，生成自定义的 toString() 方法】

exclude="｛字段 1，字段 2｝"　　生成的 toString（）不包含哪些字段【非必须】

callSuper=true　　如果继承的有父类的话，可以设置 callSuper 让其调用父类的 toString() 方法【非必须】

转化前：

package com.sxd.entity;
import lombok.ToString;
@ToString(exclude = {"orderId","user"},callSuper = false)
public class Order {
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String orderId;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> User user;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String productName;

}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public String toString()
{
return "Order(productName=" + this.productName + ")";
}
}

View Code

不使用上述属性值的话：

转化前：

package com.sxd.entity;
import lombok.ToString;
@ToString
public class Order {
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String orderId;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> User user;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String productName;

}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public String toString()
{
return "Order(orderId=" + this.orderId + ", user=" + this.user + ", productName=" + this.productName + ")";
}
}

View Code

===================================================================================

@EqualsAndHashCode

【类级别，生成自定义的 equals()方法和 HashCode() 方法】

exclude="｛字段 1，字段 2｝"　　生成的方法不包含哪些字段【非必须】

callSuper=true　　如果继承的有父类的话，可以设置 callSuper 让其调用父类的方法【非必须】

转化前：

package com.sxd.entity;
import lombok.EqualsAndHashCode;
@EqualsAndHashCode(exclude = {"orderId","user"},callSuper = false)
public class Order {
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String orderId;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> User user;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String productName;

}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public int hashCode()
{
int PRIME = 59;int result = 1;Object $productName = this.productName;result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$productName = this.productName;Object other$productName = other.productName;return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
}

View Code

=====================================================================================

@NonNull

【属性级别，验证不能为 null 的注解，如果执行加了这个注解的 setter 方法时设置为 Null，抛异常 java.lang.NullPointerException】

转化前：

package com.sxd.entity;
import lombok.Getter;
import lombok.NonNull;
import lombok.Setter;
public class Order {
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String orderId;
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> User user;
@NonNull @Getter @Setter </span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String productName;

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Order() {

}

}

View Code

编译后：

package com.sxd.entity;
import lombok.NonNull;
public class Order
{
private String orderId;
private User user;
@NonNull
private String productName;
public void setProductName(@NonNull String productName)
{
if (productName == null) {
throw new NullPointerException("productName");
}
this.productName = productName;
}
@NonNull
public String getProductName()
{
return this.productName;
}
}

View Code

如果去执行 setter 方法并赋值 Null, 则报错：

注意报错行数：

===========================================================================================

@NoArgsConstructor

【类级别，生成无参构造方法】

　focus=true　　当类中有 final 字段没有被初始化时，编译器会报错，此时可用 @NoArgsConstructor(force = true)，然后就会为没有初始化的 final 字段设置默认值 0 / false / null。对于具有约束的字段（例如 @NonNull 字段），不会生成检查或分配，因此请注意，正确初始化这些字段之前，这些约束无效。
转化前：

package com.sxd.entity;
import lombok.NoArgsConstructor;
@NoArgsConstructor(force = true)
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
}

View Code

=====================================================================================

@RequiredArgsConstructor

【类级别，生成有或无参的静态方法，用于获取本对象】

staticName = "自定义静态方法名"

转化前：

package com.sxd.entity;
import lombok.RequiredArgsConstructor;
@RequiredArgsConstructor(staticName = "build")
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

转化后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public static Order build()
{
return new Order();
}
}

View Code

===============================================================================

@AllArgsConstructor

【类级别，生成全参构造方法】

转化前：

package com.sxd.entity;
import lombok.AllArgsConstructor;
@AllArgsConstructor
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
import java.beans.ConstructorProperties;
public class Order
{
private String orderId;
private User user;
private String productName;
@ConstructorProperties({"orderId", "user", "productName"})
public Order(String orderId, User user, String productName)
{
this.orderId = orderId;this.user = user;this.productName = productName;
}
}

View Code

================================================================================

@Data

【类级别，此注解为 lombok 中最常用注解】

【@Data 包含了 @ToString，@EqualsAndHashCode，@Getter / @Setter 和 @RequiredArgsConstructor 的功能】

staticConstructor="静态实例化方法名"

转化前：

package com.sxd.entity;
import lombok.Data;
@Data(staticConstructor = "build")
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public static Order build()
{
return new Order();
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $orderId = getOrderId();result = result * 59 + ($orderId == null ? 43 : $orderId.hashCode());Object $user = getUser();result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $productName = getProductName();result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$orderId = getOrderId();Object other$orderId = other.getOrderId();
if (this$orderId == null ? other$orderId != null : !this$orderId.equals(other$orderId)) {
return false;
}
Object this$user = getUser();Object other$user = other.getUser();
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$productName = getProductName();Object other$productName = other.getProductName();return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
public void setOrderId(String orderId)
{
this.orderId = orderId;
}
public void setUser(User user)
{
this.user = user;
}
public void setProductName(String productName)
{
this.productName = productName;
}
public String toString()
{
return "Order(orderId=" + getOrderId() + ", user=" + getUser()+ ", productName=" + getProductName() + ")";
}
public String getOrderId()
{
return this.orderId;
}
public User getUser()
{
return this.user;
}
public String getProductName()
{
return this.productName;
}
}

