example.springdata.redis.commands.KeyOperationsTests.java Source code

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Here is the source code for example.springdata.redis.commands.KeyOperationsTests.java

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/*
 * Copyright 2014-2016 the original author or authors.
 *
 * 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 example.springdata.redis.commands;

import example.springdata.redis.test.util.RequiresRedisServer;

import java.util.Iterator;
import java.util.Set;
import java.util.UUID;

import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.Cursor;
import org.springframework.data.redis.core.ScanOptions;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * Show usage of operations on redis keys using low level API provided by {@link RedisConnection}.
 * 
 * @author Christoph Strobl
 */
@RunWith(SpringRunner.class)
@SpringBootApplication
public class KeyOperationsTests {

    // we only want to run this tests when redis is up an running
    public static @ClassRule RequiresRedisServer requiresServer = RequiresRedisServer.onLocalhost();

    private static final String PREFIX = KeyOperationsTests.class.getSimpleName();
    private static final String KEY_PATTERN = PREFIX + "*";

    @Autowired
    RedisConnectionFactory connectionFactory;

    private RedisConnection connection;
    private RedisSerializer<String> serializer = new StringRedisSerializer();

    @Before
    public void setUp() {
        this.connection = connectionFactory.getConnection();
    }

    /**
     * Uses {@code KEYS} command for loading all matching keys. <br />
     * Note that {@code KEYS} is a blocking command that potentially might affect other operations execution time. <br />
     * All keys will be loaded within <strong>one single</strong> operation.
     */
    @Test
    public void iterateOverKeysMatchingPrefixUsingKeysCommand() {

        generateRandomKeys(1000);

        Set<byte[]> keys = this.connection.keys(serializer.serialize(KEY_PATTERN));
        printKeys(keys.iterator());
    }

    /**
     * Uses {@code SCAN} command for loading all matching keys. <br />
     * {@code SCAN} uses a cursor on server side returning only a subset of the available data with the possibility to
     * ripple load further elements using the cursors position. <br />
     * All keys will be loaded using <strong>multiple</strong> operations.
     */
    @Test
    public void iterateOverKeysMatchingPrefixUsingScanCommand() {

        generateRandomKeys(1000);

        Cursor<byte[]> cursor = this.connection.scan(ScanOptions.scanOptions().match(KEY_PATTERN).build());
        printKeys(cursor);
    }

    private void printKeys(Iterator<byte[]> keys) {

        int i = 0;
        while (keys.hasNext()) {
            System.out.println(new String(keys.next()));
            i++;
        }
        System.out.println(String.format("Total No. found: %s", i));
    }

    private void generateRandomKeys(int nrKeys) {

        for (int i = 0; i < nrKeys; i++) {
            this.connection.set((PREFIX + "-" + i).getBytes(), UUID.randomUUID().toString().getBytes());
        }
    }
}