对于普通应用的网络模块一般使用http文本协议，在android开发中使用http协议比较简单，sdk已经做了很好的封装了，具体使用方法可以参考我的这篇博文。而在游戏开发中，可以结合使用http和socket，当然了http协议底层也是基于tcp协议的。http协议是无连接、无状态的，每次连接只能处理一个请求，然后就断了，而且发一个请求需要附加额外信息(请求行、请求头),每次请求都需要重新建立连接；使用socket的好处是更高效和省流量，建立一次连接后，只要不手动或者出现异常断开，就可以一直互相发送数据，而且是直接以字节的形式发送，不需要额外的附加信息，缺点就是难度加大了，需要服务端和客户端很好的配合，保证发送和读取时数据的顺序一致。本文通过一个简单的demo介绍开发android网游时socket的使用方法，主要包括：android客户端和一个简单的使用java实现的server端，实现客户端和服务端互相发送数据的功能。
1.客户端代码实现
首先创建一个Android应用，名称:AndroidSocketTest
然后分别创建4个文件：BytesUtil.java、BytesReader.java、BytesWriter.java、TCPCommunication.java,下面分别介绍这几个文件的用处和源码：
BytesUtil.java：包含了一些静态工具方法：基本类型和字节数组的相互转换，字符串和字节数组的相互转换，字节数组的赋值和大小重置，对输入流进行读取保存等。比较简单，下面直接看源码：
/**author:alexzhou email :[email protected]date :2012-11-7 **/ public final class BytesUtil { /** *整型转换成字节数组 * @param value 要转换的整型值 * @return */ public static byte[] shortToBytes(int value) { byte []write = new byte[2]; write[0] = (byte)( (value >>> 8) & 0xFF); write[1] = (byte)( (value >>> 0) & 0xFF); return write; } public static byte[] intToBytes(int value) { byte []write = new byte[4]; write[0] = (byte)( (value >>> 24) & 0xFF); write[1] = (byte)( (value >>> 16) & 0xFF); write[2] = (byte)( (value >>> 8) & 0xFF); write[3] = (byte)( (value >>> 0) & 0xFF); return write; } public static byte[] longToBytes(long value) { byte []write = new byte[8]; write[0] = (byte)( (value >>> 56) & 0xFF); write[1] = (byte)( (value >>> 48) & 0xFF); write[2] = (byte)( (value >>> 40) & 0xFF); write[3] = (byte)( (value >>> 32) & 0xFF); write[4] = (byte)( (value >>> 24) & 0xFF); write[5] = (byte)( (value >>> 16) & 0xFF); write[6] = (byte)( (value >>> 8) & 0xFF); write[7] = (byte)( (value >>> 0) & 0xFF); return write; } /** * 字节数组转换成整型 * @param value * @return */ public static int bytesToInt(byte []value) { int i1 = (value[0] & 0xFF) << 24; int i2 = (value[1] & 0xFF) << 16; int i3 = (value[2] & 0xFF) << 8; int i4 = (value[3] & 0xFF) << 0; return (i1 | i2 | i3 | i4); } public static short bytesToShort(byte[] value) { int s1 = (value[0] & 0xFF) << 8; int s2 = (value[1] & 0xFF) << 0; return (short)(s1 | s2); } public static long bytesToLong(byte[] value) { long L1 = (value[0] & 0xFF) << 56; long L2 = (value[1] & 0xFF) << 48; long L3 = (value[2] & 0xFF) << 40; long L4 = (value[3] & 0xFF) << 32; long L5 = (value[4] & 0xFF) << 24; long L6 = (value[5] & 0xFF) << 16; long L7 = (value[6] & 0xFF) << 8; long L8 = (value[7] & 0xFF) << 0; return (L1 | L2 | L3 | L4 | L5 | L6 | L7 | L8); } /** * 从指定字节数组中拷贝部分数据 * @param origin * @param from * @param to * @return */ public static byte[] copyBytes(byte[] origin,int from,int to) { int len = to - from; if(len < 0 || origin.length - from <= 0) { throw new IllegalArgumentException("copyBytes->error arguments:to="+to+",from="+from); } byte[] ret = new byte[len]; if(len == 0) return ret; System.arraycopy(origin, from, ret, 0, Math.min(len, origin.length - from)); return ret; } /** * 重置字节数组的大小，然后把原内容复制到新的字节数组中 * @param origin * @param newSize * @return */ public static byte[] resizeBytes(byte[] origin,int newSize) { if(newSize < 0) { throw new IllegalArgumentException("resizeBytes->newSize must >= 0"); } byte[] ret = new byte[newSize]; if(newSize == 0) return ret; System.arraycopy(origin,0,ret,0,Math.min(origin.length, newSize)); return ret; } /** * 读取输入流中字节,并保存到指定的字节数组中 * @param is * @param data * @param off * @param len */ public static void readData(InputStream is, byte data[], int off, int len) { int hasRead = 0; final int BUFFER = 1024; while(hasRead < len) { try { int remain = len - hasRead; int count = is.read(data, off + hasRead, remain > BUFFER ? BUFFER : remain); if(count < 0) throw new IOException("readData->read data error"); hasRead += count; } catch (IOException e) { e.printStackTrace(); } } }}BytesReader.java：从服务端接收数据时使用，定义了一个字节数组类型的成员变量，用来保存从输入流中读取的数据。封装了一些从该字节数组中读取相应数据类型的函数，源码如下：
