Java对象List使用陷阱

Java由一个对象List筛选或者浅复制得到的另一个对象List里面的引用和原List里的引用指向同一个地址，修改其中一个List里的共有对象时，同时会影响到两个List里存放的对象

package test;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class CodeTest {
    
    private String value;
    
    public CodeTest(String value) {
        this.value = value;
    }
    
    public String getValue() {
        return value;
    }
    
    public void setValue(String value) {
        this.value = value;
    }
    
    public static void main(String[] args) {
        


        
    
        List list1 = new ArrayList<>();
        list1.add(new CodeTest("a"));
        list1.add(new CodeTest("b"));
        list1.add(new CodeTest("c"));
        list1.add(new CodeTest("d"));
    
        List list2 = list1.stream().filter(s -> s.value.equals("a") || s.value.equals("b")).collect(Collectors.toList());
    
        System.out.println(list1);
        System.out.println(list2);
        
        System.out.println("=================================");
        for (CodeTest codeTest : list1) {
            System.out.println(codeTest.value);
        }
        System.out.println("=================================");
        for (CodeTest codeTest : list2) {
            System.out.println(codeTest.value);
        }
        System.out.println("=================================");
//        list2.set(0,"1");
//        list2.set(1,"2");
    
        
        //修改list2里面对象的属性值，list1里的对象的属性值也会改变
        for (CodeTest codeTest : list2) {
            codeTest.setValue("change");
        }
    
        for (CodeTest codeTest : list1) {
            System.out.println(codeTest.value);
        }
        System.out.println("=================================");
        for (CodeTest codeTest : list2) {
            System.out.println(codeTest.value);
        }
        System.out.println("=================================");
    
        System.out.println(list1);
        System.out.println(list2);
    }
}

运行结果：