src/test/java/org/casbin/watcher/example/RabbitMQWatcherDemo.java - casbin-jcasbin-rabbitmq-watcher - Git at Google

 // Copyright 2024 The casbin Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package org.casbin.watcher.example;

 import org.casbin.jcasbin.main.Enforcer;
 import org.casbin.watcher.RabbitMQWatcher;

 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;

 /**
  * Demo class showing how to use RabbitMQWatcher with jCasbin.
  *
  * This example demonstrates:
  * 1. Creating a RabbitMQWatcher and connecting to RabbitMQ
  * 2. Integrating the watcher with a Casbin enforcer
  * 3. Setting up automatic policy reloading when updates are received
  * 4. Broadcasting policy updates to other instances
  */
 public class RabbitMQWatcherDemo {

     /**
      * Example 1: Basic usage with default exchange
      */
     public static void basicExample() throws Exception {
         // Create model and policy files
         File modelFile = createModelFile();
         File policyFile = createPolicyFile();

         // Initialize the enforcer
         Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

         // Create watcher with RabbitMQ connection
         // Replace with your RabbitMQ server details
         RabbitMQWatcher watcher = new RabbitMQWatcher("amqp://localhost:5672");

         // Set the watcher on the enforcer
         enforcer.setWatcher(watcher);

         // Set up callback to reload policy when updates are received from other instances
         watcher.setUpdateCallback(() -> {
             System.out.println("Policy update received, reloading...");
             enforcer.loadPolicy();
         });

         // Make a policy change
         enforcer.addPolicy("alice", "data1", "read");
         enforcer.savePolicy();

         // Notify other instances about the policy update
         watcher.update();
         System.out.println("Policy update broadcasted to other instances");

         // Test the policy
         boolean allowed = enforcer.enforce("alice", "data1", "read");
         System.out.println("Alice can read data1: " + allowed);

         // Clean up
         watcher.close();
         modelFile.delete();
         policyFile.delete();
     }

     /**
      * Example 2: Using host and port instead of URI
      */
     public static void hostPortExample() throws Exception {
         File modelFile = createModelFile();
         File policyFile = createPolicyFile();

         Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

         // Connect using host and port
         RabbitMQWatcher watcher = new RabbitMQWatcher("localhost", 5672);

         enforcer.setWatcher(watcher);
         watcher.setUpdateCallback(() -> {
             enforcer.loadPolicy();
         });

         // Use the enforcer...
         enforcer.addPolicy("bob", "data2", "write");
         enforcer.savePolicy();
         watcher.update();

         // Clean up
         watcher.close();
         modelFile.delete();
         policyFile.delete();
     }

     /**
      * Example 3: Using custom exchange name
      */
     public static void customExchangeExample() throws Exception {
         File modelFile = createModelFile();
         File policyFile = createPolicyFile();

         Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

         // Use custom exchange name for isolation
         String customExchange = "my_app_casbin_updates";
         RabbitMQWatcher watcher = new RabbitMQWatcher("amqp://localhost:5672", customExchange);

         enforcer.setWatcher(watcher);
         watcher.setUpdateCallback(() -> {
             enforcer.loadPolicy();
         });

         // Use the enforcer...
         enforcer.addPolicy("carol", "data3", "delete");
         enforcer.savePolicy();
         watcher.update();

         // Clean up
         watcher.close();
         modelFile.delete();
         policyFile.delete();
     }

     /**
      * Example 4: Multi-instance scenario
      * This demonstrates how two separate instances can sync policies
      */
     public static void multiInstanceExample() throws Exception {
         File modelFile = createModelFile();
         File policyFile = createPolicyFile();

         // Instance 1
         Enforcer enforcer1 = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());
         RabbitMQWatcher watcher1 = new RabbitMQWatcher("amqp://localhost:5672");
         enforcer1.setWatcher(watcher1);
         watcher1.setUpdateCallback(() -> {
             System.out.println("Instance 1: Reloading policy...");
             enforcer1.loadPolicy();
         });

         // Instance 2 (simulating a different service/server)
         Enforcer enforcer2 = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());
         RabbitMQWatcher watcher2 = new RabbitMQWatcher("amqp://localhost:5672");
         enforcer2.setWatcher(watcher2);
         watcher2.setUpdateCallback(() -> {
             System.out.println("Instance 2: Reloading policy...");
             enforcer2.loadPolicy();
         });

         // Wait a bit for consumers to start
         Thread.sleep(500);

         System.out.println("Initial state - Instance 1 can alice read data1: "
             + enforcer1.enforce("alice", "data1", "read"));
         System.out.println("Initial state - Instance 2 can alice read data1: "
             + enforcer2.enforce("alice", "data1", "read"));

         // Update policy in instance 1
         System.out.println("\nAdding policy in Instance 1...");
         enforcer1.addPolicy("alice", "data1", "read");
         enforcer1.savePolicy();
         watcher1.update();  // This broadcasts to instance 2

