Properties操作例子类

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.apache.log4j.Logger;
public class SystemParameter {
	private static Logger logger = Logger.getLogger(SystemParameter.class);
	private static String msgTemplate1;
	private static String msgTemplate2;
	private static String msgTemplate3;
	private static final Properties properties;
	public static Map<String, String> proMap=new HashMap<String, String>();
	
	private SystemParameter() {
	}
	static {
		properties = new Properties();
		FileInputStream fis = null;
		try {
			fis = new FileInputStream(Thread.currentThread()
					.getContextClassLoader().getResource(
							"systemParamter.properties").toString()
					.substring(6));
			properties.load(fis);
			msgTemplate1 = properties.getProperty("msgTemplate1");
			proMap.put("msgTemplate1", msgTemplate1);
			msgTemplate2 = properties.getProperty("msgTemplate2");
			proMap.put("msgTemplate2", msgTemplate2);
			msgTemplate3 = properties.getProperty("msgTemplate3");
			proMap.put("msgTemplate3", msgTemplate3);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				fis.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	public static String getMsgTemplate1() {
		return proMap.get("msgTemplate1");
	}
	public static String getMsgTemplate2() {
		return proMap.get("msgTemplate2");
	}
	public static String getMsgTemplate3() {
		return proMap.get("msgTemplate3");
	}
	
	// 修改通知模板
	public static void modifyMsgTemplate(String key,String template) {
		logger.debug("################" + template);
		properties.setProperty(key, template);
		FileOutputStream fos = null;
		try {
			fos = new FileOutputStream(Thread.currentThread()
					.getContextClassLoader().getResource(
							"systemParamter.properties").toString()
					.substring(6));
			properties.store(fos, "");
			proMap.put(key, template);
			fos.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
   
}

另一个例子

public   class  Test {   
     private   static  Properties properties =  new  Properties();   
  
     public   static   void  main(String[] args) {   
         try  {   
            InputStream is = Test. class .getClassLoader().getResourceAsStream( "cache.properties" );   
            properties.load(is);   
            String size = properties.getProperty( "cache.size" );   
            writeLog( "配置成功！"  + size);   
        }  catch  (FileNotFoundException e) {   
            writeLog( "配置文件不存在！"  + e.getMessage());   
        }  catch  (IOException e) {   
            writeLog( "读取配置文件IO错误！"  + e.getMessage());   
        }   
    }   
  
     public   static   void  writeLog(String strLog) {   
        System.out.println(strLog);   
    }   
}  
 
 
 
1.使用java.util.ResourceBundle类的getBundle()方法
示例： ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault());
return rb.getString("key");
注：该方法可以读jar包里的文件
2.使用java.util.PropertyResourceBundle类的构造函数
示例： InputStream in = new BufferedInputStream(new FileInputStream(name));
ResourceBundle rb = new PropertyResourceBundle(in);
return rb.getString("key");
3.使用java.util.Properties类的load()方法
示例： InputStream in = new BufferedInputStream(new FileInputStream(name));
Properties p = new Properties();
p.load(in);
return p.getProperties("key"); or return p.getProperties("key", "defaultValue");
4.使用class变量的getResourceAsStream()方法
示例： InputStream in = ClassName.class.getResourceAsStream(name);
Properties p = new Properties();
p.load(in);
return p.getProperties("key"); or return p.getProperties("key", "defaultValue");
5.使用class.getClassLoader()所得到的java.lang.ClassLoader的getResourceAsStream()方法
示例： InputStream in = ClassName.class.getClassLoader().getResourceAsStream(name);
Properties p = new Properties();
p.load(in);
return p.getProperties("key"); or return p.getProperties("key", "defaultValue");
6.使用java.lang.ClassLoader类的getSystemResourceAsStream()静态方法
示例： InputStream in = ClassLoader.getSystemResourceAsStream(name);
Properties p = new Properties();
p.load(in);
return p.getProperties("key"); or return p.getProperties("key", "defaultValue");
补充
Servlet中可以使用javax.servlet.ServletContext的getResourceAsStream()方法
示例：InputStream in = context.getResourceAsStream(path);
Properties p = new Properties();
p.load(in);
return p.getProperties("key"); or return p.getProperties("key", "defaultValue");
 
7.读jar外面的文件
FileInputStream fis;
Properties p = new Properties();
    fis = new FileInputStream(initfileName);
           prop.load(fis);
注：jar文件执行时，注意cmd路径必须与jar路径相同