View Code

@Accessors

【类级别，控制 get、set 方法】

fluent　　 boolean 值，默认为 false。此字段主要为控制生成的 getter 和 setter 方法前面是否带 get/set；false 带，true 不带
chain 　　boolean 值，默认 false。如果设置为 true，setter 返回的是此对象，方便链式调用方法
prefix 　　设置前缀例如：@Accessors(prefix = "abc") private String abcAge 当生成 get/set 方法时，会把此前缀去掉

转化前：【注意三个属性设值以及生成】

package com.sxd.entity;
import lombok.Data;
import lombok.experimental.Accessors;
@Data
@Accessors(fluent = false,chain = false,prefix = "aaa")
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public String toString()
{
return "Order(orderId=" + this.orderId + ", user=" + this.user + ", productName=" + this.productName + ")";
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $orderId = this.orderId;result = result * 59 + ($orderId == null ? 43 : $orderId.hashCode());Object $user = this.user;result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $productName = this.productName;result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$orderId = this.orderId;Object other$orderId = other.orderId;
if (this$orderId == null ? other$orderId != null : !this$orderId.equals(other$orderId)) {
return false;
}
Object this$user = this.user;Object other$user = other.user;
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$productName = this.productName;Object other$productName = other.productName;return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
}

View Code

===========================================================

转化前：【注意 fluent】

package com.sxd.entity;
import lombok.Data;
import lombok.experimental.Accessors;
@Data
@Accessors(fluent = true,chain = false)
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public void productName(String productName)
{
this.productName = productName;
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $orderId = orderId();result = result * 59 + ($orderId == null ? 43 : $orderId.hashCode());Object $user = user();result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $productName = productName();result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public void orderId(String orderId)
{
this.orderId = orderId;
}
public void user(User user)
{
this.user = user;
}
public String toString()
{
return "Order(orderId=" + orderId() + ", user=" + user()+ ", productName=" + productName() + ")";
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$orderId = orderId();Object other$orderId = other.orderId();
if (this$orderId == null ? other$orderId != null : !this$orderId.equals(other$orderId)) {
return false;
}
Object this$user = user();Object other$user = other.user();
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$productName = productName();Object other$productName = other.productName();return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
public String orderId()
{
return this.orderId;
}
public User user()
{
return this.user;
}
public String productName()
{
return this.productName;
}
}

View Code

==============================================================================

转化前：【注意 chain】

package com.sxd.entity;
import lombok.Data;
import lombok.experimental.Accessors;
@Data
@Accessors(fluent = false,chain = true)
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public Order setProductName(String productName)
{
this.productName = productName;return this;
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $orderId = getOrderId();result = result * 59 + ($orderId == null ? 43 : $orderId.hashCode());Object $user = getUser();result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $productName = getProductName();result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public Order setOrderId(String orderId)
{
this.orderId = orderId;return this;
}
public Order setUser(User user)
{
this.user = user;return this;
}
public String toString()
{
return "Order(orderId=" + getOrderId() + ", user=" + getUser()+ ", productName=" + getProductName() + ")";
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$orderId = getOrderId();Object other$orderId = other.getOrderId();
if (this$orderId == null ? other$orderId != null : !this$orderId.equals(other$orderId)) {
return false;
}
Object this$user = getUser();Object other$user = other.getUser();
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$productName = getProductName();Object other$productName = other.getProductName();return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
public String getOrderId()
{
return this.orderId;
}
public User getUser()
{
return this.user;
}
public String getProductName()
{
return this.productName;
}
}

View Code

===================================================================

转化前：【注意 prefix】

package com.sxd.entity;
import lombok.Data;
import lombok.experimental.Accessors;
@Data
@Accessors(fluent = false,chain = true,prefix = "product")
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
public class Order
{
private String orderId;
private User user;
private String productName;
public String toString()
{
return "Order(orderId=" + this.orderId + ", user=" + this.user + ", productName=" + getName()+ ")";
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $orderId = this.orderId;result = result * 59 + ($orderId == null ? 43 : $orderId.hashCode());Object $user = this.user;result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $productName = getName();result = result * 59 + ($productName == null ? 43 : $productName.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof Order;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Order)) {
return false;
}
Order other = (Order)o;
if (!other.canEqual(this)) {
return false;
}
Object this$orderId = this.orderId;Object other$orderId = other.orderId;
if (this$orderId == null ? other$orderId != null : !this$orderId.equals(other$orderId)) {
return false;
}
Object this$user = this.user;Object other$user = other.user;
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$productName = getName();Object other$productName = other.getName();return this$productName == null ? other$productName == null : this$productName.equals(other$productName);
}
public Order setName(String productName)
{
this.productName = productName;return this;
}
public String getName()
{
return this.productName;
}
}

