From e22bd12e1275448034d9c6aa611b04f335c3f770 Mon Sep 17 00:00:00 2001
From: RockChin <1010553892@qq.com>
Date: Fri, 18 Jun 2021 10:59:07 +0800
Subject: [PATCH] Add support for LegacyPing(server ver 1.6.x)

---
 .../src/main/conn/MinecraftServer.java        | 148 ++++++++++++++++--
 .../src/test/conn/FakeServerTest.java         |  17 +-
 .../src/test/conn/LegacyPingTest.java         |  72 +++++++++
 .../src/test/conn/MinecraftServerTest.java    |   4 +-
 4 files changed, 215 insertions(+), 26 deletions(-)
 create mode 100644 BasicInfoAPI/src/test/conn/LegacyPingTest.java

diff --git a/BasicInfoAPI/src/main/conn/MinecraftServer.java b/BasicInfoAPI/src/main/conn/MinecraftServer.java
index 9c77a32..aa21479 100644
--- a/BasicInfoAPI/src/main/conn/MinecraftServer.java
+++ b/BasicInfoAPI/src/main/conn/MinecraftServer.java
@@ -6,9 +6,10 @@
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
-import java.io.IOException;
+import java.io.EOFException;
 import java.net.Socket;
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 
 /**
  * A MinecraftServer instance provides methods to create connection to server and communicate with peer.
@@ -35,18 +36,105 @@ public MinecraftServer(String host,int port)throws Exception {
                 .addShort(port)
                 .addVarInt(1).write(dataOutputStream);
         new PacketSend(0).write(dataOutputStream);
-        response=new Gson().fromJson(new PacketRecv(dataInputStream).popString(),Response.class);
-    }
+        try {
+            response = new Gson().fromJson(new PacketRecv(dataInputStream).popString(), Response.class);
+        }catch (EOFException e){//To change protocol.
+            System.out.println("ChangeProtocol");
+            socket=new Socket(host,port);
+            dataInputStream=new DataInputStream(socket.getInputStream());
+            dataOutputStream=new DataOutputStream(socket.getOutputStream());
 
+            dataOutputStream.write(0xFE);
+            dataOutputStream.write(0x01);
+            dataOutputStream.flush();
 
-    public class Response{
-        class description{
+            if (dataInputStream.readByte()==-1){
+                dataInputStream.readByte();
+                dataInputStream.readByte();
+                byte[] b=new byte[512];
+                dataInputStream.read(b);
+                ByteBase bbase=new ByteBase(b);
+                byte[] end=new byte[]{0,0};
+                if (new String(bbase.pop(end),StandardCharsets.UTF_16BE).equals("§1")){
+                    System.out.println("packingResponse.");
+                    response=new Response();
+                    response.version=new Response.version();
+                    response.version.protocol=Integer.parseInt
+                            (new String(bbase.pop(end),StandardCharsets.UTF_16BE));
+                    response.version.name=new String(bbase.pop(end),StandardCharsets.UTF_16BE);
+                    response.description=new Response.description();
+                    response.description.text=new String(bbase.pop(end),StandardCharsets.UTF_16BE);
+                    response.players=new Response.players();
+                    response.players.online=Integer.parseInt
+                            (new String(bbase.pop(end),StandardCharsets.UTF_16BE));
+                    response.players.max=Integer.parseInt
+                            (new String(bbase.pop(end),StandardCharsets.UTF_16BE));
+                }
+            }
+        }
+    }
+    private short len(String l){
+        String utf16be=new String(l.getBytes(StandardCharsets.UTF_8),StandardCharsets.UTF_16BE);
+        return (short)utf16be.length();
+    }
+    private void listByte(byte[] bytes){
+        System.out.print("list:");
+        for(byte b:bytes){
+            System.out.print(b+" ");
+        }
+        System.out.println();
+    }
+    private class ByteBase{
+        byte[] arr;
+        int index=0;
+        ByteBase(byte[] byteArr){
+            this.arr=byteArr;
+            for (byte b:byteArr){
+                System.out.print(b+" ");
+            }
+            System.out.println();
+            String s=new String(arr,StandardCharsets.UTF_16BE);
+            System.out.println(s);
+        }
+        public byte[] pop(byte[] end){
+            ArrayList<Byte> byteArrayList=new ArrayList<>();
+            byte[] b=new byte[2];
+            while(true){
+                b=pop(2);
+                if (b[0]==end[0]&&b[1]==end[1]){
+                    break;
+                }
+                byteArrayList.add(b[0]);
+                byteArrayList.add(b[1]);
+            }
+            int len=byteArrayList.size();
+            byte[] result=new byte[len];
+            for (int i=0;i<len;i++){
+                result[i]=byteArrayList.get(i);
+            }
+            listByte(result);
+            return result;
+        }
+        public byte pop(){
+            return arr[index++];
+        }
+        public byte[] pop(int len){
+            byte[] result=new byte[len];
+            for (int i=0;i<len;i++){
+                result[i]=pop();
+            }
+            return result;
+        }
+    }
+
+    public static class Response{
+        static class description{
             String text;
             String color;
             description[] extra;
         }
         description description;
-        class players{
+        static class players{
             int max;
             int online;
             class player{
@@ -56,7 +144,7 @@ class player{
             player[] sample;
         }
         players players;
-        class version{
+        static class version{
             String name;
             int protocol;
         }
@@ -67,27 +155,43 @@ class version{
 
