mrunit的问题

最新推荐文章于 2019-02-26 17:43:12 发布

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最新推荐文章于 2019-02-26 17:43:12 发布

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3. MRUnit 单元测试

3.1 MRUnit jar下载

搜索下载时注意，一定要下载hadoop2.x版本的，不然会报兼容错误。

报错信息：

java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskInputOutputContext, but class was expected
	at org.apache.hadoop.mrunit.internal.mapreduce.AbstractMockContextWrapper.createCommon(AbstractMockContextWrapper.java:59)
	at org.apache.hadoop.mrunit.internal.mapreduce.MockMapContextWrapper.create(MockMapContextWrapper.java:77)
	at org.apache.hadoop.mrunit.internal.mapreduce.MockMapContextWrapper.<init>(MockMapContextWrapper.java:68)
	at org.apache.hadoop.mrunit.mapreduce.MapDriver.getContextWrapper(MapDriver.java:167)
	at org.apache.hadoop.mrunit.mapreduce.MapDriver.run(MapDriver.java:144)
	at org.apache.hadoop.mrunit.TestDriver.runTest(TestDriver.java:640)
	at org.apache.hadoop.mrunit.TestDriver.runTest(TestDriver.java:627)
	at com.demo.sort.MaxTemperatureMapperTest.processValidRecord(MaxTemperatureMapperTest.java:35)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

我是从这里下载的：http://download.youkuaiyun.com/download/fkbush/9522361#comment

3.2 写UnitTest代码

单元测试函数的上面加上 @Test 注入标签。示例代码如下：

MaxTemperatureMapperTest.java

package com.demo.sort;

import java.io.IOException;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mrunit.mapreduce.MapDriver;
import org.junit.Test;

public final class MaxTemperatureMapperTest {

	@Test
	public void processValidRecord() throws IOException {
		final Text value = new Text("123456798676231190101234567986762311901012345679867623119010123456798676231190101234561+00121534567890356"
		/*
		 * +
		 * "\r\n123456798676231190101234567986762311901012345679867623119010123456798676231190101234562+01122934567890456"
		 * +
		 * "\r\n123456798676231190201234567986762311901012345679867623119010123456798676231190101234562+02120234567893456"
		 * +
		 * "\r\n123456798676231190401234567986762311901012345679867623119010123456798676231190101234561+00321234567803456"
		 * +
		 * "\r\n123456798676231190101234567986762311902012345679867623119010123456798676231190101234561+00429234567903456"
		 * +
		 * "\r\n123456798676231190501234567986762311902012345679867623119010123456798676231190101234561+01021134568903456"
		 * +
		 * "\r\n123456798676231190201234567986762311902012345679867623119010123456798676231190101234561+01124234578903456"
		 * +
		 * "\r\n123456798676231190301234567986762311905012345679867623119010123456798676231190101234561+04121234678903456"
		 * +
		 * "\r\n123456798676231190301234567986762311905012345679867623119010123456798676231190101234561+0082123567"
		 */);
		new MapDriver<LongWritable, Text, Text, IntWritable>().withMapper(new MaxTemperatureMapper()).withInput(new LongWritable(110000), value).withOutput(new Text("1901"), new IntWritable(11))
				.runTest();
	}
}

MaxTemperatureMapper.java

/**
* 页面描述
* @author Henry
* Created at 2017年7月23日
*/
package com.demo.sort;

import java.io.IOException;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

// 获得每年的温度值。
// 输入：一串文本。
// 输出：年份(字符范围：15-19)和温度（字符范围：87-2位，有可能有加号），当没有温度数据时，用-999代替。
public class MaxTemperatureMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
	int MISSED = 999;
	@Override
	protected void map(final LongWritable key, final Text value, final Mapper<LongWritable, Text, Text, IntWritable>.Context context) throws IOException, InterruptedException {
		final String line = value.toString();
		final String year = line.substring(15, 19);
		final char symbol = line.charAt(87);
		int airTemplate = -999;
		if (symbol == '+') {
			airTemplate = Integer.parseInt(line.substring(88, 92));
		} else {
			airTemplate = Integer.parseInt(line.substring(87, 92));
		}
		
		final String quality = line.substring(92, 93); // 空气质量指数
		if (airTemplate == MISSED && quality.matches("[01459]")) {
			context.write(new Text(year), new IntWritable(airTemplate));
		}
	}
}

3.3 运行结果

运行报错了！！可能是发布jar的作者缺少发布一个类了？有知道的朋友么？

java.lang.NoClassDefFoundError: org/powermock/api/mockito/PowerMockito
	at org.apache.hadoop.mrunit.mapreduce.MapDriver.run(MapDriver.java:147)
	at org.apache.hadoop.mrunit.TestDriver.runTest(TestDriver.java:640)
	at org.apache.hadoop.mrunit.TestDriver.runTest(TestDriver.java:627)
	at com.demo.sort.MaxTemperatureMapperTest.processValidRecord(MaxTemperatureMapperTest.java:35)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.ClassNotFoundException: org.powermock.api.mockito.PowerMockito
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 27 more

3.4 报错解决过程后续

为了避免繁琐的jar依赖关系，我决定采用Maven插件来管理jar。

项目结构如下：

pom.xml：

<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>practice.hadoop</groupId>
	<artifactId>simple-examples</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>simple-examples</name>
	<url>http://maven.apache.org</url>

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

	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-common -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-common</artifactId>
			<version>2.8.0</version>
		</dependency>

		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-hdfs</artifactId>
			<version>2.8.0</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-client -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-client</artifactId>
			<version>2.8.0</version>
		</dependency>

		<dependency>
			<groupId>org.apache.mrunit</groupId>
			<artifactId>mrunit</artifactId>
			<version>1.1.0</version>
			<classifier>hadoop2</classifier>
			<scope>test</scope>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-mapreduce-client-core -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-mapreduce-client-core</artifactId>
			<version>2.8.0</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-yarn-api -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-yarn-api</artifactId>
			<version>2.8.0</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-auth -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-auth</artifactId>
			<version>2.8.0</version>
		</dependency>

		<dependency>
			<groupId>jdk.tools</groupId>
			<artifactId>jdk.tools</artifactId>
			<version>1.8</version>
			<scope>system</scope>
			<systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-minicluster -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-minicluster</artifactId>
			<version>2.8.0</version>
			<scope>test</scope>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-mapreduce-client-jobclient -->
		<dependency>
			<groupId>org.apache.hadoop</groupId>
			<artifactId>hadoop-mapreduce-client-jobclient</artifactId>
			<version>2.8.0</version>
			<scope>provided</scope>
		</dependency>

	</dependencies>
</project>