import java.util.*; // 自定义类使用Collections进行比较时需要实现的函数 // implements Comparable<Test> // public int compareTo(T obj) // public String toString() // public boolean equals(Object o) //经典数据类型对自定义类的适配 class Test implements Comparable<Test>{ public String line; public Integer num; public Boolean blen; public Test() { this.line = new String("NULL"); this.num = 0; this.blen = false; this.printSelf(); } public Test(String line,Integer num,Boolean blen) { this.line = line; this.num = num; this.blen = blen; this.printSelf(); } // public int compareTo(T obj) public int compareTo(Test obj) { int result = 3; if(this.line.compareTo(obj.line) < 0) { result = -1; }else if(this.line.equals(obj.line)) { result = 0; }else { result = 1; } System.out.println("[Once] = " + result); return result; } // public String toString() @Override public String toString() { return "Test [line=" + line + ", num=" + num + ", blen=" + blen + "]"; } public void printSelf() { System.out.println(this.toString()); } //重写用于contains()函数 // public boolean equals(Object o) @Override public boolean equals(Object obj) { if(obj == null) { return false; }else if(obj instanceof Test) { Test t = (Test)obj; if(this.line.equals(t.line) && this.num.equals(t.num) && this.blen.equals(t.blen)) { return true; } } return false; } } public class Main{ public static void main(String[] args) { //链表 List<Test> list = new ArrayList<Test>(); list.add(new Test("asv",120,false)); list.add(new Test("asd",123,true)); list.add(new Test()); list.add(new Test("asf",121,true)); // //排序操作 // Collections.sort(list); // // System.out.println("======================="); // //// System.out.println(list); // for(int i=0;i<list.size();i++) { // System.out.println(list.get(i)); // } //包含操作 boolean ans = list.contains(new Test("asd",123,true)); System.out.println(ans); //如果没有实现equals(Object)函数则返回值为false } }
OK