Question

我正在运行Hadoop 2.8.1和Hive 2.3.0 我想从Hive中创建的表中读取值目前的例外是

java.lang.ClassNotFoundException: org.apache.hadoop.tracing.SpanReceiverHost
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

以下是我用来阅读表格的代码

 public static final String HIVEURL = "jdbc:hive2://localhost:10000";
    public static final String DB_NAME = "default";
    public static final String TABLE_NAME = "order_line";

    public static void main(String[] args) throws Exception {
        HiveConf hiveConf = new HiveConf();
        //hiveConf.setVar(HiveConf.ConfVars.METASTOREURIS, HIVEURL);
        HiveMetaStoreClient hiveClient = new HiveMetaStoreClient(hiveConf);

        Job job =Job.getInstance();
        TaskAttemptContext ctx = new TaskAttemptContextImpl(job.getConfiguration(), new TaskAttemptID());
        HCatInputFormat hcif = HCatInputFormat.setInput(job, DB_NAME, TABLE_NAME);


        HCatSchema allCols = hcif.getTableSchema(job.getConfiguration());
        List<HCatFieldSchema> usedList = new ArrayList<>();
        usedList.add(allCols.get(2)); // por ex...
        HCatSchema someCols = new HCatSchema(usedList);
        hcif.setOutputSchema(job, someCols);

        for(InputSplit split: hcif.getSplits(job)) {
            RecordReader<WritableComparable, HCatRecord> rr = hcif.createRecordReader(split,ctx);
            rr.initialize(split, ctx);

            while(rr.nextKeyValue()) {
                HCatRecord record = rr.getCurrentValue();
                // usar record.get(...) para obter a coluna...
                //Object o = record.get(1);
                //System.out.println(o.toString());

            }

            rr.close();
        }

        hiveClient.close();
    }

这是我用过的Pom文件

org.apache.hive.hcatalog 蜂房hcatalog核心 2.3.0 org.apache.hive.hcatalog 蜂房hcatalog 0.13.1-cdh5.3.5 org.apache.hive 蜂房常见 2.3.0

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive</artifactId>
        <version>0.13.1-cdh5.3.5</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hive</groupId>
        <artifactId>hive-metastore</artifactId>
        <version>2.3.0</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-common -->
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.8.1</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-core -->
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>2.6.0-mr1-cdh5.12.1</version>
        <type>pom</type>
    </dependency>

    <dependency>
        <groupId>org.apache.thrift</groupId>
        <artifactId>libthrift</artifactId>
        <version>0.9.3</version>
    </dependency>
</dependencies>

Answer 1

我无法从堆栈跟踪片段中看到实际导致loadClass的原因，但看起来该类实际上并不存在于hadoop-common你的版本2.8.1中重新使用。它似乎在2.7.2

之后消失了

它或同名的东西在hbase source

中

你有没有混合版本的版本？

Answer 2

<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-common -->
<!-- org/apache/hadoop/tracing/SpanReceiverHost The Last version is hadoop-common 2.7.7-->
<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-common</artifactId>
    <version>2.7.7</version>
</dependency>

线程“main”中的异常java.lang.NoClassDefFoundError：org / apache / hadoop / tracing / SpanReceiverHost

2 个答案: