問題描述：練習(xí)寫了一個mapReduce的程序，運行報錯如下，因為是初學(xué)不知道該怎么解決，先是在網(wǎng)上找了很多，但是都一一排除了原因，目前還沒有解決的，源碼已經(jīng)貼在下面，求大神指導(dǎo)！代碼目的：統(tǒng)計hello文件中各個單詞出現(xiàn)的次數(shù)報錯信息如下：/opt/jdk1.8.0_191/bin/java?-javaagent:/opt/idea-IC-182.4892.20/lib/idea_rt.jar=39521:/opt/idea-IC-182.4892.20/bin?-Dfile.encoding=UTF-8?-classpath?/opt/jdk1.8.0_191/jre/lib/charsets.jar:/opt/jdk1.8.0_191/jre/lib/deploy.jar:/opt/jdk1.8.0_191/jre/lib/ext/cldrdata.jar:/opt/jdk1.8.0_191/jre/lib/ext/dnsns.jar:/opt/jdk1.8.0_191/jre/lib/ext/jaccess.jar:/opt/jdk1.8.0_191/jre/lib/ext/jfxrt.jar:/opt/jdk1.8.0_191/jre/lib/ext/localedata.jar:/opt/jdk1.8.0_191/jre/lib/ext/nashorn.jar:/opt/jdk1.8.0_191/jre/lib/ext/sunec.jar:/opt/jdk1.8.0_191/jre/lib/ext/sunjce_provider.jar:/opt/jdk1.8.0_191/jre/lib/ext/sunpkcs11.jar:/opt/jdk1.8.0_191/jre/lib/ext/zipfs.jar:/opt/jdk1.8.0_191/jre/lib/javaws.jar:/opt/jdk1.8.0_191/jre/lib/jce.jar:/opt/jdk1.8.0_191/jre/lib/jfr.jar:/opt/jdk1.8.0_191/jre/lib/jfxswt.jar:/opt/jdk1.8.0_191/jre/lib/jsse.jar:/opt/jdk1.8.0_191/jre/lib/management-agent.jar:/opt/jdk1.8.0_191/jre/lib/plugin.jar:/opt/jdk1.8.0_191/jre/lib/resources.jar:/opt/jdk1.8.0_191/jre/lib/rt.jar:/home/user/workspaces/practice/mysecondmapreduce/out/production/mysecondmapreduce:/home/user/下載/hadoop-2.7.2/share/hadoop/common/hadoop-nfs-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/hadoop-common-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/hadoop-common-2.7.2-tests.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/xz-1.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/asm-3.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/avro-1.7.4.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/gson-2.2.4.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/junit-4.11.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jsch-0.1.42.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jsp-api-2.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/xmlenc-0.52.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/guava-11.0.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jets3t-0.9.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jettison-1.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jetty-6.1.26.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jsr305-3.0.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/log4j-1.2.17.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/paranamer-2.3.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/activation-1.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-io-2.4.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/httpcore-4.2.5.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jaxb-api-2.2.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/stax-api-1.0-2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-cli-1.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-net-3.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jersey-core-1.9.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jersey-json-1.9.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/servlet-api-2.5.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/zookeeper-3.4.6.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-lang-2.6.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/httpclient-4.2.5.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/slf4j-api-1.7.10.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-codec-1.4.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/hadoop-auth-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/hamcrest-core-1.3.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jackson-xc-1.9.13.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jaxb-impl-2.2.3-1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jersey-server-1.9.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jetty-util-6.1.26.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/mockito-all-1.8.5.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/netty-3.6.2.Final.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/api-util-1.0.0-M20.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-math3-3.1.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/java-xmlbuilder-0.4.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/protobuf-java-2.5.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/snappy-java-1.0.4.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-digester-1.8.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/curator-client-2.7.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jackson-jaxrs-1.9.13.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-logging-1.1.3.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/curator-recipes-2.7.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/api-asn1-api-1.0.0-M20.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-compress-1.4.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-httpclient-3.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/apacheds-i18n-2.0.0-M15.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-beanutils-1.7.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/curator-framework-2.7.1.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jackson-core-asl-1.9.13.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/hadoop-annotations-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-collections-3.2.