         // Wait for instance 2 to receive the update
         Thread.sleep(1000);

         System.out.println("\nAfter update - Instance 1 can alice read data1: "
             + enforcer1.enforce("alice", "data1", "read"));
         System.out.println("After update - Instance 2 can alice read data1: "
             + enforcer2.enforce("alice", "data1", "read"));

         // Clean up
         watcher1.close();
         watcher2.close();
         modelFile.delete();
         policyFile.delete();
     }

     /**
      * Creates a temporary model file for the examples
      */
     private static File createModelFile() throws IOException {
         File modelFile = File.createTempFile("rbac_model", ".conf");
         try (FileWriter writer = new FileWriter(modelFile)) {
             writer.write("[request_definition]\n");
             writer.write("r = sub, obj, act\n\n");
             writer.write("[policy_definition]\n");
             writer.write("p = sub, obj, act\n\n");
             writer.write("[role_definition]\n");
             writer.write("g = _, _\n\n");
             writer.write("[policy_effect]\n");
             writer.write("e = some(where (p.eft == allow))\n\n");
             writer.write("[matchers]\n");
             writer.write("m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act\n");
         }
         return modelFile;
     }

     /**
      * Creates a temporary policy file for the examples
      */
     private static File createPolicyFile() throws IOException {
         File policyFile = File.createTempFile("rbac_policy", ".csv");
         try (FileWriter writer = new FileWriter(policyFile)) {
             writer.write("p, admin, data, read\n");
             writer.write("p, admin, data, write\n");
         }
         return policyFile;
     }

     /**
      * Main method to run the examples
      * Note: Requires a running RabbitMQ instance on localhost:5672
      */
     public static void main(String[] args) {
         try {
             System.out.println("=== RabbitMQ Watcher Demo ===\n");

             System.out.println("Running Example 1: Basic Usage");
             basicExample();

             System.out.println("\n\nRunning Example 2: Host and Port");
             hostPortExample();

             System.out.println("\n\nRunning Example 3: Custom Exchange");
             customExchangeExample();

             System.out.println("\n\nRunning Example 4: Multi-Instance Sync");
             multiInstanceExample();

             System.out.println("\n=== All examples completed ===");
         } catch (Exception e) {
             System.err.println("Error running examples: " + e.getMessage());
             e.printStackTrace();
         }
     }
 }
	// Copyright 2024 The casbin Authors. All Rights Reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package org.casbin.watcher.example;

	import org.casbin.jcasbin.main.Enforcer;
	import org.casbin.watcher.RabbitMQWatcher;

	import java.io.File;
	import java.io.FileWriter;
	import java.io.IOException;

	/**
	* Demo class showing how to use RabbitMQWatcher with jCasbin.
	*
	* This example demonstrates:
	* 1. Creating a RabbitMQWatcher and connecting to RabbitMQ
	* 2. Integrating the watcher with a Casbin enforcer
	* 3. Setting up automatic policy reloading when updates are received
	* 4. Broadcasting policy updates to other instances
	*/
	public class RabbitMQWatcherDemo {

	/**
	* Example 1: Basic usage with default exchange
	*/
	public static void basicExample() throws Exception {
	// Create model and policy files
	File modelFile = createModelFile();
	File policyFile = createPolicyFile();

	// Initialize the enforcer
	Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

	// Create watcher with RabbitMQ connection
	// Replace with your RabbitMQ server details
	RabbitMQWatcher watcher = new RabbitMQWatcher("amqp://localhost:5672");

	// Set the watcher on the enforcer
	enforcer.setWatcher(watcher);

	// Set up callback to reload policy when updates are received from other instances
	watcher.setUpdateCallback(() -> {
	System.out.println("Policy update received, reloading...");
	enforcer.loadPolicy();
	});

	// Make a policy change
	enforcer.addPolicy("alice", "data1", "read");
	enforcer.savePolicy();

	// Notify other instances about the policy update
	watcher.update();
	System.out.println("Policy update broadcasted to other instances");

	// Test the policy
	boolean allowed = enforcer.enforce("alice", "data1", "read");
	System.out.println("Alice can read data1: " + allowed);

	// Clean up
	watcher.close();
	modelFile.delete();
	policyFile.delete();
	}

	/**
	* Example 2: Using host and port instead of URI
	*/
	public static void hostPortExample() throws Exception {
	File modelFile = createModelFile();
	File policyFile = createPolicyFile();

	Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

	// Connect using host and port
	RabbitMQWatcher watcher = new RabbitMQWatcher("localhost", 5672);

	enforcer.setWatcher(watcher);
	watcher.setUpdateCallback(() -> {
	enforcer.loadPolicy();
	});

	// Use the enforcer...
	enforcer.addPolicy("bob", "data2", "write");
	enforcer.savePolicy();
	watcher.update();

