noclassdeffounderror

uemypmqf  于 2021-06-04  发布在  Kafka
关注(0)|答案(2)|浏览(527)

我有以下代码:

public KafkaReader(KafkaConsumer<Long, byte[]> consumer, String topic) {
    this.consumer = consumer;
    this.topicPartition = new TopicPartition(topic, ((consumer.partitionsFor(topic).get(0)).partition()));
    consumer.assign(Collections.singleton(topicPartition));
}

但在执行consumer.partitionsfor(topic)时,出现以下错误:

java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/JsonNode

at org.apache.kafka.common.requests.MetadataRequest$Builder.<clinit>(MetadataRequest.java:36)
at org.apache.kafka.clients.consumer.KafkaConsumer.partitionsFor(KafkaConsumer.java:1962)
at org.apache.kafka.clients.consumer.KafkaConsumer.partitionsFor(KafkaConsumer.java:1930)
at data.KafkaReader.<init>(KafkaReader.java:20)
at data.KafkaReaderTest.playground(KafkaReaderTest.java:12)

... 原因:java.lang.classnotfoundexception:com.fasterxml.jackson.databind.jsonnode位于java.base/jdk.internal.loader.builtinclassloader.loadclass(builtinclassloader)。java:581)在java.base/jdk.internal.loader.classloaders$appclassloader.loadclass(classloaders。java:178)在java.base/java.lang.classloader.loadclass(classloader。java:522) ... 68个以上
在pom.xml中,我定义了以下依赖项:

<dependencies>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>${junit.jupiter.version}</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.hamcrest</groupId>
        <artifactId>hamcrest-all</artifactId>
        <version>1.3</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>commons-cli</groupId>
        <artifactId>commons-cli</artifactId>
        <version>1.4</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.12</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-clients</artifactId>
        <version>2.6.0</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.25</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.8.10</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.8.10</version>
    </dependency>
</dependencies>

我所能找到的建议就是将jackson注解和-core添加到maven依赖项中,但没有任何帮助。

smdnsysy

smdnsysy1#

classnotfoundexception:com.fasterxml.jackson.databind.jsonnode
所以你需要

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.10</version>
</dependency>

但是,您应该真正使用 jackson-bom 一致地导入所有相关的依赖项版本

vnjpjtjt

vnjpjtjt2#

这是2.6版客户端中的一个错误:https://issues.apache.org/jira/browse/kafka-10378
我建议在2.6.1或2.7发布之前,坚持使用2.5客户端。除非有一个关键的2.6特性是你所不能缺少的,那么包含你自己的依赖性的建议是合理的。

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