hadoop之mapreduce编程实例(系统日志初步清洗过滤处理)

刚刚开始接触hadoop的时候，总觉得必须要先安装hadoop集群才能开始学习MR编程，其实并不用这样，当然如果你有条件有机器那最好是自己安装配置一个hadoop集群，这样你会更容易理解其工作原理。我们今天就是要给大家演示如何不用安装hadoop直接调试编程MapReduce函数。

开始之前我们先来理解一下mapreduce的工作原理：

hadoop集群是有DataNode和NameNode两种节点构成，DataNode负责存储数据本身而NameNode负责存储数据的元数据信息，在启动mapreduce任务时，数据首先是通过inputformat模块从集群的文件库中读出，然后按照设定的Splitsize进行Split（默认是一个block大小128MB），通过ReadRecorder（RR）将每个split的数据块按行进行轮询访问结果给到map函数，由map函数按照编程的代码逻辑进行处理，输出key和value。由map到reduce的处理过程中包含三件事情，Combiner（map端的预先处理，相对于map段reduce）Partitioner（负责将map输出数据均衡的分配给reduce）Shulffling&&sort(根据map输出的key进行洗牌和排序，将结果根据partitioner的分配情况传输给指定的reduce)，最后reduce按照代码逻辑处理输出结果（也是key,value格式）。

注意：

map阶段的key-value对的格式是由输入的格式所决定的，如果是默认的TextInputFormat，则每行作为一个记录进程处理，其中key为此行的开头相对于文件的起始位置，value就是此行的字符文本
map阶段的输出的key-value对的格式必须同reduce阶段的输入key-value对的格式相对应

