Я хочу запустить ниже программу, используя Hadoop-3.0.1. Я импортировал
Hadoop-client-API-3.0.1.jar, Hadoop-client-runtime-3.0.1.jar
и Hadoop-client-minicluster-3.0.1.jar
: < /p>
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class HDFSFileTest {
public static void main(String[]args) {
try {
String fileName="test.txt";
Configuration conf =new Configuration();
conf.set("fs.defaultFS","hdfs://localhost:9000");
conf.set("fs.hdfs.impl","org.apache.hadoop.hdfs.DistributedFileSystem");
FileSystem fs=FileSystem.get(conf);
if(fs.exists(new Path(fileName))) {
System.out.println("File exists!");
}
else {
System.out.println("File not exists!");
}
}
catch(Exception e){
e.printStackTrace();
}
}
}
< /code>
Я получаю исключение в Eclipse: < /p>
java.lang.ClassCastException:org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$GetFileInfoRequestProto cannot be cast to com.google.protobuf.Message
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:225)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy11.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:876)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359)
at com.sun.proxy.$Proxy12.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1619)
at org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1494)
at org.apache.hadoop.hdfs.DistributedFileSystem$29.doCall(DistributedFileSystem.java:1491)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1506)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1668)
Подробнее здесь: https://stackoverflow.com/questions/498 ... uf-message
