导入 org.apache 无法解析

Question

有很多与之相关的问题，但我找不到任何有用的解决方案。

无法为以下提到的行解析导入 org.apache。

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;

我正在关注这个[教程] 。 除了这个我都准备好了，请帮忙。 提前致谢。

Answer 1

首先为eclipse安装maven。 然后更改文件 pom，将库添加到 pom 文件。

这是我的 pom 文件，希望对您有所帮助：

<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</groupId>
<artifactId>pigexample</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>pigexample</name>
<url>http://maven.apache.org</url>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<repositories>
    <repository>
        <id>java.net</id>
        <url>http://download.java.net/maven/2/</url>
    </repository>
    <repository>
        <id>cloudera-releases</id>
        <url>https://repository.cloudera.com/artifactory/cloudera-repos</url>
        <releases>
            <enabled>true</enabled>
        </releases>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.0.0-cdh4.1.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-hdfs</artifactId>
        <version>2.0.0-cdh4.1.2</version>
    </dependency>

    <dependency>
        <groupId>org.apache.pig</groupId>
        <artifactId>pig</artifactId>
        <version>0.10.0-cdh4.1.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.3.2</version>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>com.biglabs.ssm</groupId>
        <artifactId>ssm-recommendation-data</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.4</version>
            <executions>
                <execution>
                    <id>generateSingle</id>
                    <phase>package</phase>
                    <goals>
                        <goal>single</goal>
                    </goals>
                    <configuration>
                        <finalName>${project.artifactId}-${project.version}-full</finalName>
                        <descriptorRefs>
                            We call the predefined descriptor 'jar-with-dependencies'
                            <descriptorRef>jar-with-dependencies </descriptorRef>
                        </descriptorRefs>
                        <appendAssemblyId>false</appendAssemblyId>
                        <archive>
                            <manifest>
                            </manifest>
                        </archive>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>