feat: add test code of 1 million tcp connection

tests/network/test02/java/Server.java

@@ -0,0 +1,41 @@
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.InetSocketAddress;
+ 
+public class Server {
+    public static final int MAX_CONNECTION_NUM = 1100000;
+
+    public static void main(String[] args) {
+        if(2 != args.length){
+            System.out.println("Usage: java Server <server ip> <server port>\n");
+            return;
+        }
+
+        String sIp = args[0];
+        int sPort = Integer.parseInt(args[1]);
+
+        //用数组将 socket 保存起来，防止连接被过早回收
+        Socket[] sockets = new Socket[MAX_CONNECTION_NUM];
+
+        try {
+            ServerSocket ss = new ServerSocket();
+            ss.bind(new InetSocketAddress(sIp, sPort));
+            System.out.println("启动Server " + sIp + ":" + sPort + "...");
+
+            int i = 0;
+            while(true){
+                try{
+                    Socket s = ss.accept();
+                    sockets[i] = s;
+                    i++;
+                    System.out.println("Server " + sIp + ":" + sPort + " 接收到第 " + i +" 条连接！");
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}