如何将 Apache flink 连接到 Rabbitmq?

Question

尝试将Apache Flink连接到rabbitmq时出现错误。我用Apache Maven做了这个项目，但错误仍然存在。在这个项目中，我使用来自 MVN 干净的包进行编译，但我有一个错误.后来我从 idea 编译器使用，但我有错误。

我的代码是：

package org.apache.flink;
import org.apache.flink.api.common.serialization.SimpleStringSchema;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.connectors.rabbitmq.RMQSource;
import org.apache.flink.streaming.connectors.rabbitmq.common.RMQConnectionConfig;
class App
{
public static void main( String[] args )
{
final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.enableCheckpointing(10);
final RMQConnectionConfig connectionConfig = new RMQConnectionConfig.Builder()
.setHost("local")
.setPort(5000)
.build();
final DataStream<String> stream = env
.addSource(new RMQSource<String>(
connectionConfig,            
"queueName",                 
true,                        
new SimpleStringSchema()))   
.setParallelism(1);             
}
}

我的诗是：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.apache.flink</groupId>
<artifactId>flink-connector-rabbitmq_2.12</artifactId>
<version>1.8.1</version>
<name>flink-connector-rabbitmq_2.12</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-connector-rabbitmq_2.11</artifactId>
<version>1.8.1</version>
</dependency>

<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java_2.11</artifactId>
<version>${project.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.rabbitmq</groupId>
<artifactId>amqp-client</artifactId>
<version>5.7.3</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java_2.11</artifactId>
<version>${project.version}</version>
<scope>test</scope>
<type>test-jar</type>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-runtime_2.11</artifactId>
<version>${project.version}</version>
<type>test-jar</type>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java_2.11</artifactId>
<version>${project.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.rabbitmq</groupId>
<artifactId>amqp-client</artifactId>
<version>5.7.3</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java_2.11</artifactId>
<version>${project.version}</version>
<scope>test</scope>
<type>test-jar</type>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-runtime_2.11</artifactId>
<version>${project.version}</version>
<type>test-jar</type>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-core</artifactId>
<version>1.8.1</version>
</dependency>

</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven    defaults (may be moved to parent pom) -->
<plugins>
<!-- clean lifecycle, see https://maven.apache.org/ref/current  /maven-core/lifecycles.html#clean_Lifecycle -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- default lifecycle, jar packaging: see   https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.7.1</version>
</plugin>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>3.0.0</version>
</plugin>
</plugins>
</plugin Management>
</build>
</project>

当我运行程序时，我遇到以下错误

我的错误是：

Error: A JNI error has occurred, please check your installation and  try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache /flink/streaming/api/functions/source/SourceFunction
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at   sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at  sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException:   org.apache.flink.streaming.api.functions.source.SourceFunction
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 7 more

请帮助我

Answer 1

这里的问题是您在provided范围内有您的 Flink 依赖项，因为通常如果您在 Flink 集群上运行您的应用程序，Flink 二进制文件已经存在，因此您不需要将它们包含在您的胖罐中，因此它们在范围provided中。但是我假设您正在本地运行您的作业，因此 Flink 依赖项不可用于编译，在这种情况下，您需要更改范围，以便依赖项在编译时可用。如果您更改 Flink 依赖项的scope或将其从pom.xml中完全删除(默认范围为compile)，它应该可以正常工作。