Java对象重写toString()方法，实现对象内容输出

覆盖父类toString()方法：

public class Person {private String id;private String name;public Person(String id, String name) {this.id = id;this.name = name;}public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "{id=" + this.id + ", name=" + this.name +"}";}}

main()方法测试：

public class MainTest {public static void main(String[] args) {List list = new ArrayList();Person p1 = new Person("1", "123");Person p2 = new Person("2", "123");Person p3 = new Person("1", "456");list.add(p1);list.add(p2);list.add(p3);for (Person person : list) {System.out.println(person.toString());}/*List result = list.stream().collect(Collectors.collectingAndThen(Collectors.toCollection(() -> new TreeSet(Comparator.comparing(p -> p.getId()))),ArrayList::new));*/}}

输出结果：