Java获取Txt文件

package oo;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.util.Properties;

public class user {

     public static void main(String[] args) {

          Properties a=new Properties();

          

          try {

              a.load(new FileReader("user.txt"));

          } catch (Exception e) {

              // TODO: handle exception

              System.out.println("文件不存在");

          }

          a.setProperty("age","435" );

          a.setProperty("id", "2");

          //如果键不存在，则新加键值对，如果键存在，则修改值

          a.setProperty("pwd", "898");

          

          try {

              //保存资源文件对象中所有的键值，第一个参数为写入流，第二个参数为注释

              a.store(new FileWriter("user.txt"), null);

          } catch (IOException e) {

              // TODO Auto-generated catch block

              e.printStackTrace();

          }

     }

     

     

}

登录

package oo;

import java.io.FileReader;

import java.util.Properties;

import javax.swing.JOptionPane;

public class login {

     public static void main(String[] args) {

          Properties a=new Properties();

          String q=JOptionPane.showInputDialog(null, "请输入你的账号");

          int w=Integer.parseInt(JOptionPane.showInputDialog(null,"请输入你的密码"));

          try {

              a.load(new FileReader("Login.txt"));

          } catch (Exception e) {

              // TODO: handle exception

              JOptionPane.showMessageDialog(null, "文件不存在");

          }

          String aName=a.getProperty("userName");

          String aPwd=a.getProperty("pwd");

          if(q.equals(aName)&&q.equals(aPwd)){

              JOptionPane.showMessageDialog(null, "登录成功");

          }else{

              JOptionPane.showMessageDialog(null, "输入错误");

          }

     }

}

代码

现在项目下面创建一个test.txt文件

package oo;

import java.io.FileReader;

import java.util.Properties;

public class java {

     public static void main(String[] args) {

          //创建资源文件对象

          Properties q=new Properties();

          try {

              //获取文件中所有的键值对，存放进行q对象

              q.load(new FileReader("test.txt"));

          } catch (Exception e) {

              // TODO: handle exception

              System.out.println("文件不存在");

          }

          //根据建得到值

          String s=q.getProperty("name");

          System.out.println(s);

     }

}