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[Java教程]【Simple Java】Java集合框架的接口和类层次关系结构图


Collection和Collections的区别

首先要说的是,"Collection" 和 "Collections"是两个不同的概念;

如下图所示,"Collection"是集合类(Collection)的顶级接口,然而”Collections“是一个提供了一系列静态方法的集合工具类;

Collection的类层次结构图

Map的类层次结构图

总结

代码示例

package simplejava;import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.LinkedList;import java.util.List;import java.util.Map;import java.util.Set;public class Q7 {  public static void main(String[] args) {    List<String> a1 = new ArrayList<String>();    a1.add("Program");    a1.add("Creek");    a1.add("Java");    a1.add("Java");    System.out.println("ArrayList Elements");    System.out.print("\t" + a1 + "\n");         List<String> l1 = new LinkedList<String>();    l1.add("Program");    l1.add("Creek");    l1.add("Java");    l1.add("Java");    System.out.println("LinkedList Elements");    System.out.print("\t" + l1 + "\n");         Set<String> s1 = new HashSet<String>(); // 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<String, String> m1 = new HashMap<String, String>(); // 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);  }}

View Code

结果打印:

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}

 

译文链接:http://www.programcreek.com/2009/02/the-interface-and-class-hierarchy-for-collections/