Initial

Author: elijuh

.gitignore

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+.idea/
+target/

README.md

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+How to include the API with Maven:
+```xml
+<repositories>
+    <repository>
+        <id>jitpack.io</id>
+        <url>https://jitpack.io</url>
+    </repository>
+</repositories>
+```
+```xml
+<dependencies>
+    <dependency>
+        <groupId>com.github.elijuh</groupId>
+        <artifactId>ServerPingerAPI</artifactId>
+        <version>1.0</version>
+    </dependency>
+</dependencies>
+```
+
+How to include the API with Gradle:
+```groovy
+repositories {
+    maven { url 'https://jitpack.io' }
+}
+dependencies {
+    compileOnly "com.github.elijuh:ServerPingerAPI:1.0"
+}
+```
+
+Example Usage of ServerPinger
+```java
+public class Test {
+    public static void main(String[] args) {
+        // Creating an instance
+        ServerPinger pinger = new ServerPinger();
+
+        try {
+            // Pinging hypixel.net server-list information
+            ServerResponse response = pinger.ping("hypixel.net");
+
+            // Ping in ms
+            long ping = response.getPing();
+
+            // Description of the server
+            ServerResponse.Description description = response.getDescription();
+
+            // Version of the server
+            ServerResponse.Version version = response.getVersion();
+
+            // Player information
+            ServerResponse.Players players = response.getPlayers();
+
+            int online = players.getOnline();
+            int maxPlayers = players.getMax();
+
+            // Some servers show a list of the players online, but in this example; hypixel does not.
+            List<ServerResponse.Player> playerList = players.getSample();
+
+            // You can also get the Base64 for the server icon
+            String iconBase = response.getFavicon();
+
+            // Displaying information to console
+            System.out.println("Ping: " + ping + "ms");
+            System.out.println("Description: " + description.getText());
+            System.out.println("Version: " + version.getName());
+            System.out.println("Player Count: " + online + "/" + maxPlayers);
+            System.out.println("Players: " + playerList);
+            System.out.println("Icon Base64: " + iconBase);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
+```

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.elijuh</groupId>
+    <artifactId>ServerPingerAPI</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <packaging>jar</packaging>
+    <name>ServerPingerAPI</name>
+
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <build>
+        <defaultGoal>clean install</defaultGoal>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.1</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <createDependencyReducedPom>false</createDependencyReducedPom>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>jitpack.io</id>
+            <url>https://jitpack.io/</url>
+        </repository>
+    </repositories>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.24</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>dnsjava</groupId>
+            <artifactId>dnsjava</artifactId>
+            <version>3.5.1</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.9.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>1.7.36</version>
+        </dependency>
+    </dependencies>
+
+</project>

