完全一致

指的是entity与DTO之间参数名、参数类型、参数个数全部相同的情况

entity代码

package com.hxd.simple.domain.entity;

import java.io.Serializable;

import java.time.LocalDateTime;

/**

* @author hxd

*/

public class User implements Serializable {

/**

* 用户id

*/

private Integer id;

/**

* 姓名

*/

private String name;

/**

* 创建时间

*/

private LocalDateTime createTime;

/**

* 序列化id

*/

private static final long serialVersionUID = 1L;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public LocalDateTime getCreateTime() {

return createTime;

}

public void setCreateTime(LocalDateTime createTime) {

this.createTime = createTime;

}

public User() {

}

public User(Integer id, String name, LocalDateTime createTime) {

this.id = id;

this.name = name;

this.createTime = createTime;

}

}

DTO代码

package com.hxd.simple.domain.dto.response;

import java.io.Serializable;

import java.time.LocalDateTime;

/**

* @author hxd

*/

public class UserDTO implements Serializable {

/**

* 用户id

*/

private Integer id;

/**

* 用户名

*/

private String name;

/**

* 创建时间

*/

private LocalDateTime createTime;

/**

* 序列化id

*/

private static final long serialVersionUID = 1L;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public LocalDateTime getCreateTime() {

return createTime;

}

public void setCreateTime(LocalDateTime createTime) {

this.createTime = createTime;

}

public static long getSerialVersionUID() {

return serialVersionUID;

}

}

mapstruct代码

package com.hxd.simple.domain.mapstruct;

import com.hxd.simple.domain.dto.response.UserDTO;

import com.hxd.simple.domain.entity.User;

import org.mapstruct.Mapper;

import java.util.List;

@Mapper(componentModel = "spring")

public interface UserMapStruct {

/**

* 实体类转DTO

* @param user 实体类

* @return DTO对象

*/

UserDTO toResponseDTO(User user);

/**

* 将实体类集合转换成DTO集合

* @param source 实体类集合

* @return DTO集合

*/

List toResponseListDTO(List source);

}

使用mapstruct实现entity转DTO

package com.hxd.simple.controller;

import com.hxd.simple.domain.dto.response.UserDTO;

import com.hxd.simple.domain.entity.User;

import com.hxd.simple.domain.mapstruct.UserMapStruct;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

import java.time.LocalDateTime;

import java.util.ArrayList;

import java.util.List;

@RestController

@RequestMapping("/user")

public class UserController {

@Resource

private UserMapStruct userMapStruct;

@GetMapping("/getUser")

public UserDTO getUser() {

User user = new User();

user.setId(1111);

user.setName("张三");

user.setCreateTime(LocalDateTime.now());

return userMapStruct.toResponseDTO(user);

}

@GetMapping("/getUserList")

public List getUserList() {

List userList = new ArrayList<>();

User user1 = new User(1001, "zs", LocalDateTime.now());

User user2 = new User(1002, "ls", LocalDateTime.now());

User user3 = new User(1003, "ww", LocalDateTime.now());

User user4 = new User(1004, "zl", LocalDateTime.now());

userList.add(user1);

userList.add(user2);

userList.add(user3);

userList.add(user4);

return userMapStruct.toResponseListDTO(userList);

}

}

使用mapstruct实现entity转DTO

package com.hxd.simple.controller;

import com.hxd.simple.domain.dto.response.UserDTO;

import com.hxd.simple.domain.entity.User;

import com.hxd.simple.domain.mapstruct.UserMapStruct;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

import java.time.LocalDateTime;

import java.util.ArrayList;

import java.util.List;

@RestController

@RequestMapping("/user")

public class UserController {

@Resource

private UserMapStruct userMapStruct;

@GetMapping("/getUser")

public UserDTO getUser() {

User user = new User();

user.setId(1111);

user.setName("张三");

user.setCreateTime(LocalDateTime.now());

return userMapStruct.toResponseDTO(user);

}

@GetMapping("/getUserList")

public List getUserList() {

List userList = new ArrayList<>();

User user1 = new User(1001, "zs", LocalDateTime.now());

User user2 = new User(1002, "ls", LocalDateTime.now());

User user3 = new User(1003, "ww", LocalDateTime.now());

User user4 = new User(1004, "zl", LocalDateTime.now());

userList.add(user1);

userList.add(user2);

userList.add(user3);

userList.add(user4);

return userMapStruct.toResponseListDTO(userList);

}

}

总结：

1.entity与DTO完全一致时，mapstruct接口比较简单

2.mapstruct的使用与常规的Spring的bean一样，关键是@Mapper注解的componentModel = "spring"，此注解会在生成的mapstruct接口的实现类上加@Component注解

3.mapstruct生成的class文件如下：

package com.hxd.simple.domain.mapstruct;

import com.hxd.simple.domain.dto.response.UserDTO;

import com.hxd.simple.domain.entity.User;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import org.springframework.stereotype.Component;

@Component

public class UserMapStructImpl implements UserMapStruct {

public UserMapStructImpl() {

}

public UserDTO toResponseDTO(User user) {

if (user == null) {

return null;

} else {

UserDTO userDTO = new UserDTO();

userDTO.setId(user.getId());

userDTO.setName(user.getName());

userDTO.setCreateTime(user.getCreateTime());

return userDTO;

}

}

public List toResponseListDTO(List source) {

if (source == null) {

return null;

} else {

List list = new ArrayList(source.size());

Iterator var3 = source.iterator();

while(var3.hasNext()) {

User user = (User)var3.next();

list.add(this.toResponseDTO(user));

}

return list;

}

}

}

4.要想实现List转List，必须先实现单个entity转DTO