properties文件操作

import java.io.*;
import java.util.Enumeration;
import java.util.Properties;

//关于Properties类常用的操作
public class TestProperties {
    //根据Key读取Value
    public static String GetValueByKey(String filePath, String key) {
        Properties pps = new Properties();
        try {
            InputStream in = new BufferedInputStream(new FileInputStream(filePath));
            pps.load(in);
            String value = pps.getProperty(key);
            System.out.println(key + " = " + value);
            return value;

        }catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    //读取Properties的全部信息
    public static void GetAllProperties(String filePath) throws IOException {
        Properties pps = new Properties();
        InputStream in = new BufferedInputStream(new FileInputStream(filePath));
        pps.load(in);
        Enumeration en = pps.propertyNames(); //得到配置文件的名字

        while(en.hasMoreElements()) {
            String strKey = (String) en.nextElement();
            String strValue = pps.getProperty(strKey);
            System.out.println(strKey + "=" + strValue);
        }

    }

    //写入Properties信息
    public static void WriteProperties (String filePath, String pKey, String pValue) throws IOException {
        Properties pps = new Properties();

        InputStream in = new FileInputStream(filePath);
        //从输入流中读取属性列表（键和元素对）
        pps.load(in);
        //调用 Hashtable 的方法 put。使用 getProperty 方法提供并行性。
        //强制要求为属性的键和值使用字符串。返回值是 Hashtable 调用 put 的结果。
        OutputStream out = new FileOutputStream(filePath);
        pps.setProperty(pKey, pValue);
        //以适合使用 load 方法加载到 Properties 表中的格式，
        //将此 Properties 表中的属性列表（键和元素对）写入输出流
        pps.store(out, "Update " + pKey + " name");
    }

    public static void main(String [] args) throws IOException{
        GetAllProperties("src/main/resources/configuration.properties");
        WriteProperties("src/main/resources/configuration.properties","device_puk1", "dfsdfsdfsdfsdf");
        GetAllProperties("src/main/resources/configuration.properties");
        String value = GetValueByKey("src/main/resources/configuration.properties", "test1");
        System.out.println(value);
    }
}