安卓文件的读和写的实现

来源：互联网发布：淘宝照片分辨率多少编辑：程序博客网时间：2024/05/16 09:04

说明：

文件保存路径为安卓默认路径,/data/应用包名(全名)/files

一、activity

package com.example.filerw;import com.example.server.FileServer;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.widget.EditText;import android.widget.TextView;public class MainActivity extends Activity {private EditText contentEdit;private String file_name="file.txt";private FileServer fileServer;private TextView showText;protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);contentEdit = (EditText)findViewById(R.id.content);showText = (TextView)findViewById(R.id.showText);fileServer = new FileServer(getApplicationContext());}public void MainClick(View v){switch (v.getId()) {case R.id.save:String str = contentEdit.getText().toString();fileServer.save(file_name, str);break;case R.id.read:String show = fileServer.read(file_name);showText.setText(show);break;default:break;}}//菜单public boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.main, menu);return true;}}

二、主要实现代码

package com.example.server;import java.io.ByteArrayOutputStream;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import org.apache.http.util.EncodingUtils;import android.content.Context;public class FileServer {private Context context;private FileInputStream in;private FileOutputStream out;public FileServer(Context context){this.context = context;}/** * 保存 * @param name */public void save(String name,String content){try {out = context.openFileOutput(name, Context.MODE_PRIVATE);out.write(content.getBytes());out.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (Exception e) {System.out.println(e.toString());}}/** * 读文件 * @param name * @return */public String read(String name){String file_content = null;try {ByteArrayOutputStream byteOut = new ByteArrayOutputStream();in = context.openFileInput(name);//具有缓冲实例的打开文件byte[] buf = new byte[1024];while((in.read(buf))!=-1){byteOut.write(buf);//将读出来的数据写到缓存中}file_content = EncodingUtils.getString(byteOut.toByteArray(),"GBK");//转码byteOut.close();in.close();} catch (FileNotFoundException e) {e.printStackTrace();}catch (Exception e) {System.out.println(e.toString());}return file_content;}}

三、xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity"     android:padding="0dp"    >    <EditText         android:id="@+id/content"  android:inputType="text"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:hint="请输入内容"        android:textSize="16sp"        android:background="@drawable/edit_xmlbg"        android:minHeight="30dp"        />    <TextView         android:id="@+id/showText"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_below="@+id/content"        />    <Button         android:id="@+id/save"        android:onClick="MainClick"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="18sp"        android:text="save"        android:layout_alignParentBottom="true"        /><Button         android:id="@+id/read"        android:onClick="MainClick"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="18sp"        android:text="read"        android:layout_alignParentBottom="true"        android:layout_toRightOf="@+id/save"        /></RelativeLayout>

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