Apache Flink: java.lang.NoClassDefFoundError

问题

I'm trying to follow this example but when I try to compile it, I have this error:

Error: Unable to initialize main class com.amazonaws.services.kinesisanalytics.aws
Caused by: java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/functions/source/SourceFunction

The error is due this code:

    private static DataStream<String> createSourceFromStaticConfig(StreamExecutionEnvironment env) {
        Properties inputProperties = new Properties();
        inputProperties.setProperty(ConsumerConfigConstants.AWS_REGION, region);
        inputProperties.setProperty(ConsumerConfigConstants.STREAM_INITIAL_POSITION, "LATEST");

        return env.addSource(new FlinkKinesisConsumer<>(inputStreamName, new SimpleStringSchema(), inputProperties));
    }

And I suppose this is the problematic line:

  return env.addSource(new FlinkKinesisConsumer<>(inputStreamName, new SimpleStringSchema(), inputProperties));

This are my maven dependencies:

What could be wrong? any dependencies, version?

Note: If I comment the problematic line, the program run without problem.

POM file

<?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>as</groupId>
    <artifactId>a</artifactId>
    <version>1</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <geotools.version>21-SNAPSHOT</geotools.version>
        <java.version>1.8</java.version>
        <scala.binary.version>2.11</scala.binary.version>
        <flink.version>1.6.2</flink.version>
        <kda.version>1.0.1</kda.version>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.0.0</version>
                <executions>
                    <!-- Run shade goal on package phase -->
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <artifactSet>
                                <excludes>
                                    <exclude>org.apache.flink:force-shading</exclude>
                                    <exclude>com.google.code.findbugs:jsr305</exclude>
                                    <exclude>org.slf4j:*</exclude>
                                    <exclude>log4j:*</exclude>
                                </excludes>
                            </artifactSet>
                            <filters>
                                <filter>
                                    <!-- Do not copy the signatures in the META-INF folder.
                                    Otherwise, this might cause SecurityExceptions when using the JAR. -->
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>com.amazonaws.services.kinesisanalytics.aws</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>

    </build>
    <dependencies>
        <dependency>
            <groupId>org.locationtech.jts</groupId>
            <artifactId>jts-core</artifactId>
            <version>1.16.0</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-geojson</artifactId>
            <version>${geotools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-geojsondatastore</artifactId>
            <version>${geotools.version}</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-main</artifactId>
            <version>${geotools.version}</version>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-kinesisanalytics-runtime</artifactId>
            <version>${kda.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-kinesis_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-java_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-kinesisanalytics-flink</artifactId>
            <version>${kda.version}</version>
        </dependency>
    </dependencies>
</project>

回答1:

Your error is here:

<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-streaming-java_${scala.binary.version}</artifactId>
    <version>${flink.version}</version>
    <scope>provided</scope>
</dependency>

The scope is provided. This means, that your program expects that library to be accessible during runtime, but it can't find it nowhere.

NoClassDefFound means it was accessible for compile time, but not during the execution.

Change the scope to compile in order to resolve this issue. Also, you can take a look here for more technical info.

来源：https://stackoverflow.com/questions/54106187/apache-flink-java-lang-noclassdeffounderror