	// Clean up
	watcher.close();
	modelFile.delete();
	policyFile.delete();
	}

	/**
	* Example 3: Using custom exchange name
	*/
	public static void customExchangeExample() throws Exception {
	File modelFile = createModelFile();
	File policyFile = createPolicyFile();

	Enforcer enforcer = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());

	// Use custom exchange name for isolation
	String customExchange = "my_app_casbin_updates";
	RabbitMQWatcher watcher = new RabbitMQWatcher("amqp://localhost:5672", customExchange);

	enforcer.setWatcher(watcher);
	watcher.setUpdateCallback(() -> {
	enforcer.loadPolicy();
	});

	// Use the enforcer...
	enforcer.addPolicy("carol", "data3", "delete");
	enforcer.savePolicy();
	watcher.update();

	// Clean up
	watcher.close();
	modelFile.delete();
	policyFile.delete();
	}

	/**
	* Example 4: Multi-instance scenario
	* This demonstrates how two separate instances can sync policies
	*/
	public static void multiInstanceExample() throws Exception {
	File modelFile = createModelFile();
	File policyFile = createPolicyFile();

	// Instance 1
	Enforcer enforcer1 = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());
	RabbitMQWatcher watcher1 = new RabbitMQWatcher("amqp://localhost:5672");
	enforcer1.setWatcher(watcher1);
	watcher1.setUpdateCallback(() -> {
	System.out.println("Instance 1: Reloading policy...");
	enforcer1.loadPolicy();
	});

	// Instance 2 (simulating a different service/server)
	Enforcer enforcer2 = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());
	RabbitMQWatcher watcher2 = new RabbitMQWatcher("amqp://localhost:5672");
	enforcer2.setWatcher(watcher2);
	watcher2.setUpdateCallback(() -> {
	System.out.println("Instance 2: Reloading policy...");
	enforcer2.loadPolicy();
	});

	// Wait a bit for consumers to start
	Thread.sleep(500);

	System.out.println("Initial state - Instance 1 can alice read data1: "
	+ enforcer1.enforce("alice", "data1", "read"));
	System.out.println("Initial state - Instance 2 can alice read data1: "
	+ enforcer2.enforce("alice", "data1", "read"));

	// Update policy in instance 1
	System.out.println("\nAdding policy in Instance 1...");
	enforcer1.addPolicy("alice", "data1", "read");
	enforcer1.savePolicy();
	watcher1.update(); // This broadcasts to instance 2

	// Wait for instance 2 to receive the update
	Thread.sleep(1000);

	System.out.println("\nAfter update - Instance 1 can alice read data1: "
	+ enforcer1.enforce("alice", "data1", "read"));
	System.out.println("After update - Instance 2 can alice read data1: "
	+ enforcer2.enforce("alice", "data1", "read"));

	// Clean up
	watcher1.close();
	watcher2.close();
	modelFile.delete();
	policyFile.delete();
	}

	/**
	* Creates a temporary model file for the examples
	*/
	private static File createModelFile() throws IOException {
	File modelFile = File.createTempFile("rbac_model", ".conf");
	try (FileWriter writer = new FileWriter(modelFile)) {
	writer.write("[request_definition]\n");
	writer.write("r = sub, obj, act\n\n");
	writer.write("[policy_definition]\n");
	writer.write("p = sub, obj, act\n\n");
	writer.write("[role_definition]\n");
	writer.write("g = _, _\n\n");
	writer.write("[policy_effect]\n");
	writer.write("e = some(where (p.eft == allow))\n\n");
	writer.write("[matchers]\n");
	writer.write("m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act\n");
	}
	return modelFile;
	}

	/**
	* Creates a temporary policy file for the examples
	*/
	private static File createPolicyFile() throws IOException {
	File policyFile = File.createTempFile("rbac_policy", ".csv");
	try (FileWriter writer = new FileWriter(policyFile)) {
	writer.write("p, admin, data, read\n");
	writer.write("p, admin, data, write\n");
	}
	return policyFile;
	}

	/**
	* Main method to run the examples
	* Note: Requires a running RabbitMQ instance on localhost:5672
	*/
	public static void main(String[] args) {
	try {
	System.out.println("=== RabbitMQ Watcher Demo ===\n");

	System.out.println("Running Example 1: Basic Usage");
	basicExample();

	System.out.println("\n\nRunning Example 2: Host and Port");
	hostPortExample();

	System.out.println("\n\nRunning Example 3: Custom Exchange");
	customExchangeExample();

	System.out.println("\n\nRunning Example 4: Multi-Instance Sync");
	multiInstanceExample();

	System.out.println("\n=== All examples completed ===");
	} catch (Exception e) {
	System.err.println("Error running examples: " + e.getMessage());
	e.printStackTrace();
	}
	}
	}