版本号：
CDH5.0.0 （hdfs:2.3。mapreduce：2.3，yarn：2.3）
hadoop多文件格式输入，一般能够使用MultipleInputs类指定不同的输入文件路径以及输入文件格式。
比方如今有例如以下的需求：
现有两份数据：
phone：
123,good number 124,common number 125,bad numberuser：
zhangsan,123 lisi,124 wangwu,125
如今须要把user和phone依照phone number连接起来，得到以下的结果：
zhangsan,123,good number lisi,124,common number wangwu,125,bad number那么就能够使用MultipleInputs来操作，这里把user和phone上传到hdfs文件夹中，各自是/multiple/user/user , /multiple/phone/phone。
设计的MultipleDriver例如以下：
package multiple.input;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.MultipleInputs;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
//import org.slf4j.Logger;
//import org.slf4j.LoggerFactory;
/**
* input1(/multiple/user/user):
* username,user_phone
*
* input2(/multiple/phone/phone):
* user_phone,description
*
* output: username,user_phone,description
*
* @author fansy
*
*/
public class MultipleDriver extends Configured implements Tool{
// private Logger log = LoggerFactory.getLogger(MultipleDriver.class);
private String input1=null;
private String input2=null;
private String output=null;
private String delimiter=null;
public static void main(String[] args) throws Exception {
Configuration conf=new Configuration();
// conf.set("fs.defaultFS", "hdfs://node33:8020");
// conf.set("mapreduce.framework.name", "yarn");
// conf.set("yarn.resourcemanager.address", "node33:8032");
ToolRunner.run(conf, new MultipleDriver(), args);
}
@Override
public int run(String[] arg0) throws Exception {
configureArgs(arg0);
checkArgs();
Configuration conf= getConf();
conf.set("delimiter", delimiter);
@SuppressWarnings("deprecation")
Job job = new Job(conf, "merge user and phone information ");
job.setJarByClass(MultipleDriver.class);
job.setReducerClass(MultipleReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(FlagStringDataType.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(NullWritable.class);
job.setNumReduceTasks(1);
MultipleInputs.addInputPath(job, new Path(input1), TextInputFormat.class, Multiple1Mapper.class);
MultipleInputs.addInputPath(job, new Path(input2), TextInputFormat.class, Multiple2Mapper.class);
FileOutputFormat.setOutputPath(job, new Path(output));
int res = job.waitForCompletion(true) ? 0 : 1;
return res;
}
/**
* check the args
*/
private void checkArgs() {
if(input1==null||"".equals(input1)){
System.out.println("no user input...");
printUsage();
System.exit(-1);
}
if(input2==null||"".equals(input2)){
System.out.println("no phone input...");
printUsage();
System.exit(-1);
}
if(output==null||"".equals(output)){
System.out.println("no output...");
printUsage();
System.exit(-1);
}
if(delimiter==null||"".equals(delimiter)){
System.out.println("no delimiter...");
printUsage();
System.exit(-1);
}
}
/**
* configuration the args
* @param args
*/
private void configureArgs(String[] args) {
for(int i=0;i<args.length;i++){
if("-i1".equals(args[i])){
input1=args[++i];
}
if("-i2".equals(args[i])){
input2=args[++i];
}
if("-o".equals(args[i])){
output=args[++i];
}
if("-delimiter".equals(args[i])){
delimiter=args[++i];
}
}
}
public static void printUsage(){
System.err.println("Usage:");
System.err.println("-i1 input user data path.");
System.err.println("-i2 input phone data path.");
System.err.println("-o output output data path.");
System.err.println("-delimiter data delimiter , default is comma .");
}
}
这里指定两个mapper和一个reducer，两个mapper分别相应处理user和phone的数据，分别例如以下：
mapper1（处理user数据）：
package multiple.input;
import java.io.IOException;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* input :
* username,phone
*
* output:
* <key,value> --> <[phone],[0,username]>
* @author fansy
*
*/
public class Multiple1Mapper extends Mapper<LongWritable,Text,Text,FlagStringDataType>{
private Logger log = LoggerFactory.getLogger(Multiple1Mapper.class);
private String delimiter=null; // default is comma
@Override
public void setup(Context cxt){
delimiter= cxt.getConfiguration().get("delimiter", ",");
log.info("This is the begin of Multiple1Mapper");
}
@Override
public void map(LongWritable key,Text value,Context cxt) throws IOException,InterruptedException{