View Code

=========================================================================

@Cleanup

【代码级别，清理资源 / 关闭资源注解】

转化前：

public void testCleanUp() {
    try {
        @Cleanup ByteArrayOutputStream baos = new ByteArrayOutputStream();
        baos.write(new byte[] {'Y','e','s'});
        System.out.println(baos.toString());
    } catch (IOException e) {e.printStackTrace();
    }
}

View Code

编译后：

public void testCleanUp() {
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            baos.write(new byte[]{'Y', 'e', 's'});
            System.out.println(baos.toString());
        } finally {baos.close();
        }
    } catch (IOException e) {e.printStackTrace();
    }
}

View Code

=========================================================================

@Synchronized

【方法级别，同步 / 线程安全注解】

转化前：

private DateFormat format = new SimpleDateFormat("MM-dd-YYYY");
@Synchronized
public String synchronizedFormat(Date date) {
return format.format(date);
}

View Code

编译后：

private final java.lang.Object $lock = new java.lang.Object[0];
private DateFormat format = new SimpleDateFormat("MM-dd-YYYY");
public String synchronizedFormat(Date date) {
synchronized ($lock) {
return format.format(date);
}
}

View Code

=========================================================================

@Wither

【属性级别，提供了给 final 字段赋值的一种方法】

转化前：

import lombok.AccessLevel;
import lombok.NonNull;
import lombok.experimental.Wither;
public class WitherExample {
@Wither private final int age;
@Wither(AccessLevel.PROTECTED) @NonNull private final String name;
public WitherExample(String name, int age) {
if (name == null) throw new NullPointerException();
this.name = name;
this.age = age;
}
}

View Code

编译后：

import lombok.NonNull;
public class WitherExample {
private final int age;
private @NonNull final String name;
public WitherExample(String name, int age) {
if (name == null) throw new NullPointerException();
this.name = name;
this.age = age;
}
public WitherExample withAge(int age) {
return this.age == age ? this : new WitherExample(age, name);
}
protected WitherExample withName(@NonNull String name) {
if (name == null) throw new java.lang.NullPointerException("name");
return this.name == name ? this : new WitherExample(age, name);
}
}

View Code

==================================================================================

@Builder

【类级别，为你的类生成复杂的构建器 API】

转化前：

package com.sxd.entity;
import lombok.Builder;
@Builder
public class Order {
private String orderId;
private User user;
private String productName;
}

View Code

编译后：

package com.sxd.entity;
import java.beans.ConstructorProperties;
public class Order
{
private String orderId;
private User user;
private String productName;
public static class OrderBuilder
{
private String orderId;
private User user;
private String productName;
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String toString()
{
  </span><span style="color: rgba(0, 0, 255, 1)">return</span> "Order.OrderBuilder(orderId=" + <span style="color: rgba(0, 0, 255, 1)">this</span>.orderId + ", user=" + <span style="color: rgba(0, 0, 255, 1)">this</span>.user + ", productName=" + <span style="color: rgba(0, 0, 255, 1)">this</span>.productName + ")"<span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Order build()
{
  </span><span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">new</span> Order(<span style="color: rgba(0, 0, 255, 1)">this</span>.orderId, <span style="color: rgba(0, 0, 255, 1)">this</span>.user, <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">.productName);
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> OrderBuilder productName(String productName)
{
  </span><span style="color: rgba(0, 0, 255, 1)">this</span>.productName = productName;<span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> OrderBuilder user(User user)
{
  </span><span style="color: rgba(0, 0, 255, 1)">this</span>.user = user;<span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> OrderBuilder orderId(String orderId)
{
  </span><span style="color: rgba(0, 0, 255, 1)">this</span>.orderId = orderId;<span style="color: rgba(0, 0, 255, 1)">return</span> <span style="color: rgba(0, 0, 255, 1)">this</span><span style="color: rgba(0, 0, 0, 1)">;
}

}
public static OrderBuilder builder()
{
return new OrderBuilder();
}
@ConstructorProperties({"orderId", "user", "productName"})
Order(String orderId, User user, String productName)
{
this.orderId = orderId;this.user = user;this.productName = productName;
}
}

View Code

==============================================================

@Delegate

【属性级别，同化所在属性的类型的方法到本类中】

转化前：【本属性类型为 String】

package com.sxd.entity;
import lombok.experimental.Delegate;
public class Order {
private String orderId;
private User user;
@Delegate private String productName;
}

