Java对象之间的属性赋值
对象之间的属性赋值
主要通过org.springframework.beans.BeanUtils.copyProperties方法进行对象之间的属性赋值。
赋值前提 -- 两个对象要赋值的属性名需要保持一致
对象赋值
# 将source对象赋值给target对象
BeanUtils.copyProperties(source, target);
List之间的对象赋值
/**
* @param input 输入集合
* @param clazz 输出集合类型
* @param <E> 输入集合类型
* @param <T> 输出集合类型
* @return 返回集合
*/
public static <E, T> List<T> convertListToList(List<E> input, Class<T> clazz) {
List<T> output = Lists.newArrayList();
if (CollectionUtils.isNotEmpty(input)) {
for (E source : input) {
T target = BeanUtils.instantiate(clazz);
BeanUtils.copyProperties(source, target);
output.add(target);
}
}
return output;
}
示例
有以下三个类，User、Cust、Student：
@Data
public class User {
private String name;
private String password;
private String email;
}
@Data
public class Cust {
private String name;
private String password;
private String email;
private String phone;
}
@Data
public class Student {
private String name;
private String password;
}
工具类：
import com.google.common.collect.Lists;
import org.apache.commons.collections.CollectionUtils;
import org.springframework.beans.BeanUtils;
import java.util.List;
/**
* @Description: 对象之间进行赋值
* @Date: 2020/9/25 9:55
*/
public class AssignmentObject {
/**
* 对象属性拷贝
* 将源对象的属性拷贝到目标对象
* @param source 源对象
* @param target 目标对象
*/
public static void copyProperties(Object source, Object target) {
BeanUtils.copyProperties(source, target);
}
/**
* @param input 输入集合
* @param clazz 输出集合类型
* @param <E> 输入集合类型
* @param <T> 输出集合类型
* @return 返回集合
*/
public static <E, T> List<T> convertListToList(List<E> input, Class<T> clazz) {
List<T> output = Lists.newArrayList();
if (CollectionUtils.isNotEmpty(input)) {
for (E source : input) {
T target = BeanUtils.instantiate(clazz);
BeanUtils.copyProperties(source, target);
output.add(target);
}
}
return output;
}
}
测试类：分别测试对象之间的属性赋值与List之间的属性赋值
public class Demo {
public static void main(String[] args) {
User user = new User();
user.setName("admin");
user.setPassword("admin");
user.setEmail("123@qq.com");
System.out.println("user:" + user);
// 将user的属性分别赋给cust和student
Cust cust = new Cust();
AssignmentObject.copyProperties(user, cust);
System.out.println("cust:" + cust);
Student student = new Student();
AssignmentObject.copyProperties(user, student);
System.out.println("student:" + student);
User user1 = new User();
user1.setName("demo");
user1.setPassword("demo");
user1.setEmail("demo@qq.com");
System.out.println("user1:" + user);
// 将users赋值给List<Cust>和List<Student>
List<User> users = new ArrayList<>();
users.add(user);
users.add(user1);
System.out.println("users:" + users);
List<Cust> custs = AssignmentObject.convertListToList(users, Cust.class);
System.out.println("custs:" + custs);
List<Student> students = AssignmentObject.convertListToList(users, Student.class);
System.out.println("students:" + students);
}
}
