保存读取文件

// 保存文件
		OnClickListener save_listener = new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if (et_input.getText().toString().equals("")) {
					Toast.makeText(context, "请输入文本!", 1000).show();
					return;
				}
				switch (v.getId()) {
				case R.id.In_save:
					FileOutputStream fos = null;
					try {
						fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);// 以私有模式创建文件
						String text = et_input.getText().toString();
						fos.write(text.getBytes());// 写入数据
						fos.flush(); // 将缓冲区剩余数据写入文件
						fos.close(); // 关闭FileOutputStream
						Toast.makeText(context, "保存文件成功", 1000).show();
					} catch (FileNotFoundException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} finally {
						if (fos != null) {
							try {
								fos.close();
							} catch (IOException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
					}
					break;

				case R.id.In_save_sd:
					if (Environment.getExternalStorageState().equals(
							android.os.Environment.MEDIA_MOUNTED)) {
						FileOutputStream ostream = null;
						try {
							//*
							File myfile = new File(Environment
									.getExternalStorageDirectory().getPath(),
									FILENAME);
							Log.i("In_save_sd",Environment
									.getExternalStorageDirectory().getPath());
							/*
							if (!myfile.exists()) {
								myfile.createNewFile();
							}
							*/
							if (myfile.exists()) {
								myfile.delete();
							}
							myfile.createNewFile();
							//*/
							/*
						FileOutputStream fos = null;
						fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);// 以私有模式创建文件
						String text = et_input.getText().toString();
						fos.write(text.getBytes());// 写入数据
						fos.flush(); // 将缓冲区剩余数据写入文件
						fos.close(); // 关闭FileOutputStream
						Toast.makeText(context, "保存文件成功", 1000).show();
							 * */
							/*
							ostream = openFileOutput(Environment
									.getExternalStorageDirectory().getPath()+FILENAME, 
									Context.MODE_WORLD_WRITEABLE);// 以私有模式创建文件
							*/
							ostream = new FileOutputStream(myfile, true);
							String text = et_input.getText().toString();
							ostream.write(text.getBytes());
							//
							//ostream.flush(); // 将缓冲区剩余数据写入文件
							//ostream.close(); // 关闭FileOutputStream							
							//
							Toast.makeText(context, "保存文件到sd卡成功", 1000).show();
						} catch (FileNotFoundException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						} catch (IOException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						} finally {
							if (ostream != null) {
								try {
									ostream.close();
								} catch (IOException e) {
									// TODO Auto-generated catch block
									e.printStackTrace();
								}
							}
						}
					}
					break;

				default:
					break;
				}
			}
		};
		btn_save.setOnClickListener(save_listener);
		btn_save_sd.setOnClickListener(save_listener);

		// 读取
		OnClickListener output_listener = new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				FileInputStream inStream = null;
				ByteArrayOutputStream stream = null;
				try {
					switch (v.getId()) {
					case R.id.out_put:
						inStream = openFileInput(FILENAME);
						break;
					case R.id.out_put_sd:
						if (Environment.getExternalStorageState().equals(
								android.os.Environment.MEDIA_MOUNTED)) {
							File sd_file = new File(Environment
									.getExternalStorageDirectory().getPath(),
									FILENAME);
							Log.i("out_put_sd",Environment
									.getExternalStorageDirectory().getPath());
							if (!sd_file.exists()) {
								Toast.makeText(context, "未找到该文件", 1000).show();
								return;
							}
							inStream = new FileInputStream(sd_file);
						}
					default:
						break;
					}
					stream = new ByteArrayOutputStream();
					byte[] buffer = new byte[1024];
					int length = -1;
					while ((length = inStream.read(buffer)) != -1) {
						stream.write(buffer, 0, length);
					}
					stream.close();
					inStream.close();
					et_output.setText(stream.toString());
					Toast.makeText(context, "获取文本成功!", 1000).show();
				} catch (FileNotFoundException e) {
					e.printStackTrace();
					Toast.makeText(context, "文件未找到", 1000).show();
					System.out.println(e.toString());
				} catch (IOException e) {
					System.out.println(e.toString());
					return;
				} finally {
					try {
						if (stream != null)
							stream.close();
						if (inStream != null)
							inStream.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}
		};
		btn_out.setOnClickListener(output_listener);
		btn_out_sd.setOnClickListener(output_listener);