如何通过 Maven 在 Intellij 中导入 hadoop.hbase.mapreduce？

Question

我打算在 IntelliJ 中使用 Hadoop 的伪分布式模式。目前，我可以在笔记本电脑上成功运行 WordCount 示例代码。然后，我尝试编写另一个代码，其中包含 hbase 的使用。但是，我无法在我的代码中导入 import org.apache.hadoop.hbase.mapreduce.TableReducer;。我尝试添加不同的 Maven 依赖项，但它不起作用。

这里是hadoop代码：

package topten;

import java.io.*;
import java.util.Map;
import java.util.TreeMap;
import java.util.HashMap;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;

public class TopTen {

    public static class TopTenMapper extends Mapper<Object, Text, NullWritable, Text> {
        // Stores a map of user reputation to the record
        TreeMap<Integer, Text> repToRecordMap = new TreeMap<Integer, Text>();

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
        //<FILL IN>
        }

        protected void cleanup(Context context) throws IOException, InterruptedException {
            // Output our ten records to the reducers with a null key
        //<FILL IN>
        }
    }

    public static class TopTenReducer extends TableReducer<NullWritable, Text, NullWritable> {
        // Stores a map of user reputation to the record
        private TreeMap<Integer, Text> repToRecordMap = new TreeMap<Integer, Text>();

        public void reduce(NullWritable key, Iterable<Text> values, Context context) throws IOException, InterruptedException {
        //<FILL IN>
        }
    }

    public static void main(String[] args) throws Exception {
    }
}

这是我的 Maven 配置文件：

<?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>com.dataintensivecomputing</groupId>
    <artifactId>hadoop</artifactId>
    <version>1.0-SNAPSHOT</version>

    <repositories>
        <repository>
            <id>apache</id>
            <url>http://maven.apache.org</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
            <version>1.2.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>2.7.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-hdfs</artifactId>
            <version>2.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase</artifactId>
            <version>2.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-server</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-client</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-common</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-mapreduce</artifactId>
            <version>2.1.0</version>
        </dependency>
    </dependencies>
</project>

谁能告诉我应该将哪些 Maven 依赖项添加到 pom.xml 文件中？

Answer 1

根据 Github 源代码，这对于 HBase 的多个版本都是正确的

    <dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-mapreduce</artifactId>
        <version>${hbase.version}</version>
    </dependency>

目前尚不清楚您正在运行的 Hbase + Hadoop 的实际版本，但您确实应该让它们在您的 POM 中保持一致

<properties>
  <hadoop.version>2.7.2</hadoop.version>
  <hbase.version>2.1.0</hbase.version>
<properties>

现在，将这些属性用于每个依赖项的相同 group.id，并运行 mvn clean compile，如果这些类确实存在，则不应该有任何导入问题。

您还可以为 IntelliJ 启用自动导入