     @Override
     public String getVersionName() {
-        return response.version.name;
+        if (response!=null&&response.version!=null) {
+            return response.version.name;
+        }else {
+            return null;
+        }
     }
 
     @Override
     public int getVersionProtocol() {
-        return response.version.protocol;
+        if (response!=null&&response.version!=null) {
+            return response.version.protocol;
+        }else {
+            return -1;
+        }
     }
 
     @Override
     public int getMaxPlayer() {
-        return response.players.max;
+        if (response!=null&&response.players!=null) {
+            return response.players.max;
+        }else {
+            return -1;
+        }
     }
 
     @Override
     public int getOnlinePlayer() {
-        return response.players.online;
+        if (response!=null&&response.players!=null) {
+            return response.players.online;
+        }else {
+            return -1;
+        }
     }
 
     @Override
     public Player[] getPlayerList() {
-        if (response.players.sample!=null) {
+        if (response!=null&&response.players!=null&&response.players.sample!=null) {
             int len = response.players.sample.length;
             Player[] players = new Player[len];
             for (int i = 0; i < len; i++) {
@@ -103,15 +207,23 @@ public Player[] getPlayerList() {
 
     @Override
     public String getDefaultDescriptionText() {
-        return response.description.text;
+        if (response!=null&&response.description!=null) {
+            return response.description.text;
+        }else {
+            return null;
+        }
     }
     @Override
     public String getDefaultDescriptionColor(){
-        return response.description.color;
+        if (response!=null&&response.description!=null) {
+            return response.description.color;
+        }else {
+            return null;
+        }
     }
     @Override
     public ExtraDescr[] getExtraDescription(){
-        if (response.description.extra!=null) {
+        if (response!=null&&response.description!=null&&response.description.extra!=null) {
             ExtraDescr[] extraDescrs = new ExtraDescr[response.description.extra.length];
             for (int i = 0; i < response.description.extra.length; i++) {
                 extraDescrs[i] = new ExtraDescr();
@@ -125,7 +237,11 @@ public ExtraDescr[] getExtraDescription(){
     }
     @Override
     public String getFavicon() {
-        return response.favicon;
+        if (response!=null) {
+            return response.favicon;
+        }else {
+            return null;
+        }
     }
 
