1，商城：是单商家，多买家的商城系统。数据库是mysql，语言java。

2，sqoop1.9.33：在mysql和hadoop中交换数据。

3，hadoop2.2.0：这里用于练习的是伪分布模式。

4，完毕内容：喜欢该商品的人还喜欢，同样购物喜好的好友推荐。

步骤：

1，通过sqoop从mysql中将 “用户收藏商品” （这里用的是用户收藏商品信息表作为推荐系统业务上的根据，业务根据能够非常复杂。这里主要介绍推荐系统的基本原理，所以推荐根据非常easy）的表数据导入到hdfs中。

2，用MapReduce实现推荐算法。

3，通过sqoop将推荐系统的结果写回mysql。

4，java商城通过推荐系统的数据实现<喜欢该商品的人还喜欢，同样购物喜好的好友推荐。>两个功能。

实现：

1，

推荐系统的数据来源：

左边是用户，右边是商品。用户每收藏一个商品都会生成一条这种信息，<喜欢该商品的人还喜欢，同样购物喜好的好友推荐。>的数据来源都是这张表。

sqoop导入数据，这里用的sqoop1.9.33。sqoop1.9.33的资料非常少，会出现一些错误，搜索不到的能够发到我的邮箱keepmovingzx@163.com。

创建链接信息

这个比較简单

创建job

信息填对就能够了

导入数据运行 start job --jid 上面创建成功后返回的ID

导入成功后的数据

2，eclipse开发MapReduce程序

ShopxxProductRecommend<喜欢该商品的人还喜欢>

整个项目分两部，一，以用户对商品进行分组，二，求出商品的同现矩阵。

一

  第1大步的数据为输入參数对商品进行分组

   输出參数：

  

二，以第一步的输出数据为输入求商品的同现矩阵

        输出数据

第一列数据为当前商品，第二列为与它相似的商品，第三列为相似率（越高越相似）。

整个过程就完了，以下

package xian.zhang.common;import java.util.regex.Pattern;public class Util {	 public static final Pattern DELIMITER = Pattern.compile("[\t,]");}

package xian.zhang.core;import java.io.IOException;import java.util.Iterator;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.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;/** * 将输入数据 userid1，product1  userid1，product2   userid1，product3 * 合并成 userid1 product1,product2,product3输出 * @author zx * */public class CombinProductInUser {		public static class CombinProductMapper extends Mapper
     
      {		@Override		protected void map(LongWritable key, Text value,Context context)				throws IOException, InterruptedException {			String[] items = value.toString().split(","); 			context.write(new IntWritable(Integer.parseInt(items[0])), new Text(items[1]));		}	}		public static class CombinProductReducer extends Reducer
      
       {		@Override		protected void reduce(IntWritable key, Iterable
       
         values,Context context)				throws IOException, InterruptedException {			StringBuffer sb = new StringBuffer();			Iterator
        
          it = values.iterator();			sb.append(it.next().toString());			while(it.hasNext()){				sb.append(",").append(it.next().toString());			}			context.write(key, new Text(sb.toString()));		}			}		@SuppressWarnings("deprecation")	public static boolean run(Path inPath,Path outPath) throws IOException, ClassNotFoundException, InterruptedException{				Configuration conf = new Configuration();		Job job = new Job(conf,"CombinProductInUser");				job.setJarByClass(CombinProductInUser.class);		job.setMapperClass(CombinProductMapper.class);		job.setReducerClass(CombinProductReducer.class);		job.setOutputKeyClass(IntWritable.class);		job.setOutputValueClass(Text.class);				FileInputFormat.addInputPath(job, inPath);		FileOutputFormat.setOutputPath(job, outPath);				return job.waitForCompletion(true);			}	}
        
       
      
     

package xian.zhang.core;import java.io.IOException;import java.util.Iterator;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.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;/** * 将输入数据 userid1，product1  userid1，product2   userid1，product3 * 合并成 userid1 product1,product2,product3输出 * @author zx * */public class CombinProductInUser {		public static class CombinProductMapper extends Mapper
     
      {		@Override		protected void map(LongWritable key, Text value,Context context)				throws IOException, InterruptedException {			String[] items = value.toString().split(","); 			context.write(new IntWritable(Integer.parseInt(items[0])), new Text(items[1]));		}	}		public static class CombinProductReducer extends Reducer
      
       {		@Override		protected void reduce(IntWritable key, Iterable
       
         values,Context context)				throws IOException, InterruptedException {			StringBuffer sb = new StringBuffer();			Iterator
        
          it = values.iterator();			sb.append(it.next().toString());			while(it.hasNext()){				sb.append(",").append(it.next().toString());			}			context.write(key, new Text(sb.toString()));		}			}		@SuppressWarnings("deprecation")	public static boolean run(Path inPath,Path outPath) throws IOException, ClassNotFoundException, InterruptedException{				Configuration conf = new Configuration();		Job job = new Job(conf,"CombinProductInUser");				job.setJarByClass(CombinProductInUser.class);		job.setMapperClass(CombinProductMapper.class);		job.setReducerClass(CombinProductReducer.class);		job.setOutputKeyClass(IntWritable.class);		job.setOutputValueClass(Text.class);				FileInputFormat.addInputPath(job, inPath);		FileOutputFormat.setOutputPath(job, outPath);				return job.waitForCompletion(true);			}	}
        
