【学习笔记】day2数据存储和界面展现第一天 08_使用api获取内部存储空间路径09_files文件夹与cache文件夹

来源：互联网发布：java快速开发框架编辑：程序博客网时间：2024/06/04 18:21

注意：在内部存储空间读写文件不需要权限

getFilesDir()方法用于获取/data/data/<application package>/files目录

getCacheDir()方法用于获取/data/data/<application package>/cache目录

package com.itheima.rwinrom;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.InputStreamReader;import android.os.Bundle;import android.app.Activity;import android.content.Context;import android.content.Intent;import android.view.Menu;import android.view.View;import android.widget.CheckBox;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {    private EditText et_name;private EditText et_pass;@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                       et_name = (EditText) findViewById(R.id.et_name);    et_pass = (EditText) findViewById(R.id.et_pass);        readAccount();    }    private void readAccount() {     //读取文件，回显数据//        File file = new File("data/data/com.itheima.rwinrom/info.txt");//    File file = new File(getFilesDir(), "info.txt");    File file = new File(getCacheDir(), "info.txt");        if(file.exists()){try {FileInputStream fis = new FileInputStream(file);//把字节流转换成字符流BufferedReader br = new BufferedReader(new InputStreamReader(fis));//读取文件中的文本String text = br.readLine();String s[] = text.split("&&");    //给输入框设置文本    et_name.setText(s[0]);    et_pass.setText(s[1]);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}    public void login(View v){    //获取用户输入的账号密码    String name = et_name.getText().toString();    String pass = et_pass.getText().toString();        CheckBox cb = (CheckBox) findViewById(R.id.cb);    //判断选框是否选中    if(cb.isChecked()){    //确定文件名和路径//    File file = new File("data/data/com.itheima.rwinrom/info.txt");        //返回一个File对象，封装的路径是data/data/com.itheima.rwinrom/files//    File file = new File(getFilesDir(), "info.txt");        //返回一个File对象，封装的路径是data/data/com.itheima.rwinrom/cache    File file = new File(getCacheDir(), "info.txt");    try {FileOutputStream fos = new FileOutputStream(file);//把账号密码写入本地文件fos.write((name + "&&" + pass).getBytes());fos.close();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}    }//    System.out.println("登录成功");    //创建吐司对话框    Toast t = Toast.makeText(this, "登录成功", 0);    //显示对话框    t.show();    }    }

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