話不多說，直接上效果圖。
可以看到代碼是在集群上運行的而不是在本地。
而且我所說的自動不是其他博客說的那樣還要自己手動打jar包然后在eclipse中通過代碼傳到集群上，而是在eclipse上運行這段代碼會自動把jar包打好然后自動上傳到集群上
完全不用手！
完全不用手！
完全不用手！
非常方便！！！

示例

鏈接：https://pan.baidu.com/s/1KVvwsHLEI0CHdhiwcfIgww
提取碼：ahzp

這是一個倒排索引的例子，data是數據，InvertIndex是mapreduce代碼，EJob是自動打包工具。
代碼中的一些關鍵點我已經備注了，按照提示設置路徑就沒問題。
首先在eclipse中連接hadoop，可以參照我的博客，但是按照這樣運行是默認在本地運行的，運行時會顯示在localhost上運行，要想在集群上運行，需要把在搭建hadoop中的配置的那些文件復制到本項目的bin目錄下，像這樣，然后就可以提交到集群了。可以直接拿我這個代碼改一下路徑嘗試一下完全自動打包提交的快感。

代碼展示

InvertIndex的代碼（用來實現倒排索引的，很基礎，所以不過多說）：

package test;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
//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.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
import org.apache.hadoop.mapred.JobConf;


public class InvertIndex {
	

	public static class Map extends Mapper<LongWritable,Text,Text,Text>
	{
		
		@Override
		public void map(LongWritable key,Text value,Context context) throws IOException,InterruptedException 
		{
			FileSplit fileSplit = (FileSplit)context.getInputSplit();
			String fileName = fileSplit.getPath().getName();
			Text word = new Text();
//			System.out.println(fileName.toString());
			Text fileName_lineOffset = new Text(fileName);
			StringTokenizer itr = new StringTokenizer(value.toString());
			for(;itr.hasMoreTokens();){
				word.set(itr.nextToken());
				context.write(word, fileName_lineOffset);
			}
		}
	}

	public static class Reduce extends Reducer<Text,Text,Text,Text>
	{
		@Override
		public void reduce(Text key,Iterable<Text> values,Context context) throws IOException,InterruptedException 
		{
			Iterator<Text> it = values.iterator();
			StringBuilder all = new StringBuilder();
			if (it.hasNext()){
				all.append(it.next().toString());
				for(;it.hasNext();){
					all.append(";");
//					System.out.println(it.next());
					all.append(it.next().toString());
				}
				context.write(key, new Text(all.toString()));
			}
		}
	}

	public static void main(String[] args ) throws Exception
	{

		// 重點
		// 這部分就是自動打jar包的代碼，將需要打包的項目的bin目錄輸入，然后jar包會輸出到EJob中設置的輸出目錄中
		File jarFile = EJob.createTempJar("/root/workspace/Myproject/bin");
		System.out.println(jarFile);
		ClassLoader classLoader = EJob.getClassLoader();        
		Thread.currentThread().setContextClassLoader(classLoader);       
		// 重點

		Configuration conf = new Configuration(true);        


		String[] ars=new String[]{"hdfs://192.168.75.128:9000/data/","hdfs://192.168.75.128:9000/output/test"};
		String[] otherArgs=new GenericOptionsParser(conf,ars).getRemainingArgs();
		@SuppressWarnings("deprecation")
		Job job= Job.getInstance(conf,"invert index");
		

		// 將打成的jar包上傳到集群
		((JobConf) job.getConfiguration()).setJar(jarFile.toString());
		      
		job.setMapperClass(Map.class);          
		job.setReducerClass(Reduce.class);      

		job.setInputFormatClass(TextInputFormat.class);
		FileInputFormat.addInputPath(job,new Path(otherArgs[0]));
//		job.setOutputFormatClass(TextOutputFormat.class);
		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(Text.class);
		String time = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date());        
		FileOutputFormat.setOutputPath(job,new Path(otherArgs[1]+ time));
		System.out.println("Job Start!");
		if (job.waitForCompletion(true)) {            
			System.out.println("ok!");    
			System.exit(0); 
		} else {            
			System.out.println("error!");            
			System.exit(-1);        
	
		}
	}
}

EJob的代碼（這是個大佬寫的，真的非常好用，大體思路就是創建一個jar包，然后讀取bin目錄下文件將其寫入jar包中，然后直接將該jar包提交到集群上，實現完全自動打包提交。代碼中具體要改的我已經備注上去了，按照備注改就可以正常運行了）：

package test;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest; 

public class EJob {     
    
	private static List<URL> classPath = new ArrayList<URL>();     
    
    // 這里的輸入root是你要打jar包項目的bin目錄
	public static File createTempJar(String root) throws IOException { 
//		System.out.println("bbbb");
		if (!new File(root).exists()) {            
			return null;        
		}   
//		System.out.println("aaaa");
		Manifest manifest = new Manifest();        
		manifest.getMainAttributes().putValue("Manifest-Version", "1.0");        
		//final File jarFile = File.createTempFile("EJob-", ".jar", new File(System.getProperty("java.io.tmpdir")));  
		// 這個是你打成的jar包輸出的目錄       
		final File jarFile = File.createTempFile("EJob-", ".jar",new File("/root/workspace/Myproject/bin/zf/"));
		Runtime.getRuntime().addShutdownHook(new Thread() {            
			public void run() {                
				jarFile.delete();            
			}        
		});         

		JarOutputStream out = new JarOutputStream(new FileOutputStream(jarFile), manifest);        
		createTempJarInner(out, new File(root), "");        
		out.flush();        
		out.close();        
		return jarFile;    
	}     

	private static void createTempJarInner(JarOutputStream out, File f,String base) throws IOException{        
		if (f.isDirectory()) {            
			File[] fl = f.listFiles();            
			if (base.length() > 0) {                
				base = base + "/";            
			}            
			for (int i = 0; i < fl.length; i++) {                
				createTempJarInner(out, fl[i], base + fl[i].getName());            
			}        
		} else {            
			out.putNextEntry(new JarEntry(base));            
			FileInputStream in = new FileInputStream(f);            
			byte[] buffer = new byte[1024];            
			int n = in.read(buffer);            
			while (n != -1) {                
				out.write(buffer, 0, n);                
				n = in.read(buffer);            
			}            
			in.close();        
		}    
	}     

	public static ClassLoader getClassLoader() {        
		ClassLoader parent = Thread.currentThread().getContextClassLoader();         
		if (parent == null){            
			parent = EJob.class.getClassLoader();        
		}        
		if (parent == null) {            
			parent = ClassLoader.getSystemClassLoader();        
		}        
		return new URLClassLoader(classPath.toArray(new URL[0]), parent);    
	}     

	public static void addClasspath(String component) {         
		if ((component != null) && (component.length() > 0)) {            
			try {                
				File f = new File(component);                 
				if (f.exists()) {                    
					//URL key = f.getCanonicalFile().toURL();
					URL key = f.getCanonicalFile().toURI().toURL();
					if (!classPath.contains(key)) {                        
						classPath.add(key);                    
					}                
				}            
			}catch (IOException e) {            
			}        
		}    
	} 
}