下面是wordcount的处理过程大家来理解一下：

现在我们开始我们的本地MR编程吧

首先我们得去官网下载一个hadoop安装包（本文用的hadoop2.6.0版本，不用安装，我们只要包中jars）

下载链接：https://archive.apache.org/dist/hadoop/common/（下载最多的那个就可以了，版本自己选个）

下面就上MR的代码吧：

[java] view plain copy
 
  1. package loganalysis;  
  2. import java.io.IOException;  
  3. import java.util.StringTokenizer;  
  4. import java.lang.*;  
  5.    
  6. import org.apache.hadoop.conf.Configuration;  
  7. import org.apache.hadoop.fs.Path;  
  8. import org.apache.hadoop.io.IntWritable;  
  9. import org.apache.hadoop.io.Text;  
  10. import org.apache.hadoop.mapreduce.Job;  
  11. import org.apache.hadoop.mapreduce.Mapper;  
  12. import org.apache.hadoop.mapreduce.Reducer;  
  13. import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;  
  14. import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;  
  15. import org.apache.hadoop.util.GenericOptionsParser;  
  16.   
  17.    
  18. public class WordCount {  
  19.    
  20.   public static class TokenizerMapper   
  21.        extends Mapper<Object, Text, Text, IntWritable>{  
  22.    
  23.     private final static IntWritable one = new IntWritable(1);  
  24.     private Text word = new Text();  
  25.     private String imei = new String();  
  26.     private String areacode  = new String();  
  27.     private String responsedata = new String();  
  28.     private String requesttime = new String();  
  29.     private String requestip = new String();  
  30.   
  31. //    map阶段的key-value对的格式是由输入的格式所决定的，如果是默认的TextInputFormat，则每行作为一个记录进程处理，其中key为此行的开头相对于文件的起始位置，value就是此行的字符文本  
  32. //    map阶段的输出的key-value对的格式必须同reduce阶段的输入key-value对的格式相对应  
  33.     public void map(Object key, Text value, Context context  
  34.                     ) throws IOException, InterruptedException {  
  35.       //StringTokenizer itr = new StringTokenizer(value.toString());  
  36.         
  37.       int areai = value.toString().indexOf("areacode", 21);  
  38.       int imeii = value.toString().indexOf("imei", 21);  
  39.       int redatai = value.toString().indexOf("responsedata", 21);  
  40.       int retimei = value.toString().indexOf("requesttime", 21);  
  41.       int reipi = value.toString().indexOf("requestip", 21);  
  42.         
  43.       if (areai==-1)  
  44.       { areacode=""; }  
  45.       else  
  46.       {  
  47.       areacode=value.toString().substring(areai+11);  
  48.       int len2=areacode.indexOf(""");  
  49.       if(len2 <= 1)  
  50.         {  
  51.           areacode="";  
  52.         }  
  53.       else   
  54.         {  
  55.           areacode=areacode.substring(0,len2);  
  56.         }  
  57.         
  58.       }  
  59.       if (imeii==-1)  
  60.       { imei=""; }  
  61.       else  
  62.       {  
  63.           imei=value.toString().substring(imeii+9);  
  64.       int len2=imei.indexOf("\");  
  65.       if(len2 <= 1)  
  66.         {  
  67.           imei="";  
  68.         }  
  69.       else   
  70.         {  
  71.           imei=imei.substring(0,len2);  
  72.         }  
  73.         
  74.       }  
  75.        
  76.         
  77.       if (redatai==-1)  
  78.       { responsedata=""; }  
  79.       else  
  80.       {  
  81.           responsedata=value.toString().substring(redatai+15);  
  82.       int len2=responsedata.indexOf(""");  
  83.       if(len2 <= 1)  
  84.         {  
  85.           responsedata="";  
  86.         }  
  87.       else   
  88.         {  
  89.           responsedata=responsedata.substring(0,len2);  
  90.         }  
  91.         
  92.       }  
  93.         
  94.         
  95.       if (retimei==-1)  
  96.       { requesttime=""; }  
  97.       else  
  98.       {  
  99.           requesttime=value.toString().substring(retimei+14);  
  100.       int len2=requesttime.indexOf(""");  
  101.       if(len2 <= 1)  
  102.         {  
  103.           requesttime="";  
  104.         }  
  105.       else   
  106.         {  
  107.           requesttime=requesttime.substring(0,len2);  
  108.         }  
  109.         
  110.       }  
  111.         
  112.       if (reipi==-1)  
  113.       { requestip=""; }  
  114.       else  
  115.       {  
  116.           requestip=value.toString().substring(reipi+12);  
  117.       int len2=requestip.indexOf(""");  
  118.       if(len2 <= 1)  
  119.         {  
  120.           requestip="";  
  121.         }  
  122.       else   
  123.         {  
  124.           requestip=requestip.substring(0,len2);  
  125.         }  
  126.         
  127.       }  
  128.      /* while (itr.hasMoreTokens()) { 
  129.           string tim; 
  130.            
  131.         word.set(itr.nextToken()); 
  132.         context.write(word, one); 
  133.       }*/  
  134.      if(imei!=""&&areacode!=""&&responsedata!=""&&requesttime!=""&&requestip!="")  
  135.      {  
  136.        String wd=new String();  
  137.        wd=imei+" "+areacode+" "+responsedata+" "+requesttime+" "+requestip;  
  138.        //wd="areacode|"+areacode +"|imei|"+ imei +"|responsedata|"+ responsedata +"|requesttime|"+ requesttime +"|requestip|"+ requestip;  
  139.        word.set(wd);  
  140.        context.write(word, one);  
  141.      }  
  142.   
  143.     }  
  144.   }  
  145.    
  146.   public static class IntSumReducer   
  147.        extends Reducer<Text,IntWritable,Text,IntWritable> {  
  148.     private IntWritable result = new IntWritable();  
  149.    
  150.     public void reduce(Text key, Iterable<IntWritable> values,   
  151.                        Context context  
  152.                        ) throws IOException, InterruptedException {  
  153.       int sum = 0;  
  154.       for (IntWritable val : values) {  
  155.         sum += val.get();  
  156.       }  
  157.       result.set(sum);  
  158.       context.write(key, result);  
  159.     }  
  160.   }  
  161.    
  162.   public static void main(String[] args) throws Exception {  
  163.     Configuration conf = new Configuration();  
  164.   //  String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();  
  165.     String[] otherArgs=new String[]{"/Users/mac/tmp/inputmr","/Users/mac/tmp/output1"};  
  166.       
  167.     if (otherArgs.length != 2) {  
  168.       System.err.println("Usage: wordcount <in> <out>");  
  169.       System.exit(2);  
  170.     }  
  171.       
  172.     //Job job = new Job(conf, "word count");  
  173.     Job job = Job.getInstance(conf);  
  174.       
  175.     job.setJarByClass(WordCount.class);  
  176.     job.setMapperClass(TokenizerMapper.class);  
  177.     job.setCombinerClass(IntSumReducer.class);  
  178.     job.setReducerClass(IntSumReducer.class);  
  179.     job.setOutputKeyClass(Text.class);  
  180.     job.setOutputValueClass(IntWritable.class);  
  181.     FileInputFormat.addInputPath(job, new Path(otherArgs[0]));  
  182.     FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));  
  183.     System.exit(job.waitForCompletion(true) ? 0 : 1);  
  184.   }  
  185. }  

主要以上除了jdk1.7其他的jar包都来自hadoop安装包中的share文件下下面

如果你不知道那些包需要那就将sharehadoop下面的所以得jar包都添加到项目中

注意：我的电脑是mac pro如果你的是Windows机器相关的路径需要修改一下，前面加上“file:///”（ file:///D: mpinput file:///D: mpoutput)

 String[] otherArgs=new String[]{"file:///D: mpinput","file:///D: mpoutput"};
这个程序核心代码都是在map中，主要做了系统日志中相关核心字段的提取并拼接以key形式返回给reduce，value都是设置为1，是为了方便以后的统计。因为是实例所以简单的弄了几个字段，实际可不止这些。

