propertiesutil.java

java写的一个通讯录的程序。使用的是AWT组件

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Properties;
import javax.swing.JOptionPane;
import java.util.Arrays;


public class PropertiesUtil {
	private Properties pro;
	private String fileName;
	public PropertiesUtil(String fileName){
		this.fileName = fileName;
		pro = new Properties();
		
	}
	public void load(){
		try {
			pro.load(new FileInputStream(fileName));
		} catch (FileNotFoundException e) {
			System.out.println("文件没有找到！");
			e.printStackTrace();
		} catch (IOException e) {
			System.out.println("文件找到，但出现其他错误！");
			e.printStackTrace();
		}
	}
	
	public String read(String key){
		return pro.getProperty(key);	
	}
	
	public boolean containKey(String key){
		return pro.contains(key);
	}
	
	public void setProperties(String key,String value){
		pro.setProperty(key, value);
	}
	
	public void save(){
		try {
			pro.store(new FileOutputStream(fileName,true), null);
			JOptionPane.showMessageDialog(null,"保存成功！");
		} catch (FileNotFoundException e) {
			System.out.println("文件没有找到！");
			e.printStackTrace();
		} catch (IOException e) {
			System.out.println("文件找到，但出现其他错误！");
			e.printStackTrace();
		}
	}
	
	public String[] getAllKeys(){
		List<String> keys = new ArrayList<String>();
		load();
		// 得到所有键,并遍历
		for (Enumeration e = pro.propertyNames(); e.hasMoreElements();) {

			String s = (String) e.nextElement(); //遍历所有元素

			// 以.name结尾的串
			if (s.endsWith(".no")) {
				s = s.substring(0, s.length() - 3);
				keys.add(s);
				// System.out.println(s);
			}

			// System.out.println(e.nextElement());
		}

		String[] users = new String[keys.size()]; // 取集合大小
		
		for (int i = 0; i < keys.size(); i++) {
			users[i] = keys.get(i);
		}
		Arrays.sort(users);

		return users;
	}
}