feat: coordination recipes example

coordination/pom.xml

@@ -0,0 +1,20 @@
+<?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>
+    <parent>
+        <groupId>tech.ydb.examples</groupId>
+        <artifactId>ydb-sdk-examples</artifactId>
+        <version>1.1.0-SNAPSHOT</version>
+    </parent>
+
+    <groupId>tech.ydb.coordination.examples</groupId>
+    <artifactId>ydb-coordination-examples</artifactId>
+
+    <name>YDB SDK Coordination Service examples</name>
+
+    <packaging>pom</packaging>
+
+    <modules>
+        <module>recipes</module>
+    </modules>
+</project>

coordination/recipes/pom.xml

@@ -0,0 +1,58 @@
+<?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>
+
+    <parent>
+        <groupId>tech.ydb.coordination.examples</groupId>
+        <artifactId>ydb-coordination-examples</artifactId>
+        <version>1.1.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>ydb-coordination-recipes-example</artifactId>
+    <name>YDB Coordination Service recipes example</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-slf4j-impl</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>tech.ydb</groupId>
+            <artifactId>ydb-sdk-coordination</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>tech.ydb.auth</groupId>
+            <artifactId>yc-auth-provider</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>jdbc-coordination-recipes-example</finalName>
+        <plugins>
+            <!-- copy dependencies to libs folder -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+            </plugin>
+            <!-- add libs folder to classpath -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <classpathPrefix>libs/</classpathPrefix>
+                            <mainClass>tech.ydb.coordination.recipes.example.Main</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

coordination/recipes/src/main/java/tech/ydb/coordination/recipes/example/LockApp.java

@@ -0,0 +1,88 @@
+package tech.ydb.coordination.recipes.example;
+
+import tech.ydb.coordination.CoordinationClient;
+import tech.ydb.coordination.recipes.example.lib.locks.InterProcessLock;
+import tech.ydb.coordination.recipes.example.lib.locks.InterProcessMutex;
+
+import java.time.Duration;
+import java.util.Scanner;
+
+public class LockApp {
+
+    InterProcessLock lock;
+
+    LockApp(CoordinationClient client) {
+        client.createNode("examples/app").join().expectSuccess("cannot create coordination path");
+        lock = new InterProcessMutex(
+                client,
+                "examples/app",
+                "data".getBytes(),
+                "default_lock"
+        );
+    }
+
+    public void lock(Duration duration) {
+        try {
+            if (duration == null) {
+                lock.acquire();
+            } else {
+                lock.acquire(duration);
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void release() {
+        try {
+            lock.release();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    private boolean isAcquired() {
+        return lock.isAcquiredInThisProcess();
+    }
+
+    public void run() {
+        Scanner scanner = new Scanner(System.in);
+        System.out.println("Enter commands: lock [seconds] | release | reconnect | ?");
+
+        while (scanner.hasNextLine()) {
+            String commandLine = scanner.nextLine().trim();
+            String[] commandParts = commandLine.split("\\s+");
+            String command = commandParts[0];
+
+            switch (command.toLowerCase()) {
+                case "lock":
+                    int seconds = -1;
+                    if (commandParts.length > 1) {
+                        try {
+                            seconds = Integer.parseInt(commandParts[1]);
+                        } catch (NumberFormatException e) {
+                            System.out.println("Invalid number format, defaulting to 0 seconds");
+                        }
+                    }
+                    if (seconds == -1) {
+                        lock(null);
+                    } else {
+                        lock(Duration.ofSeconds(seconds));
+                    }
+                    break;
+                case "release":
+                    release();
+                    break;
+                case "?":
+                    System.out.println("Lock is acquired: " + isAcquired());
+                    break;
+                default:
+                    System.out.println("Unknown command: " + command);
+            }
+        }
+
+        scanner.close();
+    }
+
+}
+

coordination/recipes/src/main/java/tech/ydb/coordination/recipes/example/Main.java

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+package tech.ydb.coordination.recipes.example;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import tech.ydb.auth.iam.CloudAuthHelper;
+import tech.ydb.coordination.CoordinationClient;
+import tech.ydb.core.grpc.GrpcTransport;
+
+public class Main {
+    private final static Logger logger = LoggerFactory.getLogger(Main.class);
+
+    public static void main(String[] args) {
+        if (args.length != 1) {
+            System.err.println("Usage: java -jar jdbc-coordination-api-example.jar <connection_url>");
+            return;
+        }
+
+        try (GrpcTransport transport = GrpcTransport.forConnectionString(args[0])
+                .withAuthProvider(CloudAuthHelper.getAuthProviderFromEnviron())
+                .build()) {
+
+            logger.info("run lock app example");
+            CoordinationClient client = CoordinationClient.newClient(transport);
+            LockApp lockApp = new LockApp(client);
+            lockApp.run();
+            logger.info("lock app example finished");
+        }
+    }
+}

coordination/recipes/src/main/java/tech/ydb/coordination/recipes/example/lib/election/LeaderElectionListener.java

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+package tech.ydb.coordination.recipes.example.lib.election;
+
+public interface LeaderElectionListener {
+    void takeLeadership() throws Exception;
+}