View Code

编译后：

package com.sxd.entity;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.Locale;
import java.util.stream.IntStream;
public class Order
{
private String orderId;
private User user;
private String productName;
public IntStream codePoints()
{
return this.productName.codePoints();
}
public IntStream chars()
{
return this.productName.chars();
}
public String intern()
{
return this.productName.intern();
}
public char[] toCharArray()
{
return this.productName.toCharArray();
}
public String trim()
{
return this.productName.trim();
}
public String toUpperCase()
{
return this.productName.toUpperCase();
}
public String toUpperCase(Locale arg0)
{
return this.productName.toUpperCase(arg0);
}
public String toLowerCase()
{
return this.productName.toLowerCase();
}
public String toLowerCase(Locale arg0)
{
return this.productName.toLowerCase(arg0);
}
public String[] split(String arg0)
{
return this.productName.split(arg0);
}
public String[] split(String arg0, int arg1)
{
return this.productName.split(arg0, arg1);
}
public String replace(CharSequence arg0, CharSequence arg1)
{
return this.productName.replace(arg0, arg1);
}
public String replaceAll(String arg0, String arg1)
{
return this.productName.replaceAll(arg0, arg1);
}
public String replaceFirst(String arg0, String arg1)
{
return this.productName.replaceFirst(arg0, arg1);
}
public boolean contains(CharSequence arg0)
{
return this.productName.contains(arg0);
}
public boolean matches(String arg0)
{
return this.productName.matches(arg0);
}
public String replace(char arg0, char arg1)
{
return this.productName.replace(arg0, arg1);
}
public String concat(String arg0)
{
return this.productName.concat(arg0);
}
public CharSequence subSequence(int arg0, int arg1)
{
return this.productName.subSequence(arg0, arg1);
}
public String substring(int arg0, int arg1)
{
return this.productName.substring(arg0, arg1);
}
public String substring(int arg0)
{
return this.productName.substring(arg0);
}
public int lastIndexOf(String arg0, int arg1)
{
return this.productName.lastIndexOf(arg0, arg1);
}
public int lastIndexOf(String arg0)
{
return this.productName.lastIndexOf(arg0);
}
public int indexOf(String arg0, int arg1)
{
return this.productName.indexOf(arg0, arg1);
}
public int indexOf(String arg0)
{
return this.productName.indexOf(arg0);
}
public int lastIndexOf(int arg0, int arg1)
{
return this.productName.lastIndexOf(arg0, arg1);
}
public int lastIndexOf(int arg0)
{
return this.productName.lastIndexOf(arg0);
}
public int indexOf(int arg0, int arg1)
{
return this.productName.indexOf(arg0, arg1);
}
public int indexOf(int arg0)
{
return this.productName.indexOf(arg0);
}
public boolean endsWith(String arg0)
{
return this.productName.endsWith(arg0);
}
public boolean startsWith(String arg0)
{
return this.productName.startsWith(arg0);
}
public boolean startsWith(String arg0, int arg1)
{
return this.productName.startsWith(arg0, arg1);
}
public boolean regionMatches(boolean arg0, int arg1, String arg2, int arg3, int arg4)
{
return this.productName.regionMatches(arg0, arg1, arg2, arg3, arg4);
}
public boolean regionMatches(int arg0, String arg1, int arg2, int arg3)
{
return this.productName.regionMatches(arg0, arg1, arg2, arg3);
}
public int compareToIgnoreCase(String arg0)
{
return this.productName.compareToIgnoreCase(arg0);
}
public int compareTo(String arg0)
{
return this.productName.compareTo(arg0);
}
public boolean equalsIgnoreCase(String arg0)
{
return this.productName.equalsIgnoreCase(arg0);
}
public boolean contentEquals(CharSequence arg0)
{
return this.productName.contentEquals(arg0);
}
public boolean contentEquals(StringBuffer arg0)
{
return this.productName.contentEquals(arg0);
}
public byte[] getBytes()
{
return this.productName.getBytes();
}
public byte[] getBytes(Charset arg0)
{
return this.productName.getBytes(arg0);
}
public byte[] getBytes(String arg0)
throws UnsupportedEncodingException
{
return this.productName.getBytes(arg0);
}
@Deprecated
public void getBytes(int arg0, int arg1, byte[] arg2, int arg3)
{
this.productName.getBytes(arg0, arg1, arg2, arg3);
}
public void getChars(int arg0, int arg1, char[] arg2, int arg3)
{
this.productName.getChars(arg0, arg1, arg2, arg3);
}
public int offsetByCodePoints(int arg0, int arg1)
{
return this.productName.offsetByCodePoints(arg0, arg1);
}
public int codePointCount(int arg0, int arg1)
{
return this.productName.codePointCount(arg0, arg1);
}
public int codePointBefore(int arg0)
{
return this.productName.codePointBefore(arg0);
}
public int codePointAt(int arg0)
{
return this.productName.codePointAt(arg0);
}
public char charAt(int arg0)
{
return this.productName.charAt(arg0);
}
public boolean isEmpty()
{
return this.productName.isEmpty();
}
public int length()
{
return this.productName.length();
}
}