 }
diff --git a/BasicInfoAPI/src/test/conn/FakeServerTest.java b/BasicInfoAPI/src/test/conn/FakeServerTest.java
index e770c85..0869968 100644
--- a/BasicInfoAPI/src/test/conn/FakeServerTest.java
+++ b/BasicInfoAPI/src/test/conn/FakeServerTest.java
@@ -8,7 +8,7 @@
 public class FakeServerTest {
     static DataInputStream dataInputStream;
     public static void main(String[] args)throws Exception {
-        ServerSocket socket=new ServerSocket(25565);
+        ServerSocket socket=new ServerSocket(25567);
         while (true){
             Socket client=socket.accept();
             System.out.println("newConn.");
@@ -16,19 +16,20 @@ public static void main(String[] args)throws Exception {
                 dataInputStream=new DataInputStream(client.getInputStream());
                 int len=0;
                 byte[] recv=new byte[2048];
-                System.out.println("Length(varInt):"+readVarInt());
-                System.out.println("PacketID(varInt):"+readVarInt());
-                System.out.println("ProtocolVersion(varInt):"+readVarInt());
-                System.out.println("ServerAddress(String):"+readString());
-                System.out.println("ServerPort(UnsignedShort):"+readUnsignedShort());
-                System.out.println("NextState(varIntEnum):"+readVarInt());
+//                System.out.println("Length(varInt):"+readVarInt());
+//                System.out.println("PacketID(varInt):"+readVarInt());
+//                System.out.println("ProtocolVersion(varInt):"+readVarInt());
+//                System.out.println("ServerAddress(String):"+readString());
+//                System.out.println("ServerPort(UnsignedShort):"+readUnsignedShort());
+//                System.out.println("NextState(varIntEnum):"+readVarInt());
                 while((len=dataInputStream.read(recv))!=-1){
                     if (len==0)
                         continue;
 //                    System.out.println("recv:"+new String(recv, StandardCharsets.UTF_8));
-                    for (int i=0;i<1024;i++){
+                    for (int i=0;i<len;i++){
                         System.out.print(recv[i]+" ");
                     }
+                    System.out.println();
                     recv=new byte[1024];
                 }
             }catch (Exception e){
diff --git a/BasicInfoAPI/src/test/conn/LegacyPingTest.java b/BasicInfoAPI/src/test/conn/LegacyPingTest.java
new file mode 100644
index 0000000..d61f0c8
--- /dev/null
+++ b/BasicInfoAPI/src/test/conn/LegacyPingTest.java
@@ -0,0 +1,72 @@
+package test.conn;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+
+public class LegacyPingTest {
+    public static void main(String[] args)throws Exception {
+        sendLegacyPing("localhost",25565);
+    }
+    public static void sendLegacyPing(String host,int port)throws Exception{
+
+        System.out.println("ChangeProtocol");
+        Socket socket=new Socket(host,port);
+        DataInputStream dataInputStream=new DataInputStream(socket.getInputStream());
+        DataOutputStream dataOutputStream=new DataOutputStream(socket.getOutputStream());
+//        dataOutputStream.write(0xFE);
+//        dataOutputStream.write(0x01);
+//        dataOutputStream.write(0xFA);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x0B);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x4D);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x43);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x7C);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x50);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x69);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x6E);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x67);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x48);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x6F);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x73);
+//        dataOutputStream.write(0x00);
+//        dataOutputStream.write(0x74);//MC|PingHost over
+//
+//        dataOutputStream.write(7+len(host));
+//        dataOutputStream.write(0x4A);
+//        dataOutputStream.write(len(host));
+//        String utf16beHost=new String(host.getBytes(StandardCharsets.UTF_8),StandardCharsets.UTF_16BE);
+//        dataOutputStream.write(utf16beHost.getBytes());
+//        dataOutputStream.write(port);
+//        dataOutputStream.flush();
+        dataOutputStream.write(0xFE);
+        dataOutputStream.write(0x01);
+        dataOutputStream.flush();
+
+        if (dataInputStream.readByte()==-1){
+            dataInputStream.readByte();
+            dataInputStream.readByte();
+            int len=0;
+            byte[] b=new byte[1024];
+            len=dataInputStream.read(b);
+            String s=new String(b,StandardCharsets.UTF_16BE);
+        }
+    }
+    private static short len(String l){
+        String utf16be=new String(l.getBytes(StandardCharsets.UTF_8),StandardCharsets.UTF_16BE);
+        return (short)utf16be.length();
+    }
+
+}
diff --git a/BasicInfoAPI/src/test/conn/MinecraftServerTest.java b/BasicInfoAPI/src/test/conn/MinecraftServerTest.java
index 395eebd..b1a0a8f 100644
--- a/BasicInfoAPI/src/test/conn/MinecraftServerTest.java
+++ b/BasicInfoAPI/src/test/conn/MinecraftServerTest.java
@@ -5,7 +5,7 @@
 
 public class MinecraftServerTest {
     public static void main(String[] args)throws Exception {
-        MinecraftServer minecraftServer=new MinecraftServer("cn-cd-dx-1.natfrp.cloud",18904);
+        MinecraftServer minecraftServer=new MinecraftServer("localhost",25565);
         System.out.println("version:name:"+minecraftServer.getVersionName()+" protocol:"+minecraftServer.getVersionProtocol());
         System.out.println("defaultDescription:color:"+minecraftServer.getDefaultDescriptionColor()+" text:"+minecraftServer.getDefaultDescriptionText());
         IServerInfo.ExtraDescr[] extraDescrs=minecraftServer.getExtraDescription();
@@ -19,4 +19,4 @@ public static void main(String[] args)throws Exception {
         }
         System.out.println("favicon:"+minecraftServer.getFavicon());
     }
-}
+}
\ No newline at end of file