好友推荐的案例, 需要两个job, 第一个进行好友关系度计算, 第二个job将计算的关系进行推荐
1, fof关系类
package com.wenbronk.friend;import org.apache.hadoop.io.Text;/** * 定义fof关系 * @author root * */public class Fof extends Text{ public Fof() { super(); } /**' * 不论谁在前,返回一致的顺序 * @param a * @param b */ public Fof(String a, String b) { super(getFof(a, b)); } /** * 按字典顺序排序, 保证两个fof为同一组输出 * @param a * @param b * @return */ public static String getFof(String a, String b) { int r = a.compareTo(b); if (r < 0) { return a + "\t" + b; }else { return b + "\t" + a; } } } 2, user类
package com.wenbronk.friend;import java.io.DataInput;import java.io.DataOutput;import java.io.IOException;import org.apache.hadoop.io.WritableComparable;public class User implements WritableComparable{ private String uname; private int friedsCount; public String getUname() { return uname; } public void setUname(String uname) { this.uname = uname; } public int getFriedsCount() { return friedsCount; } public void setFriedsCount(int friedsCount) { this.friedsCount = friedsCount; } public User() { super(); } public User(String uname, int friedsCount) { super(); this.uname = uname; this.friedsCount = friedsCount; } @Override public void readFields(DataInput arg0) throws IOException { this.uname = arg0.readUTF(); this.friedsCount = arg0.readInt(); } @Override public void write(DataOutput arg0) throws IOException { arg0.writeUTF(uname); arg0.writeInt(friedsCount); } @Override public int compareTo(User o) { int result = this.uname.compareTo(o.getUname()); if (result == 0) { return Integer.compare(this.friedsCount, o.getFriedsCount()); } return result; } }
3, sort
package com.wenbronk.friend;import org.apache.hadoop.io.WritableComparable;import org.apache.hadoop.io.WritableComparator;/** * 排序 * @author root * */public class FofSort extends WritableComparator { public FofSort() { super(User.class, true); } @Override public int compare(WritableComparable a, WritableComparable b) { User user1 = (User) a; User user2 = (User) b; int compareTo = user1.getUname().compareTo(user2.getUname()); if (compareTo == 0) { compareTo = Integer.compare(user1.getFriedsCount(), user2.getFriedsCount()); } return compareTo; } }
4, group
package com.wenbronk.friend;import org.apache.hadoop.io.WritableComparable;import org.apache.hadoop.io.WritableComparator;/** * 自定义分组 * @author root * */public class FofGroup extends WritableComparator { public FofGroup() { super(User.class, true); } @Override public int compare(WritableComparable a, WritableComparable b) { User u1 = (User) a; User u2 = (User) b; return u1.getUname().compareTo(u2.getUname()); } } 5, job
package com.wenbronk.friend;import java.io.IOException;import org.apache.commons.lang.StringUtils;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.FileSystem;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.input.KeyValueTextInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;/** * 1个mapreduce找到所有的fof关系 第二个mapreduce执行排序 * * @author root */public class RunJob { public static void main(String[] args) throws IOException { Configuration configuration = new Configuration();// configuration.set("mapred.jar", "C:/Users/wenbr/Desktop/fof.jar"); // 本地运行 configuration.set("fs.default", "hdfs://wenbronk.hdfs.com:8020 "); configuration.set("yarn.resourcemanager", "hdfs://192.168.208.106"); if (runFindFof(configuration)) { // 根据foffind进行排序 run2(configuration); } } /** * 找到所有的fof关系 * @throws IOException */ private static boolean runFindFof(Configuration conf) throws IOException { try { FileSystem fs = FileSystem.get(conf); Job job = Job.getInstance(conf); job.setJobName("friend"); job.setJarByClass(RunJob.class); job.setMapperClass(FofMapper.class); job.setReducerClass(FofReduce.class); job.setMapOutputKeyClass(Fof.class); job.setMapOutputValueClass(IntWritable.class); // job.setJar("C:/Users/wenbr/Desktop/friend.jar"); job.setInputFormatClass(KeyValueTextInputFormat.class);// FileInputFormat.addInputPath(job, new Path("/usr/friend.txt")); FileInputFormat.addInputPath(job, new Path("E:\\sxt\\1-MapReduce\\data\\friend.txt")); Path path = new Path("/root/usr/fof/f1"); if (fs.exists(path)) { fs.delete(path, true); } FileOutputFormat.setOutputPath(job, path); return job.waitForCompletion(true); }catch(Exception e) { e.printStackTrace(); } return false; } static class FofMapper extends Mapper { @Override protected void map(Text key, Text value, Mapper .Context context) throws IOException, InterruptedException { // super.map(key, value, context); String user = key.toString(); String[] frieds = StringUtils.split(value.toString(), '\t'); for (int i = 0; i < frieds.length; i++) { String f1 = frieds[i]; // 去掉是直接好友的, 按组输出, 如果组中有value=0 的, 整组数据舍弃 context.write(new Fof(user, f1), new IntWritable(0)); for (int j = i + 1; j < frieds.length; j++) { String f2 = frieds[j]; Fof fof = new Fof(f1, f2); context.write(fof, new IntWritable(1)); } } } } static class FofReduce extends Reducer { @Override protected void reduce(Fof arg0, Iterable arg1, Reducer .Context arg2) throws IOException, InterruptedException { boolean flag = false; int sum = 0; for (IntWritable count : arg1) { // 值有0的, 整组数据舍弃 if (count.get() == 0) { flag = true; break; } else { sum += count.get(); } } if (!flag) { arg2.write(arg0, new IntWritable(sum)); } } } /** * 向用户推荐好友 * @param config */ public static void run2(Configuration config) { try { FileSystem fileSystem = FileSystem.get(config); Job job = Job.getInstance(config); job.setJobName("fof2"); job.setMapperClass(SortMapper.class); job.setReducerClass(SortReduce.class); job.setSortComparatorClass(FofSort.class); job.setGroupingComparatorClass(FofGroup.class); job.setMapOutputKeyClass(User.class); job.setMapOutputValueClass(User.class); job.setInputFormatClass(KeyValueTextInputFormat.class); // 设置MR执行的输入文件 FileInputFormat.addInputPath(job, new Path("/usr/output/f1")); // 设置输出文件, 文件不可存在 Path path = new Path("/root/usr/fof/f2"); if (fileSystem.exists(path)) { fileSystem.delete(path, true); } FileOutputFormat.setOutputPath(job, path); boolean f = job.waitForCompletion(true); if (f) { System.out.println("job, 成功执行"); } }catch (Exception e) { e.printStackTrace(); } } static class SortMapper extends Mapper { @Override protected void map(Text key, Text value, Mapper .Context context) throws IOException, InterruptedException { String[] args = StringUtils.split(value.toString(), '\t'); String other = args[0]; int friendsCount = Integer.parseInt(args[1]); // 输出两次, 同时给fof两个用户推荐好友 context.write(new User(key.toString(), friendsCount), new User(other, friendsCount)); context.write(new User(other, friendsCount), new User(key.toString(), friendsCount)); } } static class SortReduce extends Reducer { @Override protected void reduce(User arg0, Iterable arg1, Reducer .Context arg2) throws IOException, InterruptedException { String uname = arg0.getUname(); StringBuilder stringBuilder = new StringBuilder(); for (User user : arg1) { stringBuilder.append(user.getUname() + ": " + user.getFriedsCount()); stringBuilder.append(", "); } arg2.write(new Text(uname), new Text(stringBuilder.toString())); } }}
初始文档
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