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-configuration-1.6.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/jackson-mapper-asl-1.9.13.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/commons-beanutils-core-1.8.0.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/htrace-core-3.1.0-incubating.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/common/lib/apacheds-kerberos-codec-2.0.0-M15.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/hdfs/hadoop-hdfs-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/hdfs/hadoop-hdfs-nfs-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/hdfs/hadoop-hdfs-2.7.2-tests.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-hs-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-app-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-core-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-common-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-shuffle-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-hs-plugins-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/mapreduce/hadoop-mapreduce-client-jobclient-2.7.2-tests.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-api-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-client-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-common-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-registry-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-tests-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-common-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-web-proxy-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-nodemanager-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-resourcemanager-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-sharedcachemanager-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-applications-distributedshell-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-server-applicationhistoryservice-2.7.2.jar:/home/user/下載/hadoop-2.7.2/share/hadoop/yarn/hadoop-yarn-applications-unmanaged-am-launcher-2.7.2.jar?mapreduce.WordCount 2019-01-18?17:01:58,772?WARN??[main]?util.NativeCodeLoader?(NativeCodeLoader.java:<clinit>(62))?-?Unable?to?load?native-hadoop?library?for?your?platform...?using?builtin-java?classes?where?applicable 2019-01-18?17:01:59,103?INFO??[main]?Configuration.deprecation?(Configuration.java:warnOnceIfDeprecated(1173))?-?session.id?is?deprecated.?Instead,?use?dfs.metrics.session-id 2019-01-18?17:01:59,104?INFO??[main]?jvm.JvmMetrics?(JvmMetrics.java:init(76))?-?Initializing?JVM?Metrics?with?processName=JobTracker,?sessionId= 2019-01-18?17:01:59,891?WARN??[main]?mapreduce.JobResourceUploader?(JobResourceUploader.java:uploadFiles(64))?-?Hadoop?command-line?option?parsing?not?performed.?Implement?the?Tool?interface?and?execute?your?application?with?ToolRunner?to?remedy?this. 2019-01-18?17:01:59,915?WARN??[main]?mapreduce.JobResourceUploader?(JobResourceUploader.java:uploadFiles(171))?-?No?job?jar?file?set.??User?classes?may?not?be?found.?See?Job?or?Job#setJar(String). 2019-01-18?17:01:59,925?INFO??[main]?input.FileInputFormat?(FileInputFormat.java:listStatus(283))?-?Total?input?paths?to?process?:?1 2019-01-18?17:02:00,025?INFO??[main]?mapreduce.JobSubmitter?(JobSubmitter.java:submitJobInternal(198))?-?number?of?splits:1 2019-01-18?17:02:00,236?INFO??[main]?mapreduce.JobSubmitter?(JobSubmitter.java:printTokens(287))?-?Submitting?tokens?for?job:?job_local1743862088_0001 2019-01-18?17:02:00,792?INFO??[main]?mapreduce.Job?(Job.java:submit(1294))?-?The?url?to?track?the?job:?http://localhost:8080/ 2019-01-18?17:02:00,793?INFO??[main]?mapreduce.Job?(Job.java:monitorAndPrintJob(1339))?-?Running?job:?job_local1743862088_0001 2019-01-18?17:02:00,794?INFO??[Thread-14]?mapred.LocalJobRunner?(LocalJobRunner.java:createOutputCommitter(471))?-?OutputCommitter?set?in?config?null 2019-01-18?17:02:00,798?INFO??[Thread-14]?output.FileOutputCommitter?(FileOutputCommitter.java:<init>(100))?-?File?Output?Committer?Algorithm?version?is?1 2019-01-18?17:02:00,802?INFO??[Thread-14]?mapred.LocalJobRunner?(LocalJobRunner.java:createOutputCommitter(489))?-?OutputCommitter?is?org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter 2019-01-18?17:02:00,924?INFO??[Thread-14]?mapred.LocalJobRunner?(LocalJobRunner.java:runTasks(448))?-?Waiting?for?map?tasks 2019-01-18?17:02:00,926?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.LocalJobRunner?(LocalJobRunner.java:run(224))?-?Starting?task:?attempt_local1743862088_0001_m_000000_0 2019-01-18?17:02:01,007?INFO??[LocalJobRunner?Map?Task?Executor?#0]?output.FileOutputCommitter?(FileOutputCommitter.java:<init>(100))?-?File?Output?Committer?Algorithm?version?is?1 2019-01-18?17:02:01,037?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.Task?(Task.java:initialize(612))?-??Using?ResourceCalculatorProcessTree?:?[?] 2019-01-18?17:02:01,045?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:runNewMapper(756))?-?Processing?split:?file:/home/user/project/hello:0+19 2019-01-18?17:02:01,170?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:setEquator(1205))?-?(EQUATOR)?0?kvi?26214396(104857584) 2019-01-18?17:02:01,170?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:init(998))?-?mapreduce.task.io.sort.mb:?100 2019-01-18?17:02:01,171?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:init(999))?