java对properties配置文件的读写操作

Test.properties

name:\u5F20\u4E09

password:\u5BC6\u7801

age:22

PropertiesTest.java

/**
     * 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);
      
       properties.load(fis);
      
       Set<Object> keySet = properties.keySet();
      
       for (Object object : keySet) {
           System.out.println(object.toString()+":"+properties.getProperty(object.toString()));
       }
    }

后台打印结果

age:22

password:密码

name:张三

PropertiesTest.java

/**
     * 向配置文件写入内容
     * @throws IOException
     */
    @Test
    public void write() throws IOException {
       Properties properties = new Properties();
      
       String file = "aa.properties";
       FileOutputStream 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();
    }

aa.propertiest

#\u4FDD\u5B58\u6587\u4EF6

#Sun Jan 25 14:06:25 CST 2015

name=\u5F20\u4E09

aa=123

bb=456

cc=789

Test.properties

Age=22

Password=密码

Name=张三

PropertiesTest.java

  /**
     * 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);
      
       properties.load(fis);
      
       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();
      
    }

Test.properties

#\u66F4\u65B0\u914D\u7F6E\u6587\u4EF6

#Sun Jan 25 15:20:40 CST 2015

age=222

name=\u674E\u56DB

password=\u5BC6\u7801

age3=222

Test.properties

#\u66F4\u65B0\u914D\u7F6E\u6587\u4EF6

#Sun Jan 25 15:20:40 CST 2015

age=222

name=\u674E\u56DB

password=\u5BC6\u7801

age3=222

PropertiesTest.java

/**
     * 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);
             
       properties.load(fis);   
      
       //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();
      
    }  

Test.properties

#\u5220\u9664\u914D\u7F6E\u6587\u4EF6\u4E2D\u7684key:age3

#Sun Jan 25 15:23:58 CST 2015

age=222

name=\u674E\u56DB

password=\u5BC6\u7801

PropertieTest.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
 
import org.junit.Test;
 
 
public class PropertiesTest {
 
    public static void main(String[] args) {
 
    }
    /**
     * 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);
             
       properties.load(fis);   
      
       //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();
      
    }
   
    /**
     * 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);
      
      
      
       properties.load(fis);
      
       //必须先用map将所有的内容先保存,不然一更新,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);
       }
      
       map.put("name", "李四");
       map.put("age", "222");
       map.put("age3", "222");
      
      
       for (java.util.Map.Entry<String, String> entry: map.entrySet()) {
           properties.setProperty(entry.getKey(), entry.getValue());
       }
       FileOutputStream fos = new FileOutputStream(file);
      
       properties.store(fos, "更新配置文件");
      
       fos.close();
      
       fis.close();
      
    }
   
   
    /**
     * 向配置文件写入内容
     * @throws IOException
     */
    @Test
    public void write() throws IOException {
       Properties properties = new Properties();
      
       String file = "aa.properties";
       FileOutputStream 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();
    }
   
   
    /**
     * 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);
      
       properties.load(fis);
      
       Set<Object> keySet = properties.keySet();
      
       for (Object object : keySet) {
           System.out.println(object.toString()+"="+properties.getProperty(object.toString()));
       }
    }
 
}