PipeTransExample.java

// EXAMPLE: pipe_trans_tutorial
// REMOVE_START
package io.redis.examples;

import org.junit.jupiter.api.Test;
// REMOVE_END
import java.util.List;

import redis.clients.jedis.UnifiedJedis;
import redis.clients.jedis.AbstractPipeline;
import redis.clients.jedis.AbstractTransaction;
import redis.clients.jedis.Response;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class PipeTransExample {

    @Test
    public void run() {
        UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379");

        // REMOVE_START
        for (int i = 0; i < 5; i++) {
            jedis.del(String.format("seat:%d", i));
        }

        jedis.del("counter:1", "counter:2", "counter:3", "shellpath");
        // REMOVE_END

        // STEP_START basic_pipe
        // Make sure you close the pipeline after use to release resources
        // and return the connection to the pool.
        try (AbstractPipeline pipe = jedis.pipelined()) {

            for (int i = 0; i < 5; i++) {
                pipe.set(String.format("seat:%d", i), String.format("#%d", i));
            }

            pipe.sync();
        }

        try (AbstractPipeline pipe = jedis.pipelined()) {

            Response<String> resp0 = pipe.get("seat:0");
            Response<String> resp3 = pipe.get("seat:3");
            Response<String> resp4 = pipe.get("seat:4");

            pipe.sync();

            // Responses are available after the pipeline has executed.
            System.out.println(resp0.get()); // >>> #0
            System.out.println(resp3.get()); // >>> #3
            System.out.println(resp4.get()); // >>> #4


            // REMOVE_START
            assertEquals("#0", resp0.get());
            assertEquals("#3", resp3.get());
            assertEquals("#4", resp4.get());
            // REMOVE_END
        }
        // STEP_END

        // STEP_START basic_trans
        try ( AbstractTransaction trans = jedis.multi()) {

           trans.incrBy("counter:1", 1);
           trans.incrBy("counter:2", 2);
           trans.incrBy("counter:3", 3);

           trans.exec();
        }
        System.out.println(jedis.get("counter:1")); // >>> 1
        System.out.println(jedis.get("counter:2")); // >>> 2
        System.out.println(jedis.get("counter:3")); // >>> 3
        // STEP_END
        // REMOVE_START
        assertEquals("1", jedis.get("counter:1"));
        assertEquals("2", jedis.get("counter:2"));
        assertEquals("3", jedis.get("counter:3"));
        // REMOVE_END

        // STEP_START trans_watch
        // Set initial value of `shellpath`.
        jedis.set("shellpath", "/usr/syscmds/");

        // Start the transaction and watch the key we are about to update.
        try (AbstractTransaction trans = jedis.transaction(false)) { // create a Transaction object without sending MULTI command
            trans.watch("shellpath"); // send WATCH command(s)
            trans.multi(); // send MULTI command

            String currentPath = jedis.get("shellpath");
            String newPath = currentPath + ":/usr/mycmds/";

            // Commands added to the `trans` object
            // will be buffered until `trans.exec()` is called.
            Response<String> setResult = trans.set("shellpath", newPath);
            List<Object> transResults = trans.exec();

            // The `exec()` call returns null if the transaction failed.
            if (transResults != null) {
                // Responses are available if the transaction succeeded.
                System.out.println(setResult.get()); // >>> OK

                // You can also get the results from the list returned by
                // `trans.exec()`.
                for (Object item: transResults) {
                    System.out.println(item);
                }
                // >>> OK

                System.out.println(jedis.get("shellpath"));
                // >>> /usr/syscmds/:/usr/mycmds/
            }
            // REMOVE_START
            assertEquals("/usr/syscmds/:/usr/mycmds/", jedis.get("shellpath"));
            assertEquals("OK", setResult.get());
            assertEquals(1, transResults.size());
            assertEquals("OK", transResults.get(0).toString());
            // REMOVE_END
        }
        // STEP_END

// HIDE_START
        jedis.close();
    }   
}
// HIDE_END