Я новичок в Hadoop.
Моя версия hadoop - 2.8.1, и я использую Eclipse Oxygen 3a.
Я пытаюсь протестировать Hadoop HDFS Library в Java. Возможно ли , могу ли я напрямую подключиться к HDFS с помощью библиотеки FileSystem на Java Eclipse ? А именно, я хочу сделать тестирование библиотеки hdfs в Java Eclipse , а не в cmd.
Вот мой исходный код. Этот источник работает в распределенной среде hadoop. Однако, когда я тестирую в одиночном режиме, он не работает.
package us.qi.hdfs;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
public class HDFS_Test{
public static void main(String args[]) throws Exception {
String uri = "hdfs://mycluster:9000";
Configuration conf = new Configuration();
conf.set("fs.defaultFS", uri);
conf.addResource(new Path("/home/hadoop/hadoop-2.8.1/etc/hadoop/core-site.xml"));
conf.addResource(new Path("/home/hadoop/hadoop-2.8.1/etc/hadoop/hdfs-site.xml"));
FileSystem fs = FileSystem.get(URI.create(uri), conf);
Path[] paths = new Path[args.length];
for (int i = 0;i < paths.length; i++) {
paths[i] = new Path(args[i]);
}
FileStatus[] status = fs.listStatus(paths);
Path[] listPaths = FileUtil.stat2Paths(status);
for (Path p : listPaths) {
System.out.println(p);
}
}
}
Кроме того, вызов объекта конфигурации в Java приводит к следующей ошибке:
log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: /datanode-metrics.log (Permission denied)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:133)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
at org.apache.log4j.RollingFileAppender.setFile(RollingFileAppender.java:207)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:307)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:172)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:104)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:842)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768)
at org.apache.log4j.PropertyConfigurator.parseCatsAndRenderers(PropertyConfigurator.java:672)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:516)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.apache.log4j.Logger.getLogger(Logger.java:104)
at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:262)
at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:108)