java读写properties文件的方法

曾经终败给现在 2023-10-11 13:55 41阅读 0赞

## 1.读取properties： ##

代码：

import java.io.File;
    import java.io.FileInputStream;
    import java.io.InputStream;
    import java.net.URL;
    import java.util.Properties;
    
    public class PropertiesUtil {
        
        /**
         * 获取指定路径下对应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();    //创建Properties对象
            InputStream in = null;
            try {
        
                in = new FileInputStream(propertiesPath);   //创建输入流文件对象
                prop.load(in);
                re=prop.getProperty(key);//加载输入流
            } catch (Exception e) {
        
                System.out.println(e.getMessage());
            } finally {
        
                try {
        
                    in.close();                         //关闭输入流
                } catch (Exception e) {
        
                    System.out.println(e.getMessage());
                }
            }
            return re;
        }
    
        /**
         * 通过文件名获取构建路径下对应的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);
        }
    
    }

实例:

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);
        }

测试结果:  
![在这里插入图片描述][20200403161518866.PNG]

## 2.写入properties文件 ##

代码:

/**
         * 写入properties
         * @param propertiesPath
         * @param key
         * @param value
         */
        public static void writeProperties(String propertiesPath,String key,String value) {
        
            Properties prop = new Properties();    //创建Properties对象
            InputStream in = null;
            FileOutputStream oFile = null;
    
            try {
        
                in = new FileInputStream(propertiesPath);   //创建输入流文件对象
                prop.load(in);                          //加载输入流
                prop.setProperty(key, value);           //修改值
                oFile = new FileOutputStream(propertiesPath);   //创建输出流文件对象
                prop.store(oFile, "");                  //将Properties对象的属性保存到输出流指定文件
            } catch (Exception e) {
        
                System.out.println(e.getMessage());
            } finally {
        
                try {
        
                    oFile.close();                      //关闭输出流
                } catch (Exception e) {
        
                    System.out.println(e.getMessage());
                }
                try {
        
                    in.close();                         //关闭输入流
                } catch (Exception e) {
        
                    System.out.println(e.getMessage());
                }
            }
        }

实例:

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");
    
        }

测试结果:  
![在这里插入图片描述][2020040316153829.PNG]

[20200403161518866.PNG]: https://img-blog.csdnimg.cn/20200403161518866.PNG
[2020040316153829.PNG]: https://img-blog.csdnimg.cn/2020040316153829.PNG