View Code

==========================================================================

转化前：【所在属性类型为 List】

package com.sxd.entity;
import lombok.experimental.Delegate;
import java.util.List;
public class Order {
private String orderId;
private User user;
private String productName;
@Delegate  private List<Integer> arrList;
}

View Code

编译后：

package com.sxd.entity;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Spliterator;
import java.util.function.UnaryOperator;
public class Order
{
private String orderId;
private User user;
private String productName;
private List<Integer> arrList;
public Spliterator<Integer> spliterator()
{
return this.arrList.spliterator();
}
public List<Integer> subList(int arg0, int arg1)
{
return this.arrList.subList(arg0, arg1);
}
public ListIterator<Integer> listIterator(int arg0)
{
return this.arrList.listIterator(arg0);
}
public ListIterator<Integer> listIterator()
{
return this.arrList.listIterator();
}
public int lastIndexOf(Object arg0)
{
return this.arrList.lastIndexOf(arg0);
}
public int indexOf(Object arg0)
{
return this.arrList.indexOf(arg0);
}
public Integer remove(int arg0)
{
return (Integer)this.arrList.remove(arg0);
}
public void add(int arg0, Integer arg1)
{
this.arrList.add(arg0, arg1);
}
public Integer set(int arg0, Integer arg1)
{
return (Integer)this.arrList.set(arg0, arg1);
}
public Integer get(int arg0)
{
return (Integer)this.arrList.get(arg0);
}
public void clear()
{
this.arrList.clear();
}
public void sort(Comparator<? super Integer> arg0)
{
this.arrList.sort(arg0);
}
public void replaceAll(UnaryOperator<Integer> arg0)
{
this.arrList.replaceAll(arg0);
}
public boolean retainAll(Collection<?> arg0)
{
return this.arrList.retainAll(arg0);
}
public boolean removeAll(Collection<?> arg0)
{
return this.arrList.removeAll(arg0);
}
public boolean addAll(int arg0, Collection<? extends Integer> arg1)
{
return this.arrList.addAll(arg0, arg1);
}
public boolean addAll(Collection<? extends Integer> arg0)
{
return this.arrList.addAll(arg0);
}
public boolean containsAll(Collection<?> arg0)
{
return this.arrList.containsAll(arg0);
}
public boolean remove(Object arg0)
{
return this.arrList.remove(arg0);
}
public boolean add(Integer arg0)
{
return this.arrList.add(arg0);
}
public <T> T[] toArray(T[] arg0)
{
return this.arrList.toArray(arg0);
}
public Object[] toArray()
{
return this.arrList.toArray();
}
public Iterator<Integer> iterator()
{
return this.arrList.iterator();
}
public boolean contains(Object arg0)
{
return this.arrList.contains(arg0);
}
public boolean isEmpty()
{
return this.arrList.isEmpty();
}
public int size()
{
return this.arrList.size();
}
}

View Code

============================================================================

@SneakyThrows

【异常处理注解，这里不做详细解释】

转化前：

@SneakyThrows
public void testSneakyThrows() {
    throw new IllegalAccessException();}

View Code

编译后：

public void testSneakyThrows() {
    try {
        throw new IllegalAccessException();} catch (java.lang.Throwable $ex) {
        throw lombok.Lombok.sneakyThrow($ex);
    }
}

View Code

============================================================================

@_({注解 1，注解 2}) 或 @_(注解) 配合 onMethod= 使用

【属性级别，用于将注解放在注解中使用】

转化前：

package com.sxd.entity;
import lombok.Getter;
import lombok.Setter;
import javax.persistence.Column;
import javax.persistence.Id;
public class Order {
@Getter(onMethod </span>=<span style="color: rgba(0, 0, 0, 1)"> @_({@Column,@Id}))
@Setter
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String id;

}

View Code

编译后：

package com.sxd.entity;
import javax.persistence.Column;
import javax.persistence.Id;
public class Order
{
private String id;
@Column
@Id
public String getId()
{
return this.id;
}
public void setId(String id)
{
this.id = id;
}
}

View Code

【注意：这个时而有用，时而报错，具体问题依旧找不到 ~~~~~~~~~~~~ 具体看附录 2】

============================================================================================================

最后，如果使用了 lombok 的话，如何在实体类上声明实体对数据表的映射？

注意：@Column 等注解是可以直接放在字段上而不用放在 get 方法上

例如：创建不同包下同名的实体类 User.java

自己写 get/set 方法的 User 类如下：

package com.sxd.entity;
import org.hibernate.annotations.GenericGenerator;
import javax.persistence.*;
@Entity
@GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator" )
public class User {
private String id;
private String username;
private String password;
private Integer age;
@Id
@GeneratedValue(generator </span>= "uuid2"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getId() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> id;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setId(String id) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.id =<span style="color: rgba(0, 0, 0, 1)"> id;
}

