在 Eclipse 中为 2.4.1 hadoop 映射 Reduce 客户端 jar

As per the screenshot, you are manually adding all the dependent jars to the classpath. It's highly recommended to use maven for this, which will automate the process of adding dependent jars to the classpath. We just need to add main dependent jars.
I used the following dependencies in pom.xml which helped me to run without any issues..

<properties>
    <hadoop.version>2.5.2</hadoop.version>
</properties>

<dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-mapreduce-client-core</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-yarn-api</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-yarn-common</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-auth</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-yarn-server-nodemanager</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-yarn-server-resourcemanager</artifactId>
            <version>${hadoop.version}</version>
        </dependency>
    </dependencies>  

来解决您的问题，我检查了类路径，正好有 82 个 jar 文件可用.
像这样找到每个罐子会很乏味.
您可以添加功能明智的罐子这里.
其他解决方法是，将安装的 hadoop 目录路径中的所有 jar 文件添加为 <hadoop-installed>/share/hadoop/ 并添加所有 lib 文件夹中的所有 jar.这是你能做的最好的事情.. 或
仅添加 avro 特定 jar，因为 avro 类根据屏幕截图抛出异常. 这可以解决 avro jar 问题.但您可能会面临其他依赖问题.在使用 Hadoop V1 时，我也遇到了同样的问题.所以后来我意识到并将 Maven 与 Hadoop V2 一起使用.所以不用担心依赖 jars.
您的重点将放在 Hadoop 和业务需求上.:)
希望对你有帮助..