String info= new String(value.getBytes(),"UTF-8");
String[] values = info.split(delimiter);
if(values.length!=2){
return;
}
log.info("key-->"+values[1]+"=========value-->"+"[0,"+values[0]+"]");
cxt.write(new Text(values[1]), new FlagStringDataType(0,values[0]));
}
}
mapper2（处理phone数据）：
package multiple.input;
import java.io.IOException;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* input :
* phone,description
*
* output:
* <key,value> --> <[phone],[1,description]>
* @author fansy
*
*/
public class Multiple2Mapper extends Mapper<LongWritable,Text,Text,FlagStringDataType>{
private Logger log = LoggerFactory.getLogger(Multiple2Mapper.class);
private String delimiter=null; // default is comma
@Override
public void setup(Context cxt){
delimiter= cxt.getConfiguration().get("delimiter", ",");
log.info("This is the begin of Multiple2Mapper");
}
@Override
public void map(LongWritable key,Text value,Context cxt) throws IOException,InterruptedException{
String[] values= value.toString().split(delimiter);
if(values.length!=2){
return;
}
log.info("key-->"+values[0]+"=========value-->"+"[1,"+values[1]+"]");
cxt.write(new Text(values[0]), new FlagStringDataType(1,values[1]));
}
}
这里的FlagStringDataType是自己定义的：package multiple.input;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import org.apache.hadoop.io.WritableComparable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.primitives.Ints;
public class FlagStringDataType implements WritableComparable<FlagStringDataType> {
private Logger log = LoggerFactory.getLogger(FlagStringDataType.class);
private String value;
private int flag;
public FlagStringDataType() {
}
public FlagStringDataType(int flag,String value) {
this.value = value;
this.flag=flag;
}
public String get() {
return value;
}
public void set(String value) {
this.value = value;
}
@Override
public boolean equals(Object other) {
return other != null && getClass().equals(other.getClass())
&& ((FlagStringDataType) other).get() == value
&&((FlagStringDataType) other).getFlag()==flag;
}
@Override
public int hashCode() {
return Ints.hashCode(flag)+value.hashCode();
}
@Override
public int compareTo(FlagStringDataType other) {
if (flag >= other.flag) {
if (flag > other.flag) {
return 1;
}
} else {
return -1;
}
return value.compareTo(other.value);
}
@Override
public void write(DataOutput out) throws IOException {
log.info("in write()::"+"flag:"+flag+",vlaue:"+value);
out.writeInt(flag);
out.writeUTF(value);
}
@Override
public void readFields(DataInput in) throws IOException {
log.info("in read()::"+"flag:"+flag+",vlaue:"+value);
flag=in.readInt();
value = in.readUTF();
log.info("in read()::"+"flag:"+flag+",vlaue:"+value);
}
public int getFlag() {
return flag;
}
public void setFlag(int flag) {
this.flag = flag;
}
public String toString(){
return flag+":"+value;
}
}
这个自己定义类，使用一个flag来指定是哪个数据。而value则相应是其值。
这样做的优点是在reduce端能够依据flag的值来推断其输出位置。这样的设计方式能够对多种输入的整合有非常大帮助，在mahout中也能够看到这样的设计。
reducer（汇总输出数据）：
package multiple.input;
import java.io.IOException;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MultipleReducer extends Reducer<Text,FlagStringDataType,Text,NullWritable>{
private Logger log = LoggerFactory.getLogger(MultipleReducer.class);
private String delimiter=null; // default is comma
@Override
public void setup(Context cxt){
delimiter= cxt.getConfiguration().get("delimiter", ",");
}
@Override
public void reduce(Text key, Iterable<FlagStringDataType> values,Context cxt) throws IOException,InterruptedException{
log.info("================");
log.info(" =======");
log.info(" ==");
String[] value= new String[3];
value[2]=key.toString();
for(FlagStringDataType v:values){
int index= v.getFlag();
log.info("index:"+index+"-->value:"+v.get());
value[index]= v.get();
}
log.info(" ==");
log.info(" =======");
log.info("================");
cxt.write(new Text(value[2]+delimiter+value[0]+delimiter+value[1]),NullWritable.get());
}
}
这样设计的优点是，能够针对不同的输入数据採取不同的逻辑处理。并且不同的输入数据能够是序列文件的格式。
以下介绍一种方式和上面的比。略有不足。可是能够借鉴。
首先是Driver：
