import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import android.R.integer;import android.content.Context;import android.os.Environment;public class FileService {    private Context context;    public FileService(Context context) {        this.context = context;    }    public FileService() {    }    public String getFileFromSdcard(String fileName) {        FileInputStream inputStream = null;        // 缓存的流，和磁盘无关，不需要关闭        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();        File file = new File(Environment.getExternalStorageDirectory(),                fileName);        if (Environment.MEDIA_MOUNTED.equals(Environment                .getExternalStorageState())) {            try {                inputStream = new FileInputStream(file);                int len = 0;                byte[] data = new byte[1024];                while ((len = inputStream.read(data)) != -1) {                    outputStream.write(data, 0, len);                }            } catch (FileNotFoundException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } finally {                if (inputStream != null) {                    try {                        inputStream.close();                    } catch (IOException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }            }        }        return new String(outputStream.toByteArray());    }    /**     * @param fileName     *            文件的名称     * @param content     *            文件的内容     * @return     */    public boolean saveContentToSdcard(String fileName, String content) {        boolean flag = false;        FileOutputStream fileOutputStream = null;        // 获得sdcard卡所在的路径        File file = new File(Environment.getExternalStorageDirectory(),                fileName);        // 判断sdcard卡是否可用        if (Environment.MEDIA_MOUNTED.equals(Environment                .getExternalStorageState())) {            try {                fileOutputStream = new FileOutputStream(file);                fileOutputStream.write(content.getBytes());                flag = true;            } catch (FileNotFoundException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } finally {                if (fileOutputStream != null) {                    try {                        fileOutputStream.close();                    } catch (IOException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }            }        }        return flag;    }}

Manifest文件