Map Demo

import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;


public class Demo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String str = "987654321";
		char[] ch = str.toCharArray();
		Arrays.sort(ch);
		System.out.println(Arrays.binarySearch(ch, '7'));
		StringBuffer sb = new StringBuffer();
		for (char c : ch) {
			sb.append(c);
		}
		System.out.println(sb.toString());
		Map map = new HashMap();
		map.put(null, null);
		map.put("1 ", " 2 x");
		System.out.println(map.entrySet());
		Iterator it = map.keySet().iterator();
		Iterator it1 = map.entrySet().iterator();
		while (it1.hasNext()) {
			System.out.println(it1.next());
		}
		while (it.hasNext()) {
			Object key = it.next();
			System.out.println("key is " + key);
			System.out.println("value is " + map.get(key));
		}
		Map model = new HashMap();
		model.put("xxx", 1);
		Integer xxx = (Integer) model.get("xxx");
		if(!model.isEmpty()){
			System.out.println(model.size());
			Integer l= Integer.valueOf(xxx);
			System.out.println(model.hashCode()+"----"+l);
		}
	}

}