浅谈Java中Properties类的详细使用

@Test
public void printTest(){
    Properties properties=System.getProperties();
    properties.list(System.out);
}

@Test
public void name1Test(){
    try{
        Properties properties=new Properties();
        //用的是磁盘符的绝对路径 
        InputStream input=new BufferedInputStream(new FileInputStream("D:\\workspace\\JavaLearn\\src\\jdbc.properties"));
        properties.load(input);
        properties.list(System.out);
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void name2Test(){
    try{
        Properties properties=new Properties();  // 用/文件名， / 表示根目录
        InputStream input=PropertiesTest.class.getClass().getResourceAsStream("/jdbc.properties");
        properties.load(input);
        Enumeration<String> names=(Enumeration<String>) properties.propertyNames();
        while(names.hasMoreElements()){
            //这是key值
            String key=names.nextElement();
            String value=properties.getProperty(key);
            System.out.println(key+"="+value);
        }
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void name3Test(){
    try{
        Properties properties=new Properties();
        //直接写src 类路径下的文件名
        InputStream input=PropertiesTest.class.getClassLoader().getResourceAsStream("jdbc.properties");
        properties.load(input);
        
        //把key值转换成set 的形式，遍历set
        Set<String> names=properties.stringPropertyNames();
        Iterator<String> iterator=names.iterator();
        while(iterator.hasNext()){
            String key=iterator.next();
            String value=properties.getProperty(key);
            System.out.println(key+"="+value);
        }
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void name3Test(){
    try{
        Properties properties=new Properties();
        InputStream input=PropertiesTest.class.getClassLoader().getResourceAsStream("jdbc.properties");
        properties.load(input);
        //String value=properties.getProperty("jdbc.url");
        String value=properties.getProperty("jdbc.url1","没有该key值");
        System.out.println("输出值:"+value);
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void writeTest(){
    try{
        Properties properties=new Properties();
        InputStream input=PropertiesTest.class.getClassLoader().getResourceAsStream("jdbc.properties");
        properties.load(input);
        
        //多添加几个值。
        properties.setProperty("name","两个蝴蝶飞");
        properties.setProperty("sex","男");

        //properties.put("name","两个蝴蝶飞");  可以用继承Hashtable 的put 方法写入值
        // properties.put("sex","男");
        
        //将添加的值，连同以前的值一起写入 新的属性文件里面。
        OutputStream out=new FileOutputStream("D:\\jdbc.properties");
        properties.store(out,"填充数据");
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void write2Test(){
    try{
        Properties properties=new Properties();
        //用绝对路径
        InputStream input=new BufferedInputStream(new FileInputStream("D:\\workspace\\JavaLearn\\src\\jdbc.properties"));
        properties.load(new InputStreamReader(input,"utf-8"));
            //多添加几个值。
        properties.setProperty("name","两个蝴蝶飞");
        properties.setProperty("sex","男");
        
        OutputStream output=new FileOutputStream("D:\\jdbc.properties");
        OutputStreamWriter out=new OutputStreamWriter(output,"utf-8");
        properties.store(out,"填充数据");
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void xmlWriteTest(){
    try{
        //处理成编码样式。
        Properties properties=new Properties();
        
            //多添加几个值。
        properties.setProperty("name","两个蝴蝶飞");
        properties.setProperty("sex","男");
        OutputStream output=new FileOutputStream("D:\\jdbc.xml");
        //编码设置成utf-8的形式。 
        properties.storeToXML(output,"填充到xml","utf-8");
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

@Test
public void xmlReadTest(){
    try{
        Properties properties=new Properties();
        InputStream input=new BufferedInputStream(new FileInputStream("D:\\jdbc.xml"));
        properties.loadFromXML(input);
        properties.list(System.out);
        
    }catch(Exception e){
        e.printStackTrace();
    }
}