下面给下测试的系统日志：

[html] view plain copy
 
  1. 2016-04-18 16:00:00 {"areacode":"浙江省丽水市","countAll":0,"countCorrect":0,"datatime":"4134362","logid":"201604181600001184409476","requestinfo":"{"sign":"4","timestamp":"1460966390499","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"100","imei":"12345678900987654321","subjectNum":"13989589062","imsi":"12345678900987654321","queryNum":"13989589062"}","requestip":"36.16.128.234","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  2. 2016-04-18 16:00:00 {"areacode":"宁夏银川市","countAll":0,"countCorrect":0,"datatime":"4715990","logid":"201604181600001858043208","requestinfo":"{"sign":"4","timestamp":"1460966400120","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"1210","imei":"A0000044ABFD25","subjectNum":"15379681917","imsi":"460036951451601","queryNum":""}","requestip":"115.168.93.87","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果","userAgent":"ZTE-Me/Mobile"}  
  3. 2016-04-18 16:00:00 {"areacode":"黑龙江省哈尔滨市","countAll":0,"countCorrect":0,"datatime":"5369561","logid":"201604181600001068429609","requestinfo":"{"interfaceUserName":"12345678900987654321","queryNum":"","timestamp":"1460966400139","sign":"4","imsi":"460030301212545","imei":"35460207765269","subjectNum":"55588237","subjectPro":"123456","remark":"4","channelno":"2100"}","requestip":"42.184.41.180","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  4. 2016-04-18 16:00:00 {"areacode":"浙江省丽水市","countAll":0,"countCorrect":0,"datatime":"4003096","logid":"201604181600001648238807","requestinfo":"{"sign":"4","timestamp":"1460966391025","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"100","imei":"12345678900987654321","subjectNum":"13989589062","imsi":"12345678900987654321","queryNum":"13989589062"}","requestip":"36.16.128.234","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  5. 2016-04-18 16:00:00 {"areacode":"广西南宁市","countAll":0,"countCorrect":0,"datatime":"4047993","logid":"201604181600001570024205","requestinfo":"{"sign":"4","timestamp":"1460966382871","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"1006","imei":"A000004853168C","subjectNum":"07765232589","imsi":"460031210400007","queryNum":"13317810717"}","requestip":"219.159.72.3","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  6. 2016-04-18 16:00:00 {"areacode":"海南省五指山市","countAll":0,"countCorrect":0,"datatime":"5164117","logid":"201604181600001227842048","requestinfo":"{"sign":"4","timestamp":"1460966399159","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"1017","imei":"A000005543AFB7","subjectNum":"089836329061","imsi":"460036380954376","queryNum":"13389875751"}","requestip":"140.240.171.71","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  7. 2016-04-18 16:00:00 {"areacode":"山西省","countAll":0,"countCorrect":0,"datatime":"14075772","logid":"201604181600001284030648","requestinfo":"{"sign":"4","timestamp":"1460966400332","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"1006","imei":"A000004FE0218A","subjectNum":"03514043633","imsi":"460037471517070","queryNum":""}","requestip":"1.68.5.227","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  8. 2016-04-18 16:00:00 {"areacode":"四川省","countAll":0,"countCorrect":0,"datatime":"6270982","logid":"201604181600001173504863","requestinfo":"{"sign":"4","timestamp":"1460966398896","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"100","imei":"12345678900987654321","subjectNum":"13666231300","imsi":"12345678900987654321","queryNum":"13666231300"}","requestip":"182.144.66.97","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  
  9. 2016-04-18 16:00:00 {"areacode":"浙江省","countAll":0,"countCorrect":0,"datatime":"4198522","logid":"201604181600001390637240","requestinfo":"{"sign":"4","timestamp":"1460966399464","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"100","imei":"12345678900987654321","subjectNum":"05533876327","imsi":"12345678900987654321","queryNum":"05533876327"}","requestip":"36.23.9.49","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"000000","responsedata":"操作成功"}  
  10. 2016-04-18 16:00:00 {"areacode":"江苏省连云港市","countAll":0,"countCorrect":0,"datatime":"4408097","logid":"201604181600001249944032","requestinfo":"{"sign":"4","timestamp":"1460966395908","remark":"4","subjectPro":"123456","interfaceUserName":"12345678900987654321","channelno":"100","imei":"12345678900987654321","subjectNum":"18361451463","imsi":"12345678900987654321","queryNum":"18361451463"}","requestip":"58.223.4.210","requesttime":"2016-04-18 16:00:00","requesttype":"0","responsecode":"010005","responsedata":"无查询结果"}  


最后给出运行结果截图：

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原文地址：https://www.cnblogs.com/gaochsh/p/7803090.html