java讀寫properties文件的方法

1.讀取properties：

代碼：

 
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
import java.util.Properties;

public class PropertiesUtil {
    /**
     * 獲取指定路徑下對應properties文件中的值
     * @param propertiesPath
     * @param key
     * @return
     */
    public static String readProperties(String propertiesPath,String key){
        String re=null;
        Properties prop = new Properties();    //創建Properties對象
        InputStream in = null;
        try {
            in = new FileInputStream(propertiesPath);   //創建輸入流文件對象
            prop.load(in);
            re=prop.getProperty(key);//加載輸入流
        } catch (Exception e) {
            System.out.println(e.getMessage());
        } finally {
            try {
                in.close();                         //關閉輸入流
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
        }
        return re;
    }

    /**
     * 通過文件名獲取構建路徑下對應的properties文件中的值
     * @param propertiesName
     * @param key
     * @return
     */
    public static String readPropertiesByConfigName(String propertiesName,String key){
        String re=null;
        Properties prop = new Properties();
        try {
            InputStream input = PropertiesUtil.class.getClassLoader().getResourceAsStream(propertiesName);
            prop.load(input);
            String data = prop.getProperty(key);
            return data;
        }catch (Exception e){
            e.printStackTrace();
        }
        return re;
    }
    public static void main(String[] args) {
        String re=readPropertiesByConfigName("pathConfig.properties","file.uploadDownLoad.path");
        System.out.println(re);
    }

}

實例:

private static final String userConfigProperties_Path="E:\\JAVA_Space\\dubbo\\src\\main\\resources\\userConfig.properties";
    public static void main(String[] args) {
        String re=PropertiesUtil.readProperties(userConfigProperties_Path,"a1");
        System.out.println(re);
    }

測試結果:

2.寫入properties文件

代碼:

/**
     * 寫入properties
     * @param propertiesPath
     * @param key
     * @param value
     */
    public static void writeProperties(String propertiesPath,String key,String value) {
        Properties prop = new Properties();    //創建Properties對象
        InputStream in = null;
        FileOutputStream oFile = null;

        try {
            in = new FileInputStream(propertiesPath);   //創建輸入流文件對象
            prop.load(in);                          //加載輸入流
            prop.setProperty(key, value);           //修改值
            oFile = new FileOutputStream(propertiesPath);   //創建輸出流文件對象
            prop.store(oFile, "");                  //將Properties對象的屬性保存到輸出流指定文件
        } catch (Exception e) {
            System.out.println(e.getMessage());
        } finally {
            try {
                oFile.close();                      //關閉輸出流
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
            try {
                in.close();                         //關閉輸入流
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
        }
    }

實例:

  private static final String userConfigProperties_Path="E:\\JAVA_Space\\dubbo\\src\\main\\resources\\userConfig.properties";
    public static void main(String[] args) {
       PropertiesUtil.writeProperties(userConfigProperties_Path,"a1","qwertyuiop");

    }

測試結果: