Java集合框架的接口和类层次关系结构图

时间:2021-06-19 14:27:55

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*接口,然而”Collections“是一个提供了一系列静态方法的集合工具类;

Java集合框架的接口和类层次关系结构图

Collection的类层次结构图

Java集合框架的接口和类层次关系结构图

Map的类层次结构图

Java集合框架的接口和类层次关系结构图

总结

Java集合框架的接口和类层次关系结构图

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);
} }

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/