基于TCP协议的Socket通信

上节中我们给大家接触了Socket的一些基本概念以及使用方法，相信大家对Socket已经有了初步的掌握。本节我们学习使用Socket来实现大文件的断点续传！在这里我们以他人的案例进行讲解，这是别人写好的一个Socket上传大文件的例子，不要求我们自己可以写出来，需要的时候会用就好！

1.运行效果图

1.先把我们编写好的Socket服务端运行起来

2.将一个音频文件放到SD卡根目录下

3.运行我们的客户端

4.上传成功后可以看到我们的服务端的项目下生成一个file的文件夹，我们可以在这里找到上传的文件：.log那个是我们的日志文件

2.实现流程图

3.代码示例：

先编写一个服务端和客户端都会用到的流解析类：

StreamTool.java：

public class StreamTool {public static void save(File file, byte[] data) throws Exception {FileOutputStream outStream = new FileOutputStream(file);outStream.write(data);outStream.close();}public static String readLine(PushbackInputStream in) throws IOException {char buf[] = new char[128];int room = buf.length;int offset = 0;int c;loop:       while (true) {switch (c = in.read()) {case -1:case '\\n':break loop;case '\\r':int c2 = in.read();if ((c2 != '\\n') && (c2 != -1)) in.unread(c2);break loop;default:if (--room < 0) {char[] lineBuffer = buf;buf = new char[offset + 128];room = buf.length - offset - 1;System.arraycopy(lineBuffer, 0, buf, 0, offset);}buf[offset++] = (char) c;break;}}if ((c == -1) && (offset == 0)) return null;return String.copyValueOf(buf, 0, offset);}/* 读取流* @param inStream* @return 字节数组* @throws Exception*/public static byte[] readStream(InputStream inStream) throws Exception{ByteArrayOutputStream outSteam = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = -1;while( (len=inStream.read(buffer)) != -1){outSteam.write(buffer, 0, len);}outSteam.close();inStream.close();return outSteam.toByteArray();}
} 

1）服务端的实现：

socket管理与多线程管理类：

FileServer.java：

public class FileServer {  private ExecutorService executorService;//线程池  private int port;//监听端口  private boolean quit = false;//退出  private ServerSocket server;  private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();//存放断点数据  public FileServer(int port){  this.port = port;  //创建线程池，池中具有(cpu个数*50)条线程  executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 50);  }  / * 退出 */  public void quit(){  this.quit = true;  try {  server.close();  } catch (IOException e) {  }  }  / * 启动服务 * @throws Exception */  public void start() throws Exception{  server = new ServerSocket(port);  while(!quit){  try {  Socket socket = server.accept();  //为支持多用户并发访问，采用线程池管理每一个用户的连接请求  executorService.execute(new SocketTask(socket));  } catch (Exception e) {  //  e.printStackTrace();  }  }  }  private final class SocketTask implements Runnable{  private Socket socket = null;  public SocketTask(Socket socket) {  this.socket = socket;  }  public void run() {  try {  System.out.println("accepted connection "+ socket.getInetAddress()+ ":"+ socket.getPort());  PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());  //得到客户端发来的第一行协议数据：Content-Length=143253434;filename=xxx.3gp;sourceid=  //如果用户初次上传文件，sourceid的值为空。  String head = StreamTool.readLine(inStream);  System.out.println(head);  if(head!=null){  //下面从协议数据中提取各项参数值  String[] items = head.split(";");  String filelength = items[0].substring(items[0].indexOf("=")+1);  String filename = items[1].substring(items[1].indexOf("=")+1);  String sourceid = items[2].substring(items[2].indexOf("=")+1);        long id = System.currentTimeMillis();//生产资源id，如果需要唯一性，可以采用UUID  FileLog log = null;  if(sourceid!=null && !"".equals(sourceid)){  id = Long.valueOf(sourceid);  log = find(id);//查找上传的文件是否存在上传记录  }  File file = null;  int position = 0;  if(log==null){//如果不存在上传记录,为文件添加跟踪记录  String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());  File dir = new File("file/"+ path);  if(!dir.exists()) dir.mkdirs();  file = new File(dir, filename);  if(file.exists()){//如果上传的文件发生重名，然后进行改名  filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));  file = new File(dir, filename);  }  save(id, file);  }else{// 如果存在上传记录,读取已经上传的数据长度  file = new File(log.getPath());//从上传记录中得到文件的路径  if(file.exists()){  File logFile = new File(file.getParentFile(), file.getName()+".log");  if(logFile.exists()){  Properties properties = new Properties();  properties.load(new FileInputStream(logFile));  position = Integer.valueOf(properties.getProperty("length"));//读取已经上传的数据长度  }  }  }  OutputStream outStream = socket.getOutputStream();  String response = "sourceid="+ id+ ";position="+ position+ "\\r\\n";  //服务器收到客户端的请求信息后，给客户端返回响应信息：sourceid=1274773833264;position=0  //sourceid由服务器端生成，唯一标识上传的文件，position指示客户端从文件的什么位置开始上传  outStream.write(response.getBytes());  RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");  if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));//设置文件长度  fileOutStream.seek(position);//指定从文件的特定位置开始写入数据  byte[] buffer = new byte[1024];  int len = -1;  int length = position;  while( (len=inStream.read(buffer)) != -1){//从输入流中读取数据写入到文件中  fileOutStream.write(buffer, 0, len);  length += len;  Properties properties = new Properties();  properties.put("length", String.valueOf(length));  FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));  properties.store(logFile, null);//实时记录已经接收的文件长度  logFile.close();  }  if(length==fileOutStream.length()) delete(id);  fileOutStream.close();                    inStream.close();  outStream.close();  file = null;  }  } catch (Exception e) {  e.printStackTrace();  }finally{  try {  if(socket!=null && !socket.isClosed()) socket.close();  } catch (IOException e) {}  }  }  }  public FileLog find(Long sourceid){  return datas.get(sourceid);  }  //保存上传记录  public void save(Long id, File saveFile){  //日后可以改成通过数据库存放  datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));  }  //当文件上传完毕，删除记录  public void delete(long sourceid){  if(datas.containsKey(sourceid)) datas.remove(sourceid);  }  private class FileLog{  private Long id;  private String path;  public Long getId() {  return id;  }  public void setId(Long id) {  this.id = id;  }  public String getPath() {  return path;  }  public void setPath(String path) {  this.path = path;  }  public FileLog(Long id, String path) {  this.id = id;  this.path = path;  }     }  }  

服务端界面类:ServerWindow.java：

public class ServerWindow extends Frame {private FileServer s = new FileServer(12345);private Label label;public ServerWindow(String title) {super(title);label = new Label();add(label, BorderLayout.PAGE_START);label.setText("服务器已经启动");this.addWindowListener(new WindowListener() {public void windowOpened(WindowEvent e) {new Thread(new Runnable() {public void run() {try {s.start();} catch (Exception e) {// e.printStackTrace();}}}).start();}public void windowIconified(WindowEvent e) {}public void windowDeiconified(WindowEvent e) {}public void windowDeactivated(WindowEvent e) {}public void windowClosing(WindowEvent e) {s.quit();System.exit(0);}public void windowClosed(WindowEvent e) {}public void windowActivated(WindowEvent e) {}});}/* @param args*/public static void main(String[] args) throws IOException {InetAddress address = InetAddress.getLocalHost();ServerWindow window = new ServerWindow("文件上传服务端：" + address.getHostAddress());window.setSize(400, 300);window.setVisible(true);}}

2）客户端(Android端)

首先是布局文件：activity_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"android:padding="5dp"><TextViewandroid:layout_width="fill_parent"android:layout_height="wrap_content"android:text="文件名"android:textSize="18sp" /><EditTextandroid:id="@+id/edit_fname"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="Nikki Jamal - Priceless.mp3" /><Buttonandroid:id="@+id/btn_upload"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="上传" /><Buttonandroid:id="@+id/btn_stop"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="停止" /><ProgressBarandroid:id="@+id/pgbar"style="@android:style/Widget.ProgressBar.Horizontal"android:layout_width="fill_parent"android:layout_height="40px" /><TextViewandroid:id="@+id/txt_result"android:layout_width="fill_parent"android:layout_height="wrap_content"android:gravity="center" />
</LinearLayout> 

因为断点续传，我们需要保存上传的进度，我们需要用到数据库，这里我们定义一个数据库管理类：DBOpenHelper.java：：

/* Created by Jay on 2015/9/17 0017.*/
public class DBOpenHelper extends SQLiteOpenHelper {public DBOpenHelper(Context context) {super(context, "jay.db", null, 1);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL("CREATE TABLE IF NOT EXISTS uploadlog (_id integer primary key autoincrement, path varchar(20), sourceid varchar(20))");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}
}

然后是数据库操作类：UploadHelper.java：

/* Created by Jay on 2015/9/17 0017.*/
public class UploadHelper {private DBOpenHelper dbOpenHelper;public UploadHelper(Context context) {dbOpenHelper = new DBOpenHelper(context);}public String getBindId(File file) {SQLiteDatabase db = dbOpenHelper.getReadableDatabase();Cursor cursor = db.rawQuery("select sourceid from uploadlog where path=?", new String[]{file.getAbsolutePath()});if (cursor.moveToFirst()) {return cursor.getString(0);}return null;}public void save(String sourceid, File file) {SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.execSQL("insert into uploadlog(path,sourceid) values(?,?)",new Object[]{file.getAbsolutePath(), sourceid});}public void delete(File file) {SQLiteDatabase db = dbOpenHelper.getWritableDatabase();db.execSQL("delete from uploadlog where path=?", new Object[]{file.getAbsolutePath()});}
}

对了，别忘了客户端也要贴上那个流解析类哦，最后就是我们的MainActivity.java了：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {private EditText edit_fname;private Button btn_upload;private Button btn_stop;private ProgressBar pgbar;private TextView txt_result;private UploadHelper upHelper;private boolean flag = true;private Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {pgbar.setProgress(msg.getData().getInt("length"));float num = (float) pgbar.getProgress() / (float) pgbar.getMax();int result = (int) (num * 100);txt_result.setText(result + "%");if (pgbar.getProgress() == pgbar.getMax()) {Toast.makeText(MainActivity.this, "上传成功", Toast.LENGTH_SHORT).show();}}};@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);bindViews();upHelper = new UploadHelper(this);}private void bindViews() {edit_fname = (EditText) findViewById(R.id.edit_fname);btn_upload = (Button) findViewById(R.id.btn_upload);btn_stop = (Button) findViewById(R.id.btn_stop);pgbar = (ProgressBar) findViewById(R.id.pgbar);txt_result = (TextView) findViewById(R.id.txt_result);btn_upload.setOnClickListener(this);btn_stop.setOnClickListener(this);}@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.btn_upload:String filename = edit_fname.getText().toString();flag = true;if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {File file = new File(Environment.getExternalStorageDirectory(), filename);if (file.exists()) {pgbar.setMax((int) file.length());uploadFile(file);} else {Toast.makeText(MainActivity.this, "文件并不存在~", Toast.LENGTH_SHORT).show();}} else {Toast.makeText(MainActivity.this, "SD卡不存在或者不可用", Toast.LENGTH_SHORT).show();}break;case R.id.btn_stop:flag = false;break;}}private void uploadFile(final File file) {new Thread(new Runnable() {public void run() {try {String sourceid = upHelper.getBindId(file);Socket socket = new Socket("172.16.2.54", 12345);OutputStream outStream = socket.getOutputStream();String head = "Content-Length=" + file.length() + ";filename=" + file.getName()+ ";sourceid=" + (sourceid != null ? sourceid : "") + "\\r\\n";outStream.write(head.getBytes());PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());String response = StreamTool.readLine(inStream);String[] items = response.split(";");String responseSourceid = items[0].substring(items[0].indexOf("=") + 1);String position = items[1].substring(items[1].indexOf("=") + 1);if (sourceid == null) {//如果是第一次上传文件，在数据库中不存在该文件所绑定的资源idupHelper.save(responseSourceid, file);}RandomAccessFile fileOutStream = new RandomAccessFile(file, "r");fileOutStream.seek(Integer.valueOf(position));byte[] buffer = new byte[1024];int len = -1;int length = Integer.valueOf(position);while (flag && (len = fileOutStream.read(buffer)) != -1) {outStream.write(buffer, 0, len);length += len;//累加已经上传的数据长度Message msg = new Message();msg.getData().putInt("length", length);handler.sendMessage(msg);}if (length == file.length()) upHelper.delete(file);fileOutStream.close();outStream.close();inStream.close();socket.close();} catch (Exception e) {Toast.makeText(MainActivity.this, "上传异常~", Toast.LENGTH_SHORT).show();}}}).start();}}

最后，还有，记得往AndroidManifest.xml中写入这些权限哦！

<!-- 在SDCard中创建与删除文件权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- 往SDCard写入数据权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<!-- 访问internet权限 -->
<uses-permission android:name="android.permission.INTERNET"/>