       
      
     

package xian.zhang.core;import java.io.IOException;import org.apache.hadoop.fs.Path;public class Main {		public static void main(String[] args) throws ClassNotFoundException, IOException, InterruptedException {				if(args.length < 2){			throw new IllegalArgumentException("要有两个參数，数据输入的路径和输出路径");		}				Path inPath1 = new Path(args[0]);		Path outPath1 = new Path(inPath1.getParent()+"/CombinProduct");				Path inPath2 = outPath1;		Path outPath2 = new Path(args[1]);				if(CombinProductInUser.run(inPath1, outPath1)){			System.exit(ProductCo_occurrenceMatrix.run(inPath2, outPath2)?0:1);		}	}	}

ShopxxUserRecommend<同样购物喜好的好友推荐>

整个项目分两部，一，以商品对用户进行分组，二，求出用户的同现矩阵。

原理和ShopxxProductRecommend一样

以下附上代码

package xian.zhang.common;import java.util.regex.Pattern;public class Util {	 public static final Pattern DELIMITER = Pattern.compile("[\t,]");}

package xian.zhang.core;import java.io.IOException;import java.util.Iterator;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.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;/** * 将输入数据 userid1，product1  userid1，product2   userid1，product3 * 合并成 productid1 user1,user2,user3输出 * @author zx * */public class CombinUserInProduct {		public static class CombinUserMapper extends Mapper
     
      {		@Override		protected void map(LongWritable key, Text value,Context context)				throws IOException, InterruptedException {			String[] items = value.toString().split(","); 			context.write(new IntWritable(Integer.parseInt(items[1])), new Text(items[0]));		}	}		public static class CombinUserReducer extends Reducer
      
       {		@Override		protected void reduce(IntWritable key, Iterable
       
         values,Context context)				throws IOException, InterruptedException {			StringBuffer sb = new StringBuffer();			Iterator
        
          it = values.iterator();			sb.append(it.next().toString());			while(it.hasNext()){				sb.append(",").append(it.next().toString());			}			context.write(key, new Text(sb.toString()));		}			}		@SuppressWarnings("deprecation")	public static boolean run(Path inPath,Path outPath) throws IOException, ClassNotFoundException, InterruptedException{		Configuration conf = new Configuration();		Job job = new Job(conf,"CombinUserInProduct");				job.setJarByClass(CombinUserInProduct.class);		job.setMapperClass(CombinUserMapper.class);		job.setReducerClass(CombinUserReducer.class);		job.setOutputKeyClass(IntWritable.class);		job.setOutputValueClass(Text.class);				FileInputFormat.addInputPath(job, inPath);		FileOutputFormat.setOutputPath(job, outPath);				return job.waitForCompletion(true);			}	}
        
       
      
     

package xian.zhang.core;import java.io.IOException;import java.util.Iterator;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.NullWritable;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 xian.zhang.common.Util;/** * 用户的同先矩阵 * @author zx * */public class UserCo_occurrenceMatrix {	public static class Co_occurrenceMapper extends Mapper
     
      {		IntWritable one = new IntWritable(1);				@Override		protected void map(LongWritable key, Text value, Context context)throws IOException, InterruptedException {						String[] products = Util.DELIMITER.split(value.toString());			for(int i=1;i
      
       {		NullWritable nullKey =NullWritable.get();				@Override		protected void reduce(Text key, Iterable
       
         values,Context context)				throws IOException, InterruptedException {			int sum = 0;			Iterator
        
          it = values.iterator();			while(it.hasNext()){				sum += it.next().get();			}			context.write(nullKey, new Text(key.toString().replace(":", ",") + "," + sum));		}			}		@SuppressWarnings("deprecation")	public static boolean run(Path inPath,Path outPath) throws IOException, ClassNotFoundException, InterruptedException{				Configuration conf = new Configuration();		Job job = new Job(conf,"UserCo_occurrenceMatrix");				job.setJarByClass(UserCo_occurrenceMatrix.class);		job.setMapperClass(Co_occurrenceMapper.class);		job.setReducerClass(Co_occurrenceReducer.class);		job.setMapOutputKeyClass(Text.class);		job.setMapOutputValueClass(IntWritable.class);				job.setOutputKeyClass(NullWritable.class);		job.setOutputKeyClass(Text.class);				FileInputFormat.addInputPath(job, inPath);		FileOutputFormat.setOutputPath(job, outPath);				return job.waitForCompletion(true);	}	}
        
       
      
     

package xian.zhang.core;import java.io.IOException;import org.apache.hadoop.fs.Path;public class Main {		public static void main(String[] args) throws ClassNotFoundException, IOException, InterruptedException {				if(args.length < 2){			throw new IllegalArgumentException("要有两个參数，数据输入的路径和输出路径");		}				Path inPath1 = new Path(args[0]);		Path outPath1 = new Path(inPath1.getParent()+"/CombinUser");				Path inPath2 = outPath1;		Path outPath2 = new Path(args[1]);				if(CombinUserInProduct.run(inPath1, outPath1)){			System.exit(UserCo_occurrenceMatrix.run(inPath2, outPath2)?0:1);		}	}	}

代码在github上有

git@github.com:chaoku/ShopxxProductRecommend.git