-?soft?limit?at?83886080 2019-01-18?17:02:01,171?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:init(1000))?-?bufstart?=?0;?bufvoid?=?104857600 2019-01-18?17:02:01,171?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:init(1001))?-?kvstart?=?26214396;?length?=?6553600 2019-01-18?17:02:01,184?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:createSortingCollector(403))?-?Map?output?collector?class?=?org.apache.hadoop.mapred.MapTask$MapOutputBuffer 2019-01-18?17:02:01,187?INFO??[LocalJobRunner?Map?Task?Executor?#0]?mapred.MapTask?(MapTask.java:flush(1460))?-?Starting?flush?of?map?output 2019-01-18?17:02:01,196?INFO??[Thread-14]?mapred.LocalJobRunner?(LocalJobRunner.java:runTasks(456))?-?map?task?executor?complete. 2019-01-18?17:02:01,197?WARN??[Thread-14]?mapred.LocalJobRunner?(LocalJobRunner.java:run(560))?-?job_local1743862088_0001 java.lang.Exception:?java.io.IOException:?Type?mismatch?in?key?from?map:?expected?org.apache.hadoop.io.Text,?received?org.apache.hadoop.io.LongWritable ????at?org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462) ????at?org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522) Caused?by:?java.io.IOException:?Type?mismatch?in?key?from?map:?expected?org.apache.hadoop.io.Text,?received?org.apache.hadoop.io.LongWritable ????at?org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:1072) ????at?org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:715) ????at?org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl.write(TaskInputOutputContextImpl.java:89) ????at?org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.write(WrappedMapper.java:112) ????at?org.apache.hadoop.mapreduce.Mapper.map(Mapper.java:125) ????at?mapreduce.WordCount$WordCountMapper.map(WordCount.java:21) ????at?mapreduce.WordCount$WordCountMapper.map(WordCount.java:18) ????at?org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:146) ????at?org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787) ????at?org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) ????at?org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243) ????at?java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ????at?java.util.concurrent.FutureTask.run(FutureTask.java:266) ????at?java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ????at?java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ????at?java.lang.Thread.run(Thread.java:748) 2019-01-18?17:02:01,794?INFO??[main]?mapreduce.Job?(Job.java:monitorAndPrintJob(1360))?-?Job?job_local1743862088_0001?running?in?uber?mode?:?false 2019-01-18?17:02:01,795?INFO??[main]?mapreduce.Job?(Job.java:monitorAndPrintJob(1367))?-??map?0%?reduce?0% 2019-01-18?17:02:01,797?INFO??[main]?mapreduce.Job?(Job.java:monitorAndPrintJob(1380))?-?Job?job_local1743862088_0001?failed?with?state?FAILED?due?to:?NA 2019-01-18?17:02:01,802?INFO??[main]?mapreduce.Job?(Job.java:monitorAndPrintJob(1385))?-?Counters:?0 Process?finished?with?exit?code?0源碼如下：package?mapreduce; import?org.apache.hadoop.conf.Configuration; import?org.apache.hadoop.fs.Path; import?org.apache.hadoop.io.LongWritable; import?org.apache.hadoop.io.Text; 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.output.FileOutputFormat; import?java.io.IOException; public?class?WordCount?{ ????//?Hadoop中特帶的兩種類型,Text和LongWritable ????public?static?class?WordCountMapper?extends?Mapper<LongWritable,Text,Text,LongWritable>{ ????????@Override ????????protected?void?map(LongWritable?key,Text?value,Context?context)?throws?IOException,?InterruptedException?{ ????????????super.map(key,value,context); ????????????//?這里的value是Text類型的，而split方法是針對string類型的，所以這里先進行類型轉(zhuǎn)換再split操作 ????????????String[]?splits=value.toString().split("\\s"); ????????????for?(String?word:splits)?{ ????????????????//?遍歷一行中的每個單詞，出現(xiàn)次數(shù)記為1 ????????????????context.write(new?Text(word),new?LongWritable(1)); ????????????} ????????} ????} ????public?static?class?WordCountReducer?extends?Reducer<Text,LongWritable,Text,LongWritable>{ ????????@Override ????????protected?void?reduce(Text?word,?Iterable<LongWritable>?times,?Context?context)?throws?IOException,?InterruptedException?{ ????????????super.reduce(word,?times,?context); ????????????long?sum=0L; ????????????for?(LongWritable?time:times)?{ ????????????????//?記?。簩ongWritable轉(zhuǎn)換成long型再進行計算 ????????????????sum+=time.get(); ????????????} ????????????context.write(word,new?LongWritable(sum)); ????????} ????} ????public?static?void?main(String[]?args)?throws?Exception{ ????????//?記住:新建一個configuration對象,導(dǎo)入的包是：org.apache.hadoop.conf.Configuration ????????Configuration?conf=new?Configuration(); ????????//?new一個Job對象 ????????Job?job=new?Job(conf); ????????//?創(chuàng)建Job名稱 ????????job.setJobName(WordCountApp.class.getSimpleName()); ????????job.setJarByClass(WordCountApp.class); ????????//?創(chuàng)建Map，Reduce和打包 ????????job.setMapperClass(WordCountMapper.class); ????????job.setReducerClass(WordCountReducer.class); ????????//?記住：reduce輸出的類型一定要設(shè)置 ????????job.setOutputKeyClass(Text.class); ????????job.setOutputValueClass(LongWritable.class); ????????//?設(shè)置輸入、輸出路徑 ????????FileInputFormat.addInputPaths(job,"/home/user/project/hello"); ????????FileOutputFormat.setOutputPath(job,new?Path("/home/user/project/out")); ????????//?等待程序運行完，提交代碼到y(tǒng)arn上 ????????job.waitForCompletion(true); ????} }hello文件如下：hello????you hello????me