@Column(nullable </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getUsername() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> username;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setUsername(String username) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.username =<span style="color: rgba(0, 0, 0, 1)"> username;
}

@Column(nullable </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getPassword() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> password;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setPassword(String password) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.password =<span style="color: rgba(0, 0, 0, 1)"> password;
}

@Column(nullable </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> Integer getAge() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> age;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setAge(Integer age) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.age =<span style="color: rgba(0, 0, 0, 1)"> age;
}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> User() {

}

</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> User(String id, String username, String password, Integer age) {
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.id =<span style="color: rgba(0, 0, 0, 1)"> id;
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.username =<span style="color: rgba(0, 0, 0, 1)"> username;
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.password =<span style="color: rgba(0, 0, 0, 1)"> password;
    </span><span style="color: rgba(0, 0, 255, 1)">this</span>.age =<span style="color: rgba(0, 0, 0, 1)"> age;
}

@Override
</span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String toString() {
    </span><span style="color: rgba(0, 0, 255, 1)">return</span> "User{" +
            "id='" + id + '\'' +
            ", username='" + username + '\'' +
            ", password='" + password + '\'' +
            ", age=" + age +
            '}'<span style="color: rgba(0, 0, 0, 1)">;
}

}

View Code

编译完是：

package com.sxd.entity;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import org.hibernate.annotations.GenericGenerator;
@Entity
@GenericGenerator(name="uuid2", strategy="org.hibernate.id.UUIDGenerator")
public class User
{
private String id;
private String username;
private String password;
private Integer age;
@Id
@GeneratedValue(generator="uuid2")
public String getId()
{
return this.id;
}
public void setId(String id)
{
this.id = id;
}
@Column(nullable=false)
public String getUsername()
{
return this.username;
}
public void setUsername(String username)
{
this.username = username;
}
@Column(nullable=false)
public String getPassword()
{
return this.password;
}
public void setPassword(String password)
{
this.password = password;
}
@Column(nullable=false)
public Integer getAge()
{
return this.age;
}
public void setAge(Integer age)
{
this.age = age;
}
public User(){}
public User(String id, String username, String password, Integer age)
{
this.id = id;
this.username = username;
this.password = password;
this.age = age;
}
public String toString()
{
return "User{id='" + this.id + ''' + ", username='" + this.username + ''' + ", password='" + this.password + ''' + ", age=" + this.age + '}';
}
}

View Code

===================　　　　　　　　　　　　　　　　　　　　　==================================

使用 lombok 之后如下：

package com.sxd.controller;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;
import org.hibernate.annotations.GenericGenerator;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
@Entity
@GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator" )
@Data(staticConstructor = "of")
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class User {
@Id
@GeneratedValue(generator = "uuid2")private String id;
private String username;
@Column(nullable </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String password;

@Column(nullable </span>= <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer age;

}

View Code

编译完是：

package com.sxd.controller;
import java.beans.ConstructorProperties;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import org.hibernate.annotations.GenericGenerator;
@Entity
@GenericGenerator(name="uuid2", strategy="org.hibernate.id.UUIDGenerator")
public class User
{
@Id
@GeneratedValue(generator="uuid2")
private String id;
private String username;
@Column(nullable=false)
private String password;
@Column(nullable=false)
private Integer age;
public User setAge(Integer age)
{
this.age = age;return this;
}
public String toString()
{
return "User(id=" + getId() + ", username=" + getUsername()+ ", password=" + getPassword() + ", age=" + getAge()+ ")";
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $id = getId();result = result * 59 + ($id == null ? 43 : $id.hashCode());Object $username = getUsername();result = result * 59 + ($username == null ? 43 : $username.hashCode());Object $password = getPassword();result = result * 59 + ($password == null ? 43 : $password.hashCode());Object $age = getAge();result = result * 59 + ($age == null ? 43 : $age.hashCode());return result;
}
protected boolean canEqual(Object other)
{
return other instanceof User;
}
public User setId(String id)
{
this.id = id;return this;
}
public User setUsername(String username)
{
this.username = username;return this;
}
public User setPassword(String password)
{
this.password = password;return this;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof User)) {
return false;
}
User other = (User)o;
if (!other.canEqual(this)) {
return false;
}
Object this$id = getId();Object other$id = other.getId();
if (this$id == null ? other$id != null : !this$id.equals(other$id)) {
return false;
}
Object this$username = getUsername();Object other$username = other.getUsername();
if (this$username == null ? other$username != null : !this$username.equals(other$username)) {
return false;
}
Object this$password = getPassword();Object other$password = other.getPassword();
if (this$password == null ? other$password != null : !this$password.equals(other$password)) {
return false;
}
Object this$age = getAge();Object other$age = other.getAge();return this$age == null ? other$age == null : this$age.equals(other$age);
}
@ConstructorProperties({"id", "username", "password", "age"})
public User(String id, String username, String password, Integer age)
{
this.id = id;this.username = username;this.password = password;this.age = age;
}
public String getId()
{
return this.id;
}
public String getUsername()
{
return this.username;
}
public String getPassword()
{
return this.password;
}
public Integer getAge()
{
return this.age;
}
public User(){}
}

