Android(安卓)读取和保存文件（手机内置存储器）

1:activity_main.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">    <TextView         android:id="@+id/tv_filename"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="文件名称"/>    <EditText         android:id="@+id/et_filename"        android:layout_below="@id/tv_filename"        android:layout_width="match_parent"        android:layout_height="wrap_content"/>        <TextView         android:id="@+id/tv_content"        android:layout_below="@id/et_filename"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="文件内容"/>    <EditText         android:id="@+id/et_content"        android:layout_below="@id/tv_content"        android:layout_width="match_parent"        android:layout_height="wrap_content"/>        <Button         android:id="@+id/btn_save"        android:layout_below="@id/et_content"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="保存"/>        <Button         android:id="@+id/btn_read"        android:layout_below="@id/btn_save"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="读取"/></RelativeLayout>

2:文件操作类:FileService.java

public class FileService {private Context context=null;public FileService(Context context){this.context=context;}//save filepublic void saveFile(String filename,String content) throws Exception{FileOutputStream out=context.openFileOutput(filename, Context.MODE_PRIVATE);out.write(content.getBytes());out.close();}//read filepublic String readFile(String filename)throws Exception{FileInputStream is=context.openFileInput(filename);byte b[]=new byte[1024];int len=0;ByteArrayOutputStream baos=new ByteArrayOutputStream();//先把数据写入内存while((len=is.read(b))!=-1){baos.write(b,0,len);}//从内存中读取数据byte data[]=baos.toByteArray();baos.close();is.close();return new String(data);}}

3:MainActivity.java

public class MainActivity extends Activity {private FileService fileService=null;private Button btnSave=null,btnRead=null;private EditText etFilename=null;private EditText etContent=null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btnSave=(Button)findViewById(R.id.btn_save);btnRead=(Button)findViewById(R.id.btn_read);etFilename=(EditText)findViewById(R.id.et_filename);etContent=(EditText)findViewById(R.id.et_content);fileService=new FileService(MainActivity.this);btnSave.setOnClickListener(new OnClickListener(){public void onClick(View view){String filename=etFilename.getText().toString();String content=etContent.getText().toString();try {fileService.saveFile(filename, content);Toast.makeText(MainActivity.this, "Save file success!", Toast.LENGTH_SHORT).show();} catch (Exception e) {Toast.makeText(MainActivity.this, "Save file error!", Toast.LENGTH_SHORT).show();}}});btnRead.setOnClickListener(new OnClickListener(){public void onClick(View view){String filename=etFilename.getText().toString();try {String text=fileService.readFile(filename);etContent.setText(text);} catch (Exception e) {Toast.makeText(MainActivity.this, "Read file error!", Toast.LENGTH_SHORT).show();}}});}}

4:运行结果

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