<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical" ><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/fileName" /><EditTextandroid:id="@+id/txtName"android:layout_width="fill_parent"android:layout_height="wrap_content"android:hint=""android:maxLines="1" /><TextViewandroid:layout_width="fill_parent"android:layout_height="wrap_content"android:text="@string/fileContext" /><EditTextandroid:id="@+id/txtContext"android:layout_width="fill_parent"android:layout_height="100dp"android:gravity="left"android:hint=""android:minLines="4" /><Buttonandroid:id="@+id/btnSave"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="@string/btnSave" /></LinearLayout>

package apk.example.androidapk;import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.app.Activity;
import apk.example.service.FileServer;public class MainActivity extends Activity {public Button btnSave;public EditText txtName, txtContext;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);txtName = (EditText) findViewById(R.id.txtName);txtContext = (EditText) findViewById(R.id.txtContext);btnSave = (Button) findViewById(R.id.btnSave);btnSave.setOnClickListener(new BtnSaveListener());}private final class BtnSaveListener implements View.OnClickListener {@Overridepublic void onClick(View v) {String fileName = txtName.getText().toString();String fileContext = txtContext.getText().toString();FileServer server = new FileServer(getApplicationContext());try {if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {server.saveToSDCard(fileName, fileContext);// 保存成功
                    Toast.makeText(getApplicationContext(), R.string.success,Toast.LENGTH_LONG).show();} else {// SDCard不存在或者写保护
                    Toast.makeText(getApplicationContext(),R.string.sdCardMessage, Toast.LENGTH_LONG).show();}} catch (Exception e) {// 保存失败
                Toast.makeText(getApplicationContext(), R.string.fail,Toast.LENGTH_LONG).show();e.printStackTrace();}}}
}

package apk.example.service;import java.io.File;
import java.io.FileOutputStream;import android.content.Context;
import android.os.Environment;public class FileServer {private Context context;public FileServer(Context context) {this.context = context;}/*** * @param 文件名称* @param 文件内容* @throws 异常信息*/public void save(String fileName, String fileContext) throws Exception {// 私有操作模式：创建出来的文件只能被本应用访问，其它应用无法访问该文件，另外采用私有操作模式创建的文件，写入文件中的内容会覆盖原文件的内容FileOutputStream outStream = context.openFileOutput(fileName,Context.MODE_PRIVATE);outStream.write(fileContext.getBytes());outStream.close();}/*** * @param 文件名称* @param 文件内容* @throws 异常信息*/public void saveToSDCard(String fileName, String context) throws Exception {// 私有操作模式：创建出来的文件只能被本应用访问，其它应用无法访问该文件，另外采用私有操作模式创建的文件，写入文件中的内容会覆盖原文件的内容File file = new File(Environment.getExternalStorageDirectory(),fileName);FileOutputStream outStream = new FileOutputStream(file);outStream.write(context.getBytes());outStream.close();}
}