集合类接口和类层次关系图

时间 2019-11-09

标签集合接口层次关系栏目快乐工作繁體版

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1. Collection vs Collections

首先，“Collection”和“Collections”是两个不一样的概念。你能够从下面的层次关系图中看到，”Collection”是集合层次的顶层接口，而”Collections”是提供了操做集合类型的静态方法的类。java

2. 集合类层次关系图

下图是集合类的层次关系图git

3. Map的类层次结构关系图

下图是Map的类层次结构关系图github

4. 集合类总结

5. 代码示例

下面是一个简单的集合的例子：spa

 
        List a1 =  
        new 
         ArrayList(); 
       
        a1.add( 
        "Program" 
        ); 
       
        a1.add( 
        "Creek" 
        ); 
       
        a1.add( 
        "Java" 
        ); 
       
        a1.add( 
        "Java" 
        ); 
       
        System.out.println( 
        "ArrayList Elements" 
        ); 
       
        System.out.print( 
        "\t" 
         + a1 +  
        "\n" 
        ); 
       
        List l1 =  
        new 
         LinkedList(); 
       
        l1.add( 
        "Program" 
        ); 
       
        l1.add( 
        "Creek" 
        ); 
       
        l1.add( 
        "Java" 
        ); 
       
        l1.add( 
        "Java" 
        ); 
       
        System.out.println( 
        "LinkedList Elements" 
        ); 
       
        System.out.print( 
        "\t" 
         + l1 +  
        "\n" 
        ); 
       
        Set s1 =  
        new 
         HashSet();  
        // or new TreeSet() will order the elements; 
       
        s1.add( 
        "Program" 
        ); 
       
        s1.add( 
        "Creek" 
        ); 
       
        s1.add( 
        "Java" 
        ); 
       
        s1.add( 
        "Java" 
        ); 
       
        s1.add( 
        "tutorial" 
        ); 
       
        System.out.println( 
        "Set Elements" 
        ); 
       
        System.out.print( 
        "\t" 
         + s1 +  
        "\n" 
        ); 
       
        Map m1 =  
        new 
         HashMap();  
        // or new TreeMap() will order based on keys 
       
        m1.put( 
        "Windows" 
        ,  
        "2000" 
        ); 
       
        m1.put( 
        "Windows" 
        ,  
        "XP" 
        ); 
       
        m1.put( 
        "Language" 
        ,  
        "Java" 
        ); 
       
        m1.put( 
        "Website" 
        ,  
        "programcreek.com" 
        ); 
       
        System.out.println( 
        "Map Elements" 
        ); 
       
        System.out.print( 
        "\t" 
         + m1);

输出:code

 
        ArrayList Elements 
       
        [Program, Creek, Java, Java] 
       
        LinkedList Elements 
       
        [Program, Creek, Java, Java] 
       
        Set Elements 
       
        [tutorial, Creek, Program, Java] 
       
        Map Elements 
       
        {Windows=XP, Website=programcreek.com, Language=Java}