小编use*_*477的帖子

我正在尝试运行Giraph附带的SimpleInDegreeCountComputation示例.我的方法如下:

SimpleInDegreeCountComputation.java:

    public class SimpleInDegreeCountComputation extends BasicComputation
              <LongWritable, LongWritable, DoubleWritable, DoubleWritable> {
    .......

然后我尝试运行它:

    hadoop jar /path-to-giraph-folder/giraph-examples/target/giraph-examples-1.1.0- 
    SNAPSHOT-for-hadoop-1.2.1-jar-with-dependencies.jar 
    org.apache.giraph.GiraphRunner  
    org.apache.giraph.examples.SimpleInDegreeCountComputation 
    -vif org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexInputFormat 
    -vip /path-to-input-file 
    -vof org.apache.giraph.io.formats.IdWithValueTextOutputFormat 
    -op /path-to-output-file -w 1 

结果如下:

    14/05/18 18:58:40 INFO utils.ConfigurationUtils: No edge input format specified. 
    Ensure your InputFormat does not require one.
    14/05/18 18:58:40 INFO utils.ConfigurationUtils: No edge output format specified.  
    Ensure your OutputFormat does not require one.
    Exception in thread "main" java.lang.IllegalArgumentException: checkClassTypes: vertex  
    value types not assignable, computation - class org.apache.hadoop.io.LongWritable,   
    VertexInputFormat - …