【Simple Java】Java集合框架的接口和類層次關系結構圖,simplejava
Collection和Collections的區別
首先要說的是,"Collection" 和 "Collections"是兩個不同的概念;
如下圖所示,"Collection"是集合類(Collection)的頂級接口,然而”Collections“是一個提供了一系列靜態方法的集合工具類;
Collection的類層次結構圖
Map的類層次結構圖
總結
代碼示例
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
結果打印:
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}
譯文鏈接:http://www.programcreek.com/2009/02/the-interface-and-class-hierarchy-for-collections/