Java 从mapper将2个矩阵作为键和值发出时的问题

我得到一个输入文件作为参数，并将其复制到HDFS中进行一些初始计算
这个文件将作为我的映射器的输入
在一些矩阵计算之后，我需要向Reducer发送两个双数组。 但当我这么做的时候，它表明：

13/10/26 09:13:49 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
13/10/26 09:13:49 WARN conf.Configuration: session.id is deprecated. Instead, use dfs.metrics.session-id
13/10/26 09:13:49 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
13/10/26 09:13:49 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
13/10/26 09:13:49 WARN mapred.JobClient: No job jar file set.  User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
13/10/26 09:13:49 INFO input.FileInputFormat: Total input paths to process : 1
13/10/26 09:13:50 INFO mapred.LocalJobRunner: OutputCommitter set in config null
13/10/26 09:13:50 INFO mapred.JobClient: Running job: job_local1799392614_0001
13/10/26 09:13:50 INFO mapred.LocalJobRunner: OutputCommitter is org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter
13/10/26 09:13:50 INFO mapred.LocalJobRunner: Waiting for map tasks
13/10/26 09:13:50 INFO mapred.LocalJobRunner: Starting task: attempt_local1799392614_0001_m_000000_0
13/10/26 09:13:50 WARN mapreduce.Counters: Group org.apache.hadoop.mapred.Task$Counter is deprecated. Use org.apache.hadoop.mapreduce.TaskCounter instead
13/10/26 09:13:50 INFO util.ProcessTree: setsid exited with exit code 0
13/10/26 09:13:50 INFO mapred.Task:  Using ResourceCalculatorPlugin : org.apache.hadoop.util.LinuxResourceCalculatorPlugin@40cdc794
13/10/26 09:13:50 INFO mapred.MapTask: Map output collector class = org.apache.hadoop.mapred.MapTask$MapOutputBuffer
13/10/26 09:13:50 INFO mapred.MapTask: io.sort.mb = 100
13/10/26 09:13:50 INFO mapred.MapTask: data buffer = 79691776/99614720
13/10/26 09:13:50 INFO mapred.MapTask: record buffer = 262144/327680
13/10/26 09:13:50 INFO mapred.LocalJobRunner: Map task executor complete.
13/10/26 09:13:50 WARN mapred.LocalJobRunner: job_local1799392614_0001
java.lang.Exception: java.lang.ClassCastException: class edu.Driver$DoubleArrayWritable
    at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:404)
Caused by: java.lang.ClassCastException: class edu.Driver$DoubleArrayWritable
    at java.lang.Class.asSubclass(Class.java:3037)
    at org.apache.hadoop.mapred.JobConf.getOutputKeyComparator(JobConf.java:819)
    at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.init(MapTask.java:836)
    at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:376)
    at org.apache.hadoop.mapred.MapTask.access$100(MapTask.java:85)
    at org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:584)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:656)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:330)
    at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:266)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
13/10/26 09:13:51 INFO mapred.JobClient:  map 0% reduce 0%
13/10/26 09:13:51 INFO mapred.JobClient: Job complete: job_local1799392614_0001
13/10/26 09:13:51 INFO mapred.JobClient: Counters: 0

我的2d阵列是：

public static class DoubleArrayWritable extends TwoDArrayWritable {
    public DoubleArrayWritable() {
        super(DoubleWritable.class);
    }
}

我的Mapper类：

public class Mapper extends Mapper<Object, Text, DoubleArrayWritable, DoubleArrayWritable> {

public void map(Object key, Text value, Context context)
        throws IOException, InterruptedException {

            DoubleArrayWritable EArray = new DoubleArrayWritable();
            DoubleWritable[][] Edata = new DoubleWritable[Erow][Ecol];
            for (int k = 0; k < Erow; k++) {
                for(int j=0;j< Ecol;j++){
                    Edata[k][j] = new DoubleWritable(E[k][j]);
                }
            }
            EArray.set(Edata);

            DoubleArrayWritable EDArray = new DoubleArrayWritable();
            DoubleWritable[][] EDdata = new DoubleWritable[EtransDerow][EtransDecol];
            for (int k1 = 0; k1 < EtransDerow; k1++) {
                for(int j1=0;j1< EtransDecol;j1++) {
                EDdata[k1][j1] = new DoubleWritable(ED[k1][j1]);
                }
            }
            EDArray.set(EDdata);

            context.write(EArray, EDArray);
}
}

制图员：

public class Mapper extends
        Mapper<Object, Text, IntWritable, DoubleArrayWritable> {

    public void map(Object key, Text value, Context context)
            throws IOException, InterruptedException {

        IntWritable clusterNumber = null;
        int count = 0;
        clusterNumber = new IntWritable(count); 
        context.write(clusterNumber, EArray);   
}
}

公共类映射器扩展
制图员{
公共无效映射（对象键、文本值、上下文）
抛出IOException、InterruptedException{
IntWritable clusterNumber=null；
整数计数=0；
clusterNumber=新的可写整数（计数）；
context.write（clusterNumber，array）；
}
}

减速器：

public class Reducer  extends
Reducer<IntWritable, DoubleArrayWritable, IntWritable, Text> {

    public void reduce(IntWritable key,
            Iterable<DoubleArrayWritable> values, Context context)
            throws IOException, InterruptedException {

            System.out.println("Entered into reducer. successfull");
    }
}

公共类缩减器扩展
减速器{
public void reduce（可写密钥，
Iterable值，上下文）
抛出IOException、InterruptedException{
System.out.println（“已成功输入减速机”）；
}
}

其次，我尝试发射两个双数组。通过更改配置，映射输出键/值和减速机输出键/值。

---

似乎

配置中有一些问题

看起来像是类加载器问题..我正在用3个单独的文件编写代码驱动程序、映射程序、还原程序。我还提到了驱动程序类中的类。那么，为什么会出现例外呢

job.setJarByClass(Driver.class);
job.setMapperClass(Mapper.class);

job.setReducerClass(Reducer.class);

job.setMapOutputKeyClass(IntWritable.class);
job.setMapOutputValueClass(DoubleArrayWritable.class);

job.setOutputKeyClass(TextOutputFormat.class);
job.setOutputValueClass(DoubleArrayWritable.class);

job.setInputFormatClass(TextInputFormat.class);
job.setOutputFormatClass(TextOutputFormat.class);

FileInputFormat.setInputPaths(job, "in/inputfile");
FileOutputFormat.setOutputPath(job,new Path(args[1]));

public class Mapper extends
        Mapper<Object, Text, IntWritable, DoubleArrayWritable> {

    public void map(Object key, Text value, Context context)
            throws IOException, InterruptedException {

        IntWritable clusterNumber = null;
        int count = 0;
        clusterNumber = new IntWritable(count); 
        context.write(clusterNumber, EArray);   
}
}

public class Reducer  extends
Reducer<IntWritable, DoubleArrayWritable, IntWritable, Text> {

    public void reduce(IntWritable key,
            Iterable<DoubleArrayWritable> values, Context context)
            throws IOException, InterruptedException {

            System.out.println("Entered into reducer. successfull");
    }
}