java中读写文件

1、读文件中的某项值：       

//根据文件路径名加载对应的文件   

InputStream inputStream = new FileInputStream(this.componentFilePath);

//设定Properties

Properties p = new Properties();

//将InputStream加载到Properties中

p.load(inputStream);

//获取特定项的值

String componentID = p.getProperty(APP_COMPONENTID);

//返回特定的值

 return componentID;

2、写文件

//创建File对象

 File ft = new File(this.componentFilePathTemp);

//createNewFile
 ft.createNewFile();

//定义FileWriter

FileWriter fw = null;

//定义BufferedWriter

BufferedWriter bw = null;
  try {
            fw = new FileWriter(ft);
            bw = new BufferedWriter(fw);

            //写数据到Buffer中
            bw.write(APP_COMPONENTID + "=" + this.componentID);

           //清空Buffer
            bw.flush();

}

catch(IOException e){

          e.printStackTrace();

}