AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.tes.textsd" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="16" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.tes.textsd.FileOperateActivity" 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> </manifest>

FileHelper.java /** * @Title: FileHelper.java * @Package com.tes.textsd * @Description: TODO(用一句话描述该文件做什么) * @author Alex.Z * @date 2013-2-26 下午5:45:40 * @version V1.0 */ package com.tes.textsd; import java.io.DataOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.FileWriter; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import android.content.Context; import android.os.Environment; public class FileHelper { private Context context; /** SD卡是否存在**/ private boolean hasSD = false; /** SD卡的路径**/ private String SDPATH; /** 当前程序包的路径**/ private String FILESPATH; public FileHelper(Context context) { this.context = context; hasSD = Environment.getExternalStorageState().equals( android.os.Environment.MEDIA_MOUNTED); SDPATH = Environment.getExternalStorageDirectory().getPath(); FILESPATH = this.context.getFilesDir().getPath(); } /** * 在SD卡上创建文件 * * @throws IOException */ public File createSDFile(String fileName) throws IOException { File file = new File(SDPATH + "//" + fileName); if (!file.exists()) { file.createNewFile(); } return file; } /** * 删除SD卡上的文件 * * @param fileName */ public boolean deleteSDFile(String fileName) { File file = new File(SDPATH + "//" + fileName); if (file == null || !file.exists() || file.isDirectory()) return false; return file.delete(); } /** * 写入内容到SD卡中的txt文本中 * str为内容 */ public void writeSDFile(String str,String fileName) { try { FileWriter fw = new FileWriter(SDPATH + "//" + fileName); File f = new File(SDPATH + "//" + fileName); fw.write(str); FileOutputStream os = new FileOutputStream(f); DataOutputStream out = new DataOutputStream(os); out.writeShort(2); out.writeUTF(""); System.out.println(out); fw.flush(); fw.close(); System.out.println(fw); } catch (Exception e) { } } /** * 读取SD卡中文本文件 * * @param fileName * @return */ public String readSDFile(String fileName) { StringBuffer sb = new StringBuffer(); File file = new File(SDPATH + "//" + fileName); try { FileInputStream fis = new FileInputStream(file); int c; while ((c = fis.read()) != -1) { sb.append((char) c); } fis.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return sb.toString(); } public String getFILESPATH() { return FILESPATH; } public String getSDPATH() { return SDPATH; } public boolean hasSD() { return hasSD; } }

main.xml <?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:id="@+id/hasSDTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="hello" /> <TextView android:id="@+id/SDPathTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="hello" /> <TextView android:id="@+id/FILESpathTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="hello" /> <TextView android:id="@+id/createFileTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="false" /> <TextView android:id="@+id/readFileTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="false" /> <TextView android:id="@+id/deleteFileTextView" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="false" /> </LinearLayout>

FileOperateActivity.class /** * @Title: FileOperateActivity.java * @Package com.tes.textsd * @Description: TODO(用一句话描述该文件做什么) * @author Alex.Z * @date 2013-2-26 下午5:47:28 * @version V1.0 */ package com.tes.textsd; import java.io.IOException; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class FileOperateActivity extends Activity { private TextView hasSDTextView; private TextView SDPathTextView; private TextView FILESpathTextView; private TextView createFileTextView; private TextView readFileTextView; private TextView deleteFileTextView; private FileHelper helper; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); hasSDTextView = (TextView) findViewById(R.id.hasSDTextView); SDPathTextView = (TextView) findViewById(R.id.SDPathTextView); FILESpathTextView = (TextView) findViewById(R.id.FILESpathTextView); createFileTextView = (TextView) findViewById(R.id.createFileTextView); readFileTextView = (TextView) findViewById(R.id.readFileTextView); deleteFileTextView = (TextView) findViewById(R.id.deleteFileTextView); helper = new FileHelper(getApplicationContext()); hasSDTextView.setText("SD卡是否存在:" + helper.hasSD()); SDPathTextView.setText("SD卡路径:" + helper.getSDPATH()); FILESpathTextView.setText("包路径:" + helper.getFILESPATH()); try { createFileTextView.setText("创建文件：" + helper.createSDFile("test.txt").getAbsolutePath()); } catch (IOException e) { e.printStackTrace(); } deleteFileTextView.setText("删除文件是否成功:" + helper.deleteSDFile("xx.txt")); helper.writeSDFile("1213212", "test.txt"); readFileTextView.setText("读取文件:" + helper.readSDFile("test.txt")); } }