android资料操作

android文件操作
AndroidManifest.xml配置

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"      package="cn.itcast.file"      android:versionCode="1"      android:versionName="1.0">    <application android:icon="@drawable/icon" android:label="@string/app_name">         <uses-library android:name="android.test.runner" />        <activity android:name=".MainActivity"                  android:label="@string/app_name">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application>    <uses-sdk android:minSdkVersion="8" /><instrumentation android:name="android.test.InstrumentationTestRunner"  android:targetPackage="cn.itcast.file" android:label="Tests for My App" />    <!-- 在SDCard中创建与删除文件权限 --><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/><!-- 往SDCard写入数据权限 --><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>  </manifest> 

strings.xml

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="hello">Hello World, MainActivity!</string>    <string name="app_name">文件操作</string>    <string name="filename">文件名称</string>    <string name="filecontent">请输入文件的内容</string>    <string name="button">保存</string>    <string name="success">文件保存成功</string>    <string name="error">文件保存失败</string>    <string name="sdcarderror">SDCard不存在，或者写保护了</string></resources>

layout/main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    >	<TextView  	    android:layout_width="fill_parent" 	    android:layout_height="wrap_content" 	    android:text="@string/filename"	    />	<EditText	    android:layout_width="fill_parent" 	    android:layout_height="wrap_content" 	    android:id="@+id/filename"	    />	<TextView  	    android:layout_width="fill_parent" 	    android:layout_height="wrap_content" 	    android:text="@string/filecontent"	    />	<EditText	    android:layout_width="fill_parent" 	    android:layout_height="wrap_content" 	    android:minLines="3"	    android:id="@+id/filecontent"	    />	<Button	 	android:layout_width="wrap_content" 	    android:layout_height="wrap_content" 	    android:text="@string/button"	    android:id="@+id/button"	    /></LinearLayout>

FileService.java

package cn.itcast.service;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import android.content.Context;import android.os.Environment;public class FileService {	private Context context;		public FileService(Context context) {		this.context = context;	}	/**	 * 以私有文件保存内容	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void saveToSDCard(String filename, String content) throws Exception{		File file = new File(Environment.getExternalStorageDirectory(), filename);		FileOutputStream outStream = new FileOutputStream(file);		outStream.write(content.getBytes());		outStream.close();	}		/**	 * 以私有文件保存内容	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void save(String filename, String content) throws Exception{		FileOutputStream outStream = context.openFileOutput(filename, Context.MODE_PRIVATE);		outStream.write(content.getBytes());		outStream.close();	}	/**	 * 以追加方式保存内容	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void saveAppend(String filename, String content) throws Exception{// ctrl+shift+y / x		FileOutputStream outStream = context.openFileOutput(filename, Context.MODE_APPEND);		outStream.write(content.getBytes());		outStream.close();	}	/**	 * 保存内容,注：允许其他应用从该文件中读取内容	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void saveReadable(String filename, String content) throws Exception{		FileOutputStream outStream = context.openFileOutput(filename, Context.MODE_WORLD_READABLE);		outStream.write(content.getBytes());		outStream.close();	}	/**	 * 保存内容,注：允许其他应用往该文件写入内容	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void saveWriteable(String filename, String content) throws Exception{		FileOutputStream outStream = context.openFileOutput(filename, Context.MODE_WORLD_WRITEABLE);		outStream.write(content.getBytes());		outStream.close();	}	/**	 * 保存内容,注：允许其他应用对该文件读和写	 * @param filename 文件名称	 * @param content 文件内容	 * @throws Exception	 */	public void saveRW(String filename, String content) throws Exception{		FileOutputStream outStream = context.openFileOutput(filename, 				Context.MODE_WORLD_READABLE+ Context.MODE_WORLD_WRITEABLE);		outStream.write(content.getBytes());		outStream.close();	}	/**	 * 读取文件内容	 * @param filename 文件名称	 * @return	 * @throws Exception	 */	public String readFile(String filename) throws Exception{		FileInputStream inStream = context.openFileInput(filename);		byte[] buffer = new byte[1024];		int len = 0;		ByteArrayOutputStream outStream = new ByteArrayOutputStream();		while( (len = inStream.read(buffer))!= -1){			outStream.write(buffer, 0, len);		}		byte[] data = outStream.toByteArray();//得到文件的二进制数据		outStream.close();		inStream.close();		return new String(data);	}}

文件模式

FileServiceTest.java

package cn.itcast.file;import cn.itcast.service.FileService;import android.test.AndroidTestCase;import android.util.Log;public class FileServiceTest extends AndroidTestCase {	private static final String TAG = "FileServiceTest";	public void testSave() throws Throwable{		FileService service = new FileService(this.getContext());		service.save("itcast.txt", "www.itcast.cn");	}		public void testReadFile() throws Throwable{		FileService service = new FileService(this.getContext());		String result = service.readFile("www.txt");		Log.i(TAG, result);	}		public void testSaveAppend() throws Throwable{		FileService service = new FileService(this.getContext());		service.saveAppend("append.txt", ",www.csdn.cn");	}		public void testSaveReadable() throws Throwable{		FileService service = new FileService(this.getContext());		service.saveReadable("readable.txt", "www.sohu.com");	}		public void testSaveWriteable() throws Throwable{		FileService service = new FileService(this.getContext());		service.saveWriteable("writeable.txt", "www.sina.com.cn");	}		public void testSaveRW() throws Throwable{		FileService service = new FileService(this.getContext());		service.saveRW("rw.txt", "www.joyo.com");	}}

MainActivity.java

package cn.itcast.file;import cn.itcast.service.FileService;import android.app.Activity;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {	private static final String TAG = "MainActivity";    private FileService fileService;        @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);             fileService = new FileService(this);                Button button = (Button) this.findViewById(R.id.button);        button.setOnClickListener(new View.OnClickListener() {			@Override			public void onClick(View v) {				EditText filenameText = (EditText) findViewById(R.id.filename);				EditText contentText = (EditText) findViewById(R.id.filecontent);				String filename = filenameText.getText().toString();				String content = contentText.getText().toString();				try {					//判断sdcard是否存在于手机上，并且可以进行读写访问					if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){						fileService.saveToSDCard(filename, content);						Toast.makeText(MainActivity.this, R.string.success, 1).show();					}else{						Toast.makeText(MainActivity.this, R.string.sdcarderror, 1).show();					}				} catch (Exception e) {					Log.e(TAG, e.toString());					Toast.makeText(MainActivity.this, R.string.error, 1).show();				}			}		});    }}