java基础之对properties配置文件的读写操作

来源：互联网发布：中国历史延续知乎编辑：程序博客网时间：2024/04/30 14:35
1、test.properties文件处于与src并列的位置，即根目录
这里写图片描述
2、源码
/** * 1.clipse：test.properties文件处于与src并列的位置，即根目录 *//** * 2.Android studio：test.properties文件放于assets文件夹下 * 读入输出流方法：InputStream in =getAssets().open("test.txt");   * 获得AssetManger 对象, 调用其open 方法取得  对应的inputStream对象  */public class PropertiesTest {    /**     * 1.读取配置文件     *      * @throws IOException     */    @Test    public void read() throws IOException {        Properties properties = new Properties();        File file = new File("test.properties");        FileInputStream fis = new FileInputStream(file);        try {            // 读取配置文件            properties.load(fis);        } catch (IOException e1) {            e1.printStackTrace();        }        Set<Object> keySet = properties.keySet();        for (Object object : keySet) {            System.out.println(object.toString() + ":"                    + properties.getProperty(object.toString()));        }    }    /**     * 2.向配置文件写入内容     *      * @throws IOException     */    @Test    public void write() throws IOException {        Properties properties = new Properties();        String file = "test.properties";        OutputStream fos = new FileOutputStream(file);        properties.setProperty("aa", "123");        properties.setProperty("bb", "456");        properties.setProperty("cc", "789");        properties.setProperty("name", "张三");        properties.store(fos, "保存文件");        fos.close();    }    /**     * 3.对配置文件的修改     *      * @throws IOException     */    @Test    public void update() throws IOException {        Properties properties = new Properties();        File file = new File("test.properties");        FileInputStream fis = new FileInputStream(file);        FileOutputStream fos = new FileOutputStream(file);        try {            // 读取配置文件            properties.load(fis);        } catch (IOException e1) {            e1.printStackTrace();        }        properties.setProperty("name", "李四");        properties.setProperty("age", "222");        properties.setProperty("age3", "222");        properties.store(fos, "更新配置文件");        fos.close();        fis.close();    }    /**     * 4.删除配置文件中的key     * @throws IOException     *     */    @Test    public void delete() throws IOException{       Properties properties = new Properties();       File file = new File("test.properties");       FileInputStream fis = new FileInputStream(file);         try {            // 读取配置文件            properties.load(fis);        } catch (IOException e1) {            e1.printStackTrace();        }        //必须先用map将所有的内容先保存,不然一删除,原来的内容都没了       Map<String, String> map = new HashMap<String, String>();       Set<Object> keySet = properties.keySet();       System.out.println(keySet.size());       for (Object object : keySet) {           String key = (String) object;           String value = (String) properties.get(key);           System.out.println(key+"="+value);           map.put(key, value);       }       //删除key       map.remove("age3");       properties.remove("age3");       for (java.util.Map.Entry<String, String> entry: map.entrySet()) {           properties.setProperty(entry.getKey(), entry.getValue());       }       FileOutputStream fos = new FileOutputStream(file);       properties.store(fos, "删除配置文件中的key:age3");            fos.close();       fis.close();    }  }
0 0