java jdk1.8都可以了
注意jdk的路径要拷贝到一个没有空格的路径改掉JAVA_HOME系统环境变量
在etc/hadoop/hadoop_env.cmd里有设置%JAVA_HOME%了不用管，但是不支持带空格的路径，hadoop路径也不能有空格
首先：
配置输入和输出结果文件夹
- 添加和src目录同级的input文件夹到项目中
在input文件夹中放置一个或多个输入文件源
新建一个test.segmented文件
内容如下:
dfdfadgdgag
aadads
fudflcl
cckcer
fadf
dfdfadgdgag
fudflcl
fuck
fuck
fuckfuck
haha
aaa
- 配置运行参数
在Intellij菜单栏中选择Run->Edit Configurations，在弹出来的对话框中点击+，新建一个Application配置。配置Main class为WordCount（可以点击右边的...选择），
Program arguments为input/ output/，即输入路径为刚才创建的input文件夹，输出为output
另外我建议改下IDEA maven的镜像不然会很慢
修改方法：在~/.m2目录下的settings.xml文件中，（如果该文件不存在，则需要从maven/conf目录下拷贝一份），找到标签，添加如下子标签：
然后去对照一下IDEA里的maven目录与settings.xml文件目录
<mirror>
<id>alimaven</id>
<name>aliyun maven</name>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
<mirrorOf>central</mirrorOf>
</mirror>
pom.xml：
<?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>dsf</groupId>
<artifactId>dsff</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-mapreduce-client-core</artifactId>
<version>2.7.3</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.7.3</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-yarn-common</artifactId>
<version>2.7.3</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-common</artifactId>
<version>2.7.3</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<configuration>
<excludeTransitive>false</excludeTransitive>
<stripVersion>true</stripVersion>
<outputDirectory>./lib</outputDirectory>
</configuration>
</plugin>
</plugins>
</build>
</project>
- 新建一个WordCount.java文件
内容如下：
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
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;
public class WordCount {
public static class TokenizerMapper
extends Mapper<Object, Text, Text, IntWritable> {
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
public void map(Object key, Text value, Context context
) throws IOException, InterruptedException {
StringTokenizer itr = new StringTokenizer(value.toString());
while (itr.hasMoreTokens()) {
word.set(itr.nextToken());
context.write(word, one);
}
}
}
public static class IntSumReducer
extends Reducer<Text, IntWritable, Text, IntWritable> {
private IntWritable result = new IntWritable();
public void reduce(Text key, Iterable<IntWritable> values,
Context context
) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
result.set(sum);
context.write(key, result);
}
}
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
Job job = Job.getInstance(conf, "word count");
job.setJarByClass(WordCount.class);
job.setMapperClass(TokenizerMapper.class);
job.setCombinerClass(IntSumReducer.class);
job.setReducerClass(IntSumReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
- 然后要用windows可以看下教程：
这一定是可以的也是最方便的了
https://www.cs.helsinki.fi/u/jilu/paper/hadoop_on_win.pdf
首先下载hadoop二进制程序
2.7.3 source：
http://hadoop.apache.org/releases.html
替换掉hadoop-2.7.3里的bin文件
替换程序：
https://github.com/srccodes/hadoop-common-2.2.0-bin/archive/master.zip
设置环境：
这里注意下最好是在IDEA里设置HADOOP_HOME环境变量,如果设置的是系统环境变量那么你就还需要修改，我都设置了。。。
hadoop-2.7.3-srchadoop-common-projecthadoop-commonsrcmainjavaorgapachehadooputilShell.java
源码：
2.7.3 source：
http://hadoop.apache.org/releases.html
private static String checkHadoopHome() {
// first check the Dflag hadoop.home.dir with JVM scope
//System.setProperty("hadoop.home.dir", "...");
String home = System.getProperty("hadoop.home.dir");
// fall back to the system/user-global env variable
if (home == null) {
home = System.getenv("HADOOP_HOME");
}
try {
// couldn't find either setting for hadoop's home directory
if (home == null) {
throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");
}
if (home.startsWith(""") && home.endsWith(""")) {
home = home.substring(1, home.length()-1);
}
// check that the home setting is actually a directory that exists
File homedir = new File(home);
if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory()) {
throw new IOException("Hadoop home directory " + homedir
+ " does not exist, is not a directory, or is not an absolute path.");
}
home = homedir.getCanonicalPath();
} catch (IOException ioe) {
if (LOG.isDebugEnabled()) {
LOG.debug("Failed to detect a valid hadoop home directory", ioe);
}
home = null;
}
//固定本机的hadoop地址
home="D:\hadoop-2.7.3";
return home;
}
home = System.getenv("HADOOP_HOME");
如果是设置系统环境变量，这里获取的HADOOP_HOME的home目录的字符串会在字符串开始加入一个'u202A'字符，(好像是)代表c/c++/java源码(神奇)
然后把文件拷贝到你的工程下，idea会优先查找工程目录下的(可以先拷过来再改)
如果是设置IDEA里的环境变量就不用改Shell.java了
之后按照文档里的改下NativeIO.java文件
hadoop-2.7.3-srchadoop-common-projecthadoop-commonsrcmainjavaorgapachehadoopio
ativeioNativeIO.java
修改行609左右
return access0(path, desiredAccess.accessRight());
改成
return true;
也拷到工程下来就行了
另外建议以管理员模式打开IDEA
由于Hadoop的设定，下次运行时务必删除output文件夹！
好了,运行程序,结果如下:
aaa 1
aadads 1
cckcer 1
dfdfadgdgag 2
fadf 1
fuck 2
fuckfuck 1
fudflcl 2
haha 1