rabbitmq-tutorials/java/RPCClient.java
2018-08-09 14:41:18 -07:00

87 lines
2.5 KiB
Java

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
import java.util.UUID;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeoutException;
public class RPCClient {
private Connection connection;
private Channel channel;
private String requestQueueName = "rpc_queue";
public RPCClient() throws IOException, TimeoutException {
ConnectionFactory factory = new ConnectionFactory();
factory.setHost("localhost");
connection = factory.newConnection();
channel = connection.createChannel();
}
public String call(String message) throws IOException, InterruptedException {
final String corrId = UUID.randomUUID().toString();
String replyQueueName = channel.queueDeclare().getQueue();
AMQP.BasicProperties props = new AMQP.BasicProperties
.Builder()
.correlationId(corrId)
.replyTo(replyQueueName)
.build();
channel.basicPublish("", requestQueueName, props, message.getBytes("UTF-8"));
final BlockingQueue<String> response = new ArrayBlockingQueue<String>(1);
String ctag = channel.basicConsume(replyQueueName, true, new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
if (properties.getCorrelationId().equals(corrId)) {
response.offer(new String(body, "UTF-8"));
}
}
});
String result = response.take();
channel.basicCancel(ctag);
return result;
}
public void close() throws IOException {
connection.close();
}
public static void main(String[] argv) {
RPCClient fibonacciRpc = null;
String response = null;
try {
fibonacciRpc = new RPCClient();
for (int i = 0; i < 32; i++) {
String i_str = Integer.toString(i);
System.out.println(" [x] Requesting fib(" + i_str + ")");
response = fibonacciRpc.call(i_str);
System.out.println(" [.] Got '" + response + "'");
}
}
catch (IOException | TimeoutException | InterruptedException e) {
e.printStackTrace();
}
finally {
if (fibonacciRpc!= null) {
try {
fibonacciRpc.close();
}
catch (IOException _ignore) {}
}
}
}
}