Android文件操作

<?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" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/fileName" />

    <EditText
        android:id="@+id/txtName"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint=""
        android:maxLines="1" />

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/fileContext" />

    <EditText
        android:id="@+id/txtContext"
        android:layout_width="fill_parent"
        android:layout_height="100dp"
        android:gravity="left"
        android:hint=""
        android:minLines="4" />

    <Button
        android: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;

    @Override
    protected 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 {

        @Override
        public 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();
    }
}