View Code

有一个疑问，映射注解放在属性上和放在 get 方法上有什么区别？？？【看附录 3】

=============================================================== 附录 1：equals()方法和 hashCode() 方法的意义 ==========================================================

摘录：

1.hashcode 是用来查找的，如果你学过数据结构就应该知道，在查找和排序这一章有  
例如内存中有这样的位置  
0  1  2  3  4  5  6  7    
而我有个类，这个类有个字段叫 ID, 我要把这个类存放在以上 8 个位置之一，如果不用 hashcode 而任意存放，那么当查找时就需要到这八个位置里挨个去找，或者用二分法一类的算法。  
但如果用 hashcode 那就会使效率提高很多。  
我们这个类中有个字段叫 ID, 那么我们就定义我们的 hashcode 为 ID％8，然后把我们的类存放在取得得余数那个位置。比如我们的 ID 为 9，9 除 8 的余数为 1，那么我们就把该类存在 1 这个位置，如果 ID 是 13，求得的余数是 5，那么我们就把该类放在 5 这个位置。这样，以后在查找该类时就可以通过 ID 除 8 求余数直接找到存放的位置了。  
2. 但是如果两个类有相同的 hashcode 怎么办那（我们假设上面的类的 ID 不是唯一的），例如 9 除以 8 和 17 除以 8 的余数都是 1，那么这是不是合法的，
回答是：可以这样。那么如何判断呢？在这个时候就需要定义 equals 了。
也就是说，我们先通过 hashcode 来判断两个类是否存放某个桶里，但这个桶里可能有很多类，那么我们就需要再通过 equals 来在这个桶里找到我们要的类。
那么。重写了 equals()，为什么还要重写 hashCode() 呢？
想想，你要在一个桶里找东西，你必须先要找到这个桶啊，你不通过重写 hashcode()来找到桶，光重写 equals() 有什么用啊

============================================================== 附录 2：@Getter() 等 lombok 注解配合 hibernate 的映射注解怎么使用 ===========================================================

如果在项目中真的使用 lombok 的注解的话，映射注解应该如何处理呢？

寥寥无几的资料中有大概类似于如下的写法：

　　@Getter(onMethod = @_({@Id,@Column(name="id",nullable=false),@GeneratedValue(strategy= GenerationType.AUTO)}))
    @Setter
    private Integer id;

亲自试了一下，

如下：

报错如下：

其实在 @Getter() 注解接口中定义如下：

但是具体怎么去写，还没有研究出来。

【如有解决方法，不吝赐教！！】

所以，最终按照并列将注解写在属性上，而不是在 @Getter（）注解中写 @Column（）注解。

如下：

@Data(staticConstructor = "of")
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
@Entity
@GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator" )
public class Member {
@Id
@GeneratedValue(generator </span>= "uuid2"<span style="color: rgba(0, 0, 0, 1)">)
@Column(name </span>= "memberId"<span style="color: rgba(0, 0, 0, 1)">)
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String memberId;

@OneToOne(cascade </span>= {CascadeType.MERGE,CascadeType.REFRESH},fetch =<span style="color: rgba(0, 0, 0, 1)"> FetchType.EAGER)
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> User user;

@Column(name</span>="memberGrade",nullable = <span style="color: rgba(0, 0, 255, 1)">false</span><span style="color: rgba(0, 0, 0, 1)">)
@NonNull
</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> Integer memberGrade;