src/main/java/com/elijuh/serverpinger/ServerPinger.java

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+package com.elijuh.serverpinger;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import lombok.Getter;
+import org.xbill.DNS.*;
+import org.xbill.DNS.Record;
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+
+@Getter
+public class ServerPinger {
+    private final Gson gson = new Gson();
+
+    public ServerResponse ping(String hostname) throws IOException {
+        return ping(ServerPingerOptions.builder().hostname(hostname).build());
+    }
+
+    public ServerResponse ping(ServerPingerOptions options) throws IOException {
+        if (options.getHostname() == null) {
+            throw new IllegalArgumentException("hostname cannot be null");
+        }
+
+        String hostname = options.getHostname();
+        int port = options.getPort();
+
+        try {
+            Record[] records = new Lookup(String.format("_minecraft._tcp.%s", hostname), Type.SRV).run();
+
+            if (records != null) {
+                for (Record record : records) {
+                    SRVRecord srv = (SRVRecord) record;
+
+                    hostname = srv.getTarget().toString().replaceFirst("\\.$", "");
+                    port = srv.getPort();
+                }
+
+            }
+        } catch (TextParseException e) {
+            e.printStackTrace();
+        }
+
+        String json;
+        long ping;
+
+        try (Socket socket = new Socket()) {
+            long start = System.currentTimeMillis();
+            socket.connect(new InetSocketAddress(hostname, port), options.getTimeout());
+            ping = System.currentTimeMillis() - start;
+
+            try (DataInputStream in = new DataInputStream(socket.getInputStream());
+                 DataOutputStream out = new DataOutputStream(socket.getOutputStream());
+                 ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+                 DataOutputStream handshake = new DataOutputStream(bytes)) {
+
+                handshake.writeByte(0x00);
+                Utils.writeVarInt(handshake, -1);
+                Utils.writeVarInt(handshake, options.getHostname().length());
+                handshake.writeBytes(options.getHostname());
+                handshake.writeShort(options.getPort());
+                Utils.writeVarInt(handshake, 1);
+
+                Utils.writeVarInt(out, bytes.size());
+                out.write(bytes.toByteArray());
+
+                out.writeByte(0x01);
+                out.writeByte(0x00);
+
+                Utils.readVarInt(in);
+                Utils.readVarInt(in);
+
+                int length = Utils.readVarInt(in);
+
+                byte[] data = new byte[length];
+                in.readFully(data);
+                json = new String(data, options.getCharset());
+
+                out.writeByte(0x09);
+                out.writeByte(0x01);
+                out.writeLong(System.currentTimeMillis());
+
+                Utils.readVarInt(in);
+                Utils.readVarInt(in);
+            }
+        }
+
+        JsonObject jsonObject = JsonParser.parseString(json).getAsJsonObject();
+        JsonElement descriptionJsonElement = jsonObject.get("description");
+
+        if (!descriptionJsonElement.isJsonObject()) {
+            String description = descriptionJsonElement.getAsString();
+            JsonObject descriptionJsonObject = new JsonObject();
+            descriptionJsonObject.addProperty("text", description);
+            jsonObject.add("description", descriptionJsonObject);
+
+        }
+
+        ServerResponse response = gson.fromJson(jsonObject, ServerResponse.class);
+        response.setPing(ping);
+
+        return response;
+    }
+}

src/main/java/com/elijuh/serverpinger/ServerPingerOptions.java

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+package com.elijuh.serverpinger;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Builder
+public class ServerPingerOptions {
+
+    @Getter
+    private String hostname;
+
+    @Getter
+    @Builder.Default
+    private String charset = "UTF-8";
+
+    @Getter
+    @Builder.Default
+    private int port = 25565;
+
+    @Getter
+    @Builder.Default
+    private int timeout = 5000;
+}

src/main/java/com/elijuh/serverpinger/ServerResponse.java

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+package com.elijuh.serverpinger;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+import lombok.ToString;
+
+import java.util.List;
+
+@Getter
+@ToString
+@RequiredArgsConstructor
+public class ServerResponse {
+    private final Description description;
+    private final Players players;
+    private final Version version;
+
+    @Setter
+    private String favicon;
+
+    @Setter
+    private long ping;
+
+    @Getter
+    @ToString
+    public static class Description {
+        private String text;
+    }
+
+    @Getter
+    @ToString
+    public static class Players {
+        private int max;
+        private int online;
+        private List<Player> sample;
+    }
+
+    @Getter
+    @ToString
+    public static class Player {
+        private String name;
+        private String id;
+    }
+
+    @Getter
+    @ToString
+    public static class Version {
+        private String name;
+        private int protocol;
+    }
+}

src/main/java/com/elijuh/serverpinger/Utils.java

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+package com.elijuh.serverpinger;
+
+import lombok.experimental.UtilityClass;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+@UtilityClass
+class Utils {
+    private static final int SEGMENT_BITS = 0x7F;
+    private static final int CONTINUE_BIT = 0x80;
+
+    public int readVarInt(DataInputStream in) throws IOException {
+        int value = 0, position = 0;
+        while (true) {
+            byte currentByte = in.readByte();
+            value |= (currentByte & SEGMENT_BITS) << position;
+
+            if ((currentByte & CONTINUE_BIT) == 0) break;
+
+            position += 7;
+
+            if (position >= 32) throw new RuntimeException("VarInt is too big");
+        }
+
+        return value;
+    }
+
+    public void writeVarInt(DataOutputStream out, int value) throws IOException {
+        while (true) {
+            if ((value & ~SEGMENT_BITS) == 0) {
+                out.writeByte(value);
+                return;
+            }
+
+            out.writeByte((value & SEGMENT_BITS) | CONTINUE_BIT);
+            value >>>= 7;
+        }
+    }
+}