Java HashSet和LinkedHashSet的用法

import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;


public class JavaTest {
	
	// HashSet不保证集合的迭代顺序；也许在某些时间迭代的顺序与插入顺序一致，但是不保证该顺序恒久不变。
	private static Set mSetInt = new HashSet();
	private static Set mSetString = new HashSet();
	
	// LinkedHashSet按照元素插入的顺序进行迭代，LinkedHashSet不是线程安全的。
	private static Set mLinkedSetInt = Collections.synchronizedSet(new LinkedHashSet());
	private static Set mLinkedSetString = Collections.synchronizedSet(new LinkedHashSet());

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		for (int i = 0; i  setIntIt = mSetInt.iterator();
		System.out.println("The sequence of HashSet for Integer:");
		while(setIntIt.hasNext()) {
			System.out.print(setIntIt.next() + " ");
		}
		System.out.println();
		
		System.out.println("The sequence of HashSet for String:");
		Iterator setStringIt = mSetString.iterator();
		while(setStringIt.hasNext()) {
			System.out.print(setStringIt.next() + " ");
		}
		System.out.println();
		
		System.out.println("The sequence of LinkedHashSet for Integer:");
		Iterator linkedSetIntIt = mLinkedSetInt.iterator();
		while(linkedSetIntIt.hasNext()) {
			System.out.print(linkedSetIntIt.next() + " ");
		}
		System.out.println();
		
		System.out.println("The sequence of LinkedHashSet for String:");
		Iterator linkedSetStringIt = mLinkedSetString.iterator();
		while(linkedSetStringIt.hasNext()) {
			System.out.print(linkedSetStringIt.next() + " ");
		}
		System.out.println();
	}

}