/** * 接受服务端数据时，读取字节并转换到相应类型author:alexzhou email :[email protected]date :2012-11-7 **/ public final class BytesReader { private final byte []data; //字节数组的大小 private final int size; //当前读取的位置 private int position; public BytesReader(byte []data) { this.data = data; this.size = data.length; this.position = 0; } public byte[] read(int len) { if(len < 0) return null; byte[] value = BytesUtil.copyBytes(data, position, position + len); this.position += len; return value; } public int getSize() { return size; } public boolean isAvailable() { return size - position > 0; } public short readShort() { byte[] value = read(2); return BytesUtil.bytesToShort(value); } public int readInt() { byte[] value = read(4); return BytesUtil.bytesToInt(value); } public long readLong() { byte[] value = read(8); return BytesUtil.bytesToLong(value); } public byte readByte() { int value = this.isAvailable() ? (0xFF & data[position++]) : -1; return (byte)value; } public byte[] readBytes() { int len = readShort(); //读取大数据 if(len >= 0xFFFF) { len = this.readInt(); } return len == 0 ? null : read(len); } public String readUTF() { byte[] bytes = readBytes(); if(null != bytes) { try { return new String(bytes,"UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } return null; }}
BytesWriter.java：向服务端发送数据时使用，跟BytesReader.java对应，也是把需要发送的数据保存到字节数组中，然后一次性发送给服务器。源码如下：
/**author:alexzhou email :[email protected]date :2012-11-9 **/ public final class BytesWriter { private byte[] data; private int count; public BytesWriter() { this(64); } public BytesWriter(int size) { this.data = new byte[size]; } public byte[] getBytes() { return this.data.length == count ? data : count == 0 ? null : BytesUtil.resizeBytes(this.data, count); } public void write(byte[] value) { this.write(value, 0, value == null ? 0 : value.length); } public void write(byte[] d, int offset, int len) { if(d == null || len == 0) return; int newCount = count + len; if(newCount > this.data.length) { int newSize = Math.max(this.data.length << 1, newCount); this.data = BytesUtil.resizeBytes(this.data, newSize); } System.arraycopy(d, offset, this.data, this.count, len); this.count = newCount; } public void writeInt(int value) { this.write(BytesUtil.intToBytes(value)); } public void writeShort(int value) { this.write(BytesUtil.shortToBytes(value)); } public void writeLong(long value) { this.write(BytesUtil.longToBytes(value)); } public void writeByte(byte value) { int newCount = count + 1; if(newCount > this.data.length) { int newSize = Math.max(this.data.length << 1, newCount); this.data = BytesUtil.resizeBytes(this.data, newSize); } this.data[count] = value; this.count = newCount; } public void writeBytes(byte[] value) { int length = (value == null ? 0 : value.length); //发送大数据时 if(length >= 0xFFFF) { this.writeShort(0xFFFF); this.writeInt(length); }else { //告诉服务端发送的数据的大小 this.writeShort(length); } this.write(value); } public void writeUTF(String value) { if(value == null || value.length() == 0) { this.writeShort(0); } byte[] bytes = null; try { bytes = value.getBytes("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } this.writeBytes(bytes); } }
TCPCommunication.java：上面的三个类都是辅助工具类，是给它使用的，它负责socket的创建和连接服务器、读取和发送数据，以及通过Handler发送消息给UI线程更新界面显示数据。由于我们的目的是使用socket通信，所以去掉了很多代码，这里只是简单的建立一次连接，发送和接收完数据后就关闭连接了。源码如下：
public class TCPCommunication implements Runnable { private Socket mSocket; private DataInputStream mDis; private DataOutputStream mDos; private Handler mHandler; private volatile boolean isRunning = false; public TCPCommunication(Handler handler) { this.mHandler = handler; } public boolean isRunning() { return isRunning; } public void startWork() { Thread t = new Thread(this); t.setPriority(Thread.MAX_PRIORITY); t.start(); } public void stopWork() { this.isRunning = false; } @Override public void run() { try { mSocket = new Socket("10.0.2.2",8888); mDis = new DataInputStream(mSocket.getInputStream()); mDos = new DataOutputStream(mSocket.getOutputStream()); //开始发送数据到服务端 BytesWriter bw = new BytesWriter(); String username = "alexzhou"; String password = "123456"; int flag1 = 12345; short flag2 = 12; long flag3 = 100000000L; bw.writeUTF(username); bw.writeUTF(password); bw.writeInt(flag1); bw.writeShort(flag2); bw.writeLong(flag3); byte[] data = bw.getBytes(); BytesWriter out = null; if(data.length >= 0xFFFF) { out = new