我在ubuntu14.0.2o.s上运行hadoop2.7.0，并使用nano文本编辑器创建wordcount.java，源代码是从apachehadoop2.7.0文档复制的。
在我用这个命令编译wordcount.java之后 javac -classpath hadoop-2.7.0-core.jar -d MyJava wordcount.java ，以下是我收到的错误消息。
public class WordCount2 {
^
wordcount_v2.java:11: error: package org.apache.hadoop.conf does not exist
import org.apache.hadoop.conf.Configuration;
^
wordcount_v2.java:12: error: package org.apache.hadoop.fs does not exist
import org.apache.hadoop.fs.Path;
^
wordcount_v2.java:13: error: package org.apache.hadoop.io does not exist
import org.apache.hadoop.io.IntWritable;
^
wordcount_v2.java:14: error: package org.apache.hadoop.io does not exist
import org.apache.hadoop.io.Text;
^
wordcount_v2.java:15: error: package org.apache.hadoop.mapreduce does not exist
import org.apache.hadoop.mapreduce.Job;
^
wordcount_v2.java:16: error: package org.apache.hadoop.mapreduce does not exist
import org.apache.hadoop.mapreduce.Mapper;
^
wordcount_v2.java:17: error: package org.apache.hadoop.mapreduce does not exist
import org.apache.hadoop.mapreduce.Reducer;
^
wordcount_v2.java:18: error: package org.apache.hadoop.mapreduce.lib.input does not exist
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
^
wordcount_v2.java:19: error: package org.apache.hadoop.mapreduce.lib.output does not exist
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
^
wordcount_v2.java:20: error: package org.apache.hadoop.mapreduce does not exist
import org.apache.hadoop.mapreduce.Counter;
^
wordcount_v2.java:21: error: package org.apache.hadoop.util does not exist
import org.apache.hadoop.util.GenericOptionsParser;
^
wordcount_v2.java:22: error: package org.apache.hadoop.util does not exist
import org.apache.hadoop.util.StringUtils;
^
wordcount_v2.java:27: error: cannot find symbol
extends Mapper<Object, Text, Text, IntWritable>{
^
symbol: class Mapper
location: class WordCount2
wordcount_v2.java:27: error: cannot find symbol
extends Mapper<Object, Text, Text, IntWritable>{
^
symbol: class Text
location: class WordCount2
wordcount_v2.java:27: error: cannot find symbol
extends Mapper<Object, Text, Text, IntWritable>{
^
symbol: class Text
location: class WordCount2
wordcount_v2.java:27: error: cannot find symbol
extends Mapper<Object, Text, Text, IntWritable>{
^
symbol: class IntWritable
location: class WordCount2
wordcount_v2.java:31: error: cannot find symbol
private final static IntWritable one = new IntWritable(1);
^
symbol: class IntWritable
location: class TokenizerMapper
wordcount_v2.java:32: error: cannot find symbol
private Text word = new Text();
^
symbol: class Text
location: class TokenizerMapper
wordcount_v2.java:37: error: cannot find symbol
private Configuration conf;
^
symbol: class Configuration
location: class TokenizerMapper
wordcount_v2.java:41: error: cannot find symbol
public void setup(Context context) throws IOException,
^
symbol: class Context
location: class TokenizerMapper
wordcount_v2.java:69: error: cannot find symbol
public void map(Object key, Text value, Context context
^
symbol: class Text
location: class TokenizerMapper
wordcount_v2.java:69: error: cannot find symbol
public void map(Object key, Text value, Context context
^
symbol: class Context
location: class TokenizerMapper
wordcount_v2.java:88: error: cannot find symbol
extends Reducer<Text,IntWritable,Text,IntWritable> {
^
symbol: class Reducer
location: class WordCount2
wordcount_v2.java:88: error: cannot find symbol
extends Reducer<Text,IntWritable,Text,IntWritable> {
^
symbol: class Text
location: class WordCount2
wordcount_v2.java:88: error: cannot find symbol
extends Reducer<Text,IntWritable,Text,IntWritable> {
^
symbol: class IntWritable
location: class WordCount2
wordcount_v2.java:88: error: cannot find symbol
extends Reducer<Text,IntWritable,Text,IntWritable> {
^
symbol: class Text
location: class WordCount2
wordcount_v2.java:88: error: cannot find symbol
extends Reducer<Text,IntWritable,Text,IntWritable> {
^
symbol: class IntWritable
location: class WordCount2
wordcount_v2.java:89: error: cannot find symbol
private IntWritable result = new IntWritable();
^
symbol: class IntWritable
location: class IntSumReducer
wordcount_v2.java:91: error: cannot find symbol
public void reduce(Text key, Iterable<IntWritable> values,
^
symbol: class Text
location: class IntSumReducer
wordcount_v2.java:91: error: cannot find symbol
public void reduce(Text key, Iterable<IntWritable> values,
^
symbol: class IntWritable
location: class IntSumReducer
wordcount_v2.java:92: error: cannot find symbol
Context context
^
symbol: class Context
location: class IntSumReducer
wordcount_v2.java:31: error: cannot find symbol
private final static IntWritable one = new IntWritable(1);
^
symbol: class IntWritable
location: class TokenizerMapper
wordcount_v2.java:32: error: cannot find symbol
private Text word = new Text();
^
symbol: class Text
location: class TokenizerMapper
wordcount_v2.java:40: error: method does not override or implement a method from a supertype
@Override
^
wordcount_v2.java:46: error: cannot find symbol
URI[] patternsURIs = Job.getInstance(conf).getCacheFiles();
^
symbol: variable Job
location: class TokenizerMapper
wordcount_v2.java:48: error: cannot find symbol
Path patternsPath = new Path(patternsURI.getPath());
^
symbol: class Path
location: class TokenizerMapper
wordcount_v2.java:48: error: cannot find symbol
Path patternsPath = new Path(patternsURI.getPath());
^
symbol: class Path
location: class TokenizerMapper
wordcount_v2.java:64: error: cannot find symbol
+ StringUtils.stringifyException(ioe));
^
symbol: variable StringUtils
location: class TokenizerMapper
wordcount_v2.java:68: error: method does not override or implement a method from a supertype
@Override
^
wordcount_v2.java:80: error: cannot find symbol
Counter counter = context.getCounter(CountersEnum.class.getName(),
^
symbol: class Counter
location: class TokenizerMapper
wordcount_v2.java:89: error: cannot find symbol
private IntWritable result = new IntWritable();
^
symbol: class IntWritable
location: class IntSumReducer
wordcount_v2.java:95: error: cannot find symbol
for (IntWritable val : values) {
^
symbol: class IntWritable
location: class IntSumReducer
wordcount_v2.java:104: error: cannot find symbol
Configuration conf = new Configuration();
^
symbol: class Configuration
location: class WordCount2
wordcount_v2.java:104: error: cannot find symbol
Configuration conf = new Configuration();
^
symbol: class Configuration
location: class WordCount2
wordcount_v2.java:105: error: cannot find symbol
GenericOptionsParser optionParser = new GenericOptionsParser(conf, args);
^
symbol: class GenericOptionsParser
location: class WordCount2
wordcount_v2.java:105: error: cannot find symbol
GenericOptionsParser optionParser = new GenericOptionsParser(conf, args);
^
symbol: class GenericOptionsParser
location: class WordCount2
wordcount_v2.java:111: error: cannot find symbol
Job job = Job.getInstance(conf, "word count");
^
symbol: class Job
location: class WordCount2
wordcount_v2.java:111: error: cannot find symbol
Job job = Job.getInstance(conf, "word count");
^
symbol: variable Job
location: class WordCount2
wordcount_v2.java:116: error: cannot find symbol
job.setOutputKeyClass(Text.class);
^
symbol: class Text
location: class WordCount2
wordcount_v2.java:117: error: cannot find symbol
job.setOutputValueClass(IntWritable.class);
^
symbol: class IntWritable
location: class WordCount2
wordcount_v2.java:122: error: cannot find symbol
job.addCacheFile(new Path(remainingArgs[++i]).toUri());
^
symbol: class Path
location: class WordCount2
wordcount_v2.java:128: error: cannot find symbol
FileInputFormat.addInputPath(job, new Path(otherArgs.get(0)));
^
symbol: class Path
location: class WordCount2
wordcount_v2.java:128: error: cannot find symbol
FileInputFormat.addInputPath(job, new Path(otherArgs.get(0)));
^
symbol: variable FileInputFormat
location: class WordCount2
wordcount_v2.java:129: error: cannot find symbol
FileOutputFormat.setOutputPath(job, new Path(otherArgs.get(1)));
^
symbol: class Path
location: class WordCount2
wordcount_v2.java:129: error: cannot find symbol
FileOutputFormat.setOutputPath(job, new Path(otherArgs.get(1)));
^
symbol: variable FileOutputFormat
location: class WordCount2
56 errors我想知道怎么会这样。我的jdk版本是1.8.0\u45
6条答案
按热度按时间nkoocmlb1#
使用maven进行依赖关系管理。你想在这里做的事情是在地狱世界的水平。
请参阅以下链接，为hadoop项目设置maven:maven for hadoop
brjng4g32#
这不是执行hadoop map reduce程序的正确方法首先您必须安装hadoop并在这个链接上配置安装指南http://www.bogotobogo.com/hadoop/bigdata_hadoop_install_on_ubuntu_single_node_cluster.php
之后这是字数计算的例子
第1部分http://www.bogotobogo.com/hadoop/bigdata_hadoop_creating_java_wordcount_project_with_eclipse_mapreduce2.php
第二部分http://www.bogotobogo.com/hadoop/bigdata_hadoop_creating_java_wordcount_project_with_eclipse_mapreduce2_part2.php
按照所有的指令一步一步地…然后你的程序将执行。。
58wvjzkj3#
这些错误是由于依赖关系造成的，您应该再添加几个库来编译而不会出现问题。图书馆可以在
HADOOP_HOME子目录，如~/share/hadoop/6psbrbz94#
只是为了补充信息，因为有些参考资料是关于hadoop的旧版本。
maven极大地简化了对引用的管理。您需要：
至少。祝你好运！
pzfprimi5#
不需要下载任何较旧版本的jar文件。你应该像这样运行命令
p、 s.注意类路径前后的平铺字符（tab上的一个键，左至1）。
bnl4lu3b6#
您还没有在代码中导入那些将要发生错误的类。
我想你得补充一点
hadoop-core-1.0.4.jar将所有这些类导入到您的代码中并再次编译，它应该可以工作。你可以接受任何版本
hadoop-core-x.y.z.jar它不是特定于hadoop-core-1.0.4.jar只是。