第一篇 集合与容器

package com.zzp.demo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
 * 
 * 泛型的使用
 * @author java
 *
 */
public class TestGeneric {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        MyCollection<String> mc = new MyCollection<String>();
        mc.set("dhfjs", 0);
                
        String b = (String) mc.get(0);
        System.out.println("b:"+b);
        List list = new ArrayList();
        Map map = new HashMap();
    }

}

class MyCollection<E>{
    Object[] objs = new Object[5];
    
    public void set(E e,int index){
        objs[index] = e;
    }    
    public E get(int index){
        return (E)objs[index];
    }
}

package com.zzp.demo;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * 
 * 测试collection中的方法
 * @author java
 *
 */
public class TestList {
    public static void main(String[] args) {    
        test03();
    }
    
    public static void test01(){
    Collection<String> c = new ArrayList<>();
        
        System.out.println(c.size());
        System.out.println(c.isEmpty());
        
        c.add("张三");
        c.add("张四");
        System.out.println(c);
        System.out.println(c.size());
        
        c.contains("张三");
        
        Object[] a = c.toArray();
        c.remove("张四");
        System.out.println(c);
        
        c.clear();
        System.out.println(c.size());
    }
    
    public static void test02(){
        List<String> list01 = new ArrayList<>();
        list01.add("aa");
        list01.add("bb");
        list01.add("cc");
        
        List<String> list02 = new ArrayList<>();
        list02.add("aa");
        list02.add("dd");
        list02.add("ee");
        
        System.out.println("list01:"+list01);
        
        list01.addAll(list02);
        System.out.println("list01:"+list01);
        
        list01.removeAll(list02);
        System.out.println("list01:"+list01);
        
        list01.retainAll(list02);
        System.out.println("list01:"+list01);
        
        System.out.println(list01.contains(list02));
    }
    
    public static void test03(){
        List<String> list = new ArrayList<>();
        list.add("A");
        list.add("B");
        list.add("C");
        list.add("D");
        System.out.println(list);
        
        list.add(2, "张三");
        System.out.println(list);
        
        list.remove(2);
        System.out.println(list);
        
        list.set(2, "李四");
        System.out.println(list);
        
        System.out.println(list.get(0));
        
        list.add("C");
        list.add("B");
        list.add("A");
        System.out.println(list);
        
        System.out.println(list.indexOf("A"));
        System.out.println(list.lastIndexOf("A"));
        
        System.out.println(list.indexOf("张三"));
        System.out.println(list.lastIndexOf("张三"));
    }
}