}

View Code

编译完成如下：

package com.sxd.entity;
import java.beans.ConstructorProperties;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import lombok.NonNull;
import org.hibernate.annotations.GenericGenerator;
@Entity
@GenericGenerator(name="uuid2", strategy="org.hibernate.id.UUIDGenerator")
public class Member
{
@Id
@GeneratedValue(generator="uuid2")
@Column(name="memberId")
private String memberId;
@OneToOne(cascade={javax.persistence.CascadeType.MERGE, javax.persistence.CascadeType.REFRESH}, fetch=FetchType.EAGER)
private User user;
@Column(name="memberGrade", nullable=false)
@NonNull
private Integer memberGrade;
public String toString()
{
return "Member(memberId=" + getMemberId() + ", user=" + getUser()+ ", memberGrade=" + getMemberGrade() + ")";
}
public int hashCode()
{
int PRIME = 59;int result = 1;Object $memberId = getMemberId();result = result * 59 + ($memberId == null ? 43 : $memberId.hashCode());Object $user = getUser();result = result * 59 + ($user == null ? 43 : $user.hashCode());Object $memberGrade = getMemberGrade();result = result * 59 + ($memberGrade == null ? 43 : $memberGrade.hashCode());return result;
}
public Member setMemberId(String memberId)
{
this.memberId = memberId;return this;
}
public Member setUser(User user)
{
this.user = user;return this;
}
public Member setMemberGrade(@NonNull Integer memberGrade)
{
if (memberGrade == null) {
throw new NullPointerException("memberGrade");
}
this.memberGrade = memberGrade;return this;
}
protected boolean canEqual(Object other)
{
return other instanceof Member;
}
public boolean equals(Object o)
{
if (o == this) {
return true;
}
if (!(o instanceof Member)) {
return false;
}
Member other = (Member)o;
if (!other.canEqual(this)) {
return false;
}
Object this$memberId = getMemberId();Object other$memberId = other.getMemberId();
if (this$memberId == null ? other$memberId != null : !this$memberId.equals(other$memberId)) {
return false;
}
Object this$user = getUser();Object other$user = other.getUser();
if (this$user == null ? other$user != null : !this$user.equals(other$user)) {
return false;
}
Object this$memberGrade = getMemberGrade();Object other$memberGrade = other.getMemberGrade();return this$memberGrade == null ? other$memberGrade == null : this$memberGrade.equals(other$memberGrade);
}
@ConstructorProperties({"memberId", "user", "memberGrade"})
public Member(String memberId, User user, @NonNull Integer memberGrade)
{
if (memberGrade == null) {
throw new NullPointerException("memberGrade");
}
this.memberId = memberId;this.user = user;this.memberGrade = memberGrade;
}
public String getMemberId()
{
return this.memberId;
}
public User getUser()
{
return this.user;
}
@NonNull
public Integer getMemberGrade()
{
return this.memberGrade;
}
public Member(){}
}

View Code

那么最后看附录 3，了解最后一个问题，映射注解放在属性上和放在 get 方法上有什么区别？

======================================================================= 附录 3：映射注解放在属性上和放在 get() 方法上有什么区别 ======================================================================

摘录自：http://blog.csdn.net/most_rabbitfishes/article/details/70904949

对于属性字段和表的字段关系对应的注解属性的位置，一般我们采用以下两种方式:

第一种：

是把注解 @Column(name ="xx") 放在 field 上，一种是把注解放在 get 方法上一般放在 field 上看起来比较集中、清晰；

第二种：

是把注解 @Column(name= "xx") 放在 get 方法上，这种方式看起来比较散漫、不很清楚；

但是第一种方式这样做实际上破坏了 java 面向对象的封装性，原因是一般我们写 javaBean，成员变量通常定义为 private，目的就是不让别人来直接访问的私有属性，而我们把注解放在私有成员的变量上，就是默认 hibernate 可以直接访问我们的私有的成员变量，所以我们定义属性为 private，就实际没有多大意义，至于 hibernate 为什么能访问，hibernate 采用 java 的反射机制完全可以访问私有成员变量！所以应该放在 get 方法上，第二种方式这个时候就显得更加合理。

随即，我采用了附录 2 中实体用于 hibernate 自动生成数据表的表结构：

Hibernate 自动帮我们建表:

如果我们采用注解的方式在我们的实体 Bean 上，又想通过扫描这些注解的 Bean，通过 Hibernate 自动帮我们建表，那么你就会发现字段注解的位置不同甚至会影响到建表的结构，尤其是大字段、外键约束的生成效果。

如果采用第一种方式注解到私有字段上，这种帮我们建立表结构、约束条件和大字段 Lob 类型这些都是非常正常的，而通过第二种方式注解到 get 方法上，这种帮我们的建立的表大部分正常字段正常，而外键关联的和大字段就会出现问题.

虽然项目的开发我们不采用 hibernate 帮我们自动建表，通常我们还是要手动的建表，所以这一些是对于通过 Hibernate 帮我们自动建表要考虑的！而实际开发中，已注解在 get 方法上为多数！

结论：如上将注解建立在属性上，生成的表结构，约束条件，外键等都正常，所以，如果你要使用 hibernate 的生成策略，在你建立好实体之后自动去建立数据表的话，同时使用 lombok 的注解和映射注解都放在属性上是合适的！！！

【lombok】lombok---帮你简化生成必要但臃肿的java代码工具【映射注解和lombok注解同时使用以及映射注解放在属性和get方法上的区别】

@Getter and @Setter

=============================================================================

@ToString

===================================================================================

@EqualsAndHashCode

=====================================================================================

@NonNull

===========================================================================================

@NoArgsConstructor

=====================================================================================

@RequiredArgsConstructor

===============================================================================

@AllArgsConstructor

================================================================================

@Data

@Accessors

=========================================================================

@Cleanup

=========================================================================

@Synchronized

=========================================================================

@Wither

==================================================================================

@Builder

==============================================================

@Delegate

============================================================================

@SneakyThrows

============================================================================

@_({注解 1，注解 2}) 或 @_(注解) 配合 onMethod= 使用

相关帖子

随便看看