package multiple.input;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
//import org.slf4j.Logger;
//import org.slf4j.LoggerFactory;
/**
* input1(/multiple/user/user):
* username,user_phone
*
* input2(/multiple/phone/phone):
* user_phone,description
*
* output: username,user_phone,description
*
* @author fansy
*
*/
public class MultipleDriver2 extends Configured implements Tool{
// private Logger log = LoggerFactory.getLogger(MultipleDriver.class);
private String input1=null;
private String input2=null;
private String output=null;
private String delimiter=null;
public static void main(String[] args) throws Exception {
Configuration conf=new Configuration();
// conf.set("fs.defaultFS", "hdfs://node33:8020");
// conf.set("mapreduce.framework.name", "yarn");
// conf.set("yarn.resourcemanager.address", "node33:8032");
ToolRunner.run(conf, new MultipleDriver2(), args);
}
@Override
public int run(String[] arg0) throws Exception {
configureArgs(arg0);
checkArgs();
Configuration conf= getConf();
conf.set("delimiter", delimiter);
@SuppressWarnings("deprecation")
Job job = new Job(conf, "merge user and phone information ");
job.setJarByClass(MultipleDriver2.class);
job.setMapperClass(MultipleMapper.class);
job.setReducerClass(MultipleReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(FlagStringDataType.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(NullWritable.class);
job.setNumReduceTasks(1);
FileInputFormat.addInputPath(job, new Path(input1));
FileInputFormat.addInputPath(job, new Path(input2));
FileOutputFormat.setOutputPath(job, new Path(output));
int res = job.waitForCompletion(true) ? 0 : 1;
return res;
}
/**
* check the args
*/
private void checkArgs() {
if(input1==null||"".equals(input1)){
System.out.println("no user input...");
printUsage();
System.exit(-1);
}
if(input2==null||"".equals(input2)){
System.out.println("no phone input...");
printUsage();
System.exit(-1);
}
if(output==null||"".equals(output)){
System.out.println("no output...");
printUsage();
System.exit(-1);
}
if(delimiter==null||"".equals(delimiter)){
System.out.println("no delimiter...");
printUsage();
System.exit(-1);
}
}
/**
* configuration the args
* @param args
*/
private void configureArgs(String[] args) {
for(int i=0;i<args.length;i++){
if("-i1".equals(args[i])){
input1=args[++i];
}
if("-i2".equals(args[i])){
input2=args[++i];
}
if("-o".equals(args[i])){
output=args[++i];
}
if("-delimiter".equals(args[i])){
delimiter=args[++i];
}
}
}
public static void printUsage(){
System.err.println("Usage:");
System.err.println("-i1 input user data path.");
System.err.println("-i2 input phone data path.");
System.err.println("-o output output data path.");
System.err.println("-delimiter data delimiter , default is comma .");
}
}
这里加入路径直接使用FileInputFormat加入输入路径，这样的话，针对不同的输入数据的不同业务逻辑能够在mapper中先推断眼下正在处理的是那个数据。然后依据其路径来进行相应的业务逻辑处理：
package multiple.input;
import java.io.IOException;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
/**
* input1 :
* username,phone
*
* input2
* phone,description
*
* output:
* <key,value> --> <[phone],[0,username]>
* <key,value> --> <[phone],[1,description]>
* @author fansy
*
*/
public class MultipleMapper extends Mapper<LongWritable,Text,Text,FlagStringDataType>{
private String delimiter=null; // default is comma
private boolean flag=false;
@Override
public void setup(Context cxt){
delimiter= cxt.getConfiguration().get("delimiter", ",");
InputSplit input=cxt.getInputSplit();
String filename=((FileSplit) input).getPath().getParent().getName();
if("user".equals(filename)){
flag=true;
}
}
@Override
public void map(LongWritable key,Text value,Context cxt) throws IOException,InterruptedException{
String[] values= value.toString().split(delimiter);
if(values.length!=2){
return;
}
if(flag){
cxt.write(new Text(values[1]), new FlagStringDataType(0,values[0]));
}else{
cxt.write(new Text(values[0]), new FlagStringDataType(1,values[1]));
}
}
}
整体来说。这样的处理方式事实上是不如第一种的，在每一个map函数中都须要进行推断。比第一种多了非常多操作；同一时候。针对不同的序列文件，这样的方式处理不了（Key、value的类型不一样的情况下）。
所以针对多文件格式的输入，不妨使用第一种方式。
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