TCP服务端开发为例--web开发不同url请求为何会走不同方法

拿java的web开发为例子，相信有很多小伙伴是做j2EE开发的，htpp请求，json数据传输都是工作中经常用的，查询请求，添加请求，修改请求前端配个url，例如https://localhost/intsmaze/user/add?name=intsmaze。然后后端建立一个controler类（类上配置url映射/user），然后创建一个addUser方法(在方法上配置映射/add)。然后启动web应用，前端发送的请求就会自动走到后端的addUser方法了。

但是你知道为什么这个请求走对应的方法吗？下面让我拿我大三期间基于TCP写的服务端程序做例子来看看背后的原理吧。这个程序时一个超市管理系统，客户端使用javaSwing编写，服务端使用javaSE编写，双方通信使用TCP协议，数据存储在mysql中。完整的项目上传在github上https://github.com/intsmaze/Swing-TCP-mysql。

服务端启动类，绑定端口。

public class LoginServer {        private int port=1000;private ServerSocket serversocket;private ExecutorService executorservice;private final int POOL_SIZE=1;//一个CPU线程池中工作线程的数目public LoginServer() throws Exception{    serversocket=new ServerSocket();serversocket.bind(new InetSocketAddress("127.0.0.1",port));    executorservice=Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()*POOL_SIZE);    //当前CPU数*1就是总线程池数目
    }public void service(){while(true){Socket socket=null;    try{socket=serversocket.accept();executorservice.execute(new Handler(socket));}catch(IOException e){e.printStackTrace();}}}    public static void main(String[] args) throws Exception {new LoginServer().service();                    }
}

路径映射方法

localhost/intsmaze/后面不同的路径就是截取对应的字符串然后调用对应的方法

public class Handler implements Runnable{public static final int SOLDERCONNECTION=0;//售货员登录public static final int MANAGERADDSOLDER=7;//管理员添加售货员public static final int MANAGERDELETESOLDER=8;//管理员删除售货员public static final int MANAGERMOIDFYSOLDER=9;//管理员修改售货员private Socket socket;    private BufferedReader bufIn=null;private BufferedWriter bufOut=null;        private Connection connection=null;    private PreparedStatement preparedstatement=null;private ResultSet resultset=null;public Handler(Socket socket) throws IOException{this.socket=socket;bufIn=new BufferedReader(new InputStreamReader(socket.getInputStream()));bufOut=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));    }        public void run() {try{                                                                String line=bufIn.readLine();//读取第一个选着功能    int i=Integer.valueOf(line);                switch(i)            {case SOLDERCONNECTION:solderConnection();//售货员登录0break;case MANAGERADDSOLDER:managerAddSolder();//管理员添加售货员7break;case MANAGERDELETESOLDER:managerDeleteSolder();//管理员删除售货员8break;case  MANAGERMOIDFYSOLDER:managerModifySolder();//管理员修改售货员9break;                }}catch(Exception e){socketUtil.close(socket);}}            public void solderConnection() throws Exception{String sr=null;    //读取账号和密码String arr[] =bufIn.readLine().split("#");;            connection=JdbcUtil.getConnection();preparedstatement=connection.prepareStatement("SELECT * FROM solder WHERE solder_number=? and solder_password=?");preparedstatement.setString(1,arr[0]);preparedstatement.setString(2,arr[1]);        resultset=preparedstatement.executeQuery();            if(resultset.next()){    bufOut.write("ok\n");//回馈查询信心
            bufOut.flush();                        sr=resultset.getInt(1)+"#"+resultset.getString(2)+"#"+resultset.getString(3)+"\n";bufOut.write(sr);bufOut.flush();            }else{bufOut.write("no");//回馈查询信心
                bufOut.flush();        }JdbcUtil.release(resultset, preparedstatement, connection);}    public void managerAddSolder() throws Exception{connection=JdbcUtil.getConnection();                String name=bufIn.readLine();    System.out.println(name);preparedstatement=connection.prepareStatement("insert into solder(solder_name) values(?) ");preparedstatement.setString(1,name);    preparedstatement.executeUpdate();//执行更新                            preparedstatement=connection.prepareStatement("select *from solder where solder_number=(select MAX(solder_number)from solder) ");resultset=preparedstatement.executeQuery();//执行更新        if(resultset.next()){bufOut.write("ok\n");//回馈查询信心
                bufOut.flush();String str=resultset.getString(1)+"#"+resultset.getString(2)+"#"+resultset.getString(3);bufOut.write(str+"\n");//回馈查询信心
                bufOut.flush();    }else{bufOut.write("no\n");//回馈查询信心
                bufOut.flush();}    JdbcUtil.release(resultset, preparedstatement, connection);}public void managerModifySolder() throws Exception{connection=JdbcUtil.getConnection();String arr[] = null;String line=null;String number=bufIn.readLine();preparedstatement=connection.prepareStatement("select *from solder  WHERE solder_number=? ");preparedstatement.setString(1,number);    resultset=preparedstatement.executeQuery();if(resultset.next()){bufOut.write("ok\n");//回馈查询信心
                bufOut.flush();    line=bufIn.readLine();arr=line.split("#");preparedstatement=connection.prepareStatement("update  solder set solder_password=?,solder_name=? WHERE solder_number=? ");preparedstatement.setString(1,arr[2]);    preparedstatement.setString(2,arr[1]);    preparedstatement.setString(3,arr[0]);    preparedstatement.executeUpdate();//执行更新
            }else{bufOut.write("no\n");//回馈查询信心
                bufOut.flush();                    }    socket.close();JdbcUtil.release(resultset, preparedstatement, connection);}public void managerDeleteSolder() throws Exception{connection=JdbcUtil.getConnection();        String number=bufIn.readLine();preparedstatement=connection.prepareStatement("select *from solder WHERE solder_number=? ");preparedstatement.setString(1,number);    resultset=preparedstatement.executeQuery();if(resultset.next()){bufOut.write("ok\n");//回馈查询信心
                bufOut.flush();                        preparedstatement=connection.prepareStatement("delete from solder  WHERE solder_number=? ");preparedstatement.setString(1,number);    preparedstatement.executeUpdate();//执行更新
            }else{bufOut.write("no\n");//回馈查询信心
                bufOut.flush();    }    socket.close();JdbcUtil.release(resultset, preparedstatement, connection);}}

以localhost/intsmaze/user/add?name=intsmaze的url来反向剖析tcp服务端如何接收，并调用对应方法。localhost是与服务器建立连接，然后发送intsmaze/user/add?name=intsmaze为一个数据到服务器，服务器接收到该字符串后，根据/截取，然后判断该请求是发给intsmaze的应用。然后通过user知道这个请求时user模块（用户管理模块），然后通过add知道是调用添加用户方法。?后面就是对于的参数获取存入数据库即可.

对上面的方法改进如下即可实现

                String line=bufIn.readLine();//读取第一个选着功能  line的值为intsmaze/user/add?name=intsmaze  String arr[]=line.split("/");String model=arr[1];String method=arr[2].split("?")[0];String param=arr[2].split("?")[1];if(model.endsWith("user")){if(method.equals("add")){user.add(param);}}else if(model.equals("goods")){...}else if...

转载于:https://www.cnblogs.com/intsmaze/p/8098173.html