BytesWriter(data.length + 6); out.writeShort(0xFFFF); out.writeInt(data.length); }else{ out = new BytesWriter(data.length + 2); out.writeShort(data.length); } out.write(data); mDos.write(out.getBytes()); //开始从服务端接收数据 int len = mDis.readShort(); if(len == 0xFFFF) { len = mDis.readInt(); } byte[] inputData = new byte[len]; BytesUtil.readData(mDis, inputData, 0, len); BytesReader br = new BytesReader(inputData); String user_id = br.readUTF(); String recv_username = br.readUTF(); String nickname = br.readUTF(); int i = br.readInt(); short s = br.readShort(); long l = br.readLong(); String result = "登录成功~您的信息如下\n id:"+user_id + "\n用户名:" + recv_username + "\n昵称:" + nickname + "\n 序列号:" + i + "-" + s + "-" + l; Message msg = mHandler.obtainMessage(); msg.what = 0; msg.obj = result; mHandler.sendMessage(msg); mDis.close(); mDos.close(); mSocket.close(); } catch (UnknownHostException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } }; }MainActivty.java的代码比较简单，源码：
public class MainActivity extends Activity { private TextView mTextView; private Button mButton; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mTextView = (TextView)this.findViewById(R.id.text); mButton = (Button)this.findViewById(R.id.button_send); mButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { new TCPCommunication(mHandler).startWork(); } }); } private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { String result = (String)msg.obj; mTextView.setText(result); } }; @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; }}到此为止，Android客户端的代码已经全部完成了，记得给应用添加访问网络的权限哦：在配置文件中添加
<uses-permission android:name="android.permission.INTERNET" />
2.服务端代码实现
服务端的代码比较简单，当然了，一般在实际的开发中，服务端和客户端不是同一个人写的，这里我就把客户端里的那几个工具类拿来直接用了。
创建一个java项目，然后把BytesReader.java、BytesWriter.java、BytesUtil.java三个文件拷贝到项目的包下，然后创建Server.java，功能比较简单，监听8888端口，然后等待客户端连接，接收和发送数据。源码如下：
/**author:alexzhou email :[email protected]date :2012-11-7 **/ public final class Server implements Runnable{ private ServerSocket mServerSocket; private Socket mClient; private DataInputStream mDis; private DataOutputStream mDos; private boolean isRunning = false; public void start() { this.isRunning = true; Thread t = new Thread(this); t.start(); } public void stop() { this.isRunning = false; } public static void main(String []args) { new Server().start(); } @Override public void run() { try { mServerSocket = new ServerSocket(8888); System.out.println("start server"); while(isRunning) { System.out.println("wait client connect!!"); mClient = mServerSocket.accept(); //接收客户端发送的数据 mDis = new DataInputStream(mClient.getInputStream()); //数据的长度 int len = mDis.readShort(); if(len == 0xFFFF) { len = mDis.readInt(); } System.out.println("client data size:" + len); byte[] inputData = new byte[len]; BytesUtil.readData(mDis, inputData, 0, len); BytesReader br = new BytesReader(inputData); String username = br.readUTF(); String password = br.readUTF(); int i = br.readInt(); short s = br.readShort(); long l = br.readLong(); System.out.println("username:"+username+";password="+password+"Long="+l); //向客户端发送数据 mDos = new DataOutputStream(mClient.getOutputStream()); BytesWriter bw = new BytesWriter(32); String user_id = "123456"; String nickname = "周江海"; bw.writeUTF(user_id); bw.writeUTF(username); bw.writeUTF(nickname); bw.writeInt(i); bw.writeShort(s); bw.writeLong(l); byte[] data = bw.getBytes(); BytesWriter out = null; if(data.length >= 0xFFFF) { out = new BytesWriter(data.length + 6); out.writeShort(0xFFFF); out.writeInt(data.length); }else { out = new BytesWriter(data.length + 2); out.writeShort(data.length); } out.write(data); mDos.write(out.getBytes()); mDos.close(); mDis.close(); mClient.close(); } } catch (IOException e) { e.printStackTrace(); } }}
现在验证一下，先启动Server，然后运行Android客户端应用，屏幕中间会出现TextView和一个button，TextView的内容是HelloWorld，点击button就会发送登陆信息给服务端，然后服务端返回数据显示到TextView上。下面分别是服务端的打印消息和客户端的显示截图。
主要需要掌握基本数据类型和字符串跟字节数组的转换，然后按照指定的顺序发送。最重要的是要注意客户端和服务端从字节数组读取和往字节数组写入数据时的顺序要对应。
下面是源码链接：http://download.csdn.net/detail/zhoujianghai/4751981
转载请注明来自：Alex Zhou的程序世界，本文链接：http://codingnow.cn/android/884.html