Flink：将Redis中的数据作为Flink的数据源

快来打我* 2024-03-23 13:00 49阅读 0赞

### 依赖 ###

<dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-java</artifactId>
        <version>1.7.2</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-streaming-java_2.12</artifactId>
        <version>1.7.2</version>
        
    </dependency>
    
    <dependency>
        <groupId>org.apache.flink</groupId>
        <artifactId>flink-connector-redis_2.11</artifactId>
        <version>1.1.5</version>
    </dependency>

### 代码 ###

import org.apache.flink.streaming.api.functions.source.SourceFunction;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import redis.clients.jedis.Jedis;
    import redis.clients.jedis.exceptions.JedisConnectionException;
    
    /**
     * redis中进行数据初始化
     * 
     * hset user1 id 1
     * hset user1 name jack
     * hset user1 age 24
     * hset user1 address SH
     * 
     * 需要把属性名和属性值的对应关系组装成java的hashmap
     *
     *  SourceFunction中泛型为HashMap<String, String>数据类型即为从redis处理后给flink的数据类型
     */
    public class MyRedisSource implements SourceFunction<HashMap<String, String>> {
        private Logger logger = LoggerFactory.getLogger(MyRedisSource.class);
    
        private final long SLEEP_MILLION = 60000;
    
        private boolean isRunning = true;
        private Jedis jedis = null;
    
        // SourceContext中泛型为HashMap<String, String>数据类型即为从redis处理后给flink的数据类型
        public void run(SourceContext<HashMap<String, String>> ctx) throws Exception {
    
            this.jedis = new Jedis("192.168.25.129", 6379);
            //存储所有国家和大区的对应关系
            HashMap<String, String> keyValueMap = new HashMap<String, String>();
            while (isRunning) {
                try {
                    keyValueMap.clear();
                    for (int i = 1; i <= 100; i++) {
                        String key1 = "user" + i;
                        Map<String, String> map = jedis.hgetAll(key1);
                        for (Map.Entry<String, String> entry : map.entrySet()) {
                            String key2 = entry.getKey();
                            String value = entry.getValue();
                            keyValueMap.put(key1 + "." + key2, value);
                        }
                    }
                    if (keyValueMap.size() > 0) {
                        ctx.collect(keyValueMap);
                    } else {
                        logger.warn("从redis中获取的数据为空！！！");
                    }
                    Thread.sleep(SLEEP_MILLION);
                } catch (JedisConnectionException e) {
                    logger.error("redis链接异常，重新获取链接", e.getCause());
                    jedis = new Jedis("192.168.25.129", 6379);
                } catch (Exception e) {
                    logger.error("source 数据源异常", e.getCause());
                }
            }
        }
    
        public void cancel() {
            isRunning = false;
            if (jedis != null) {
                jedis.close();
            }
        }
    }

import org.apache.flink.streaming.api.datastream.DataStream;
    import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    
    public class FlinkSourceFromRedis {
    
        public static void main(String[] args) throws Exception {
    
            StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
            DataStream<HashMap<String, String>> data = env.addSource(new MyRedisSource());
    
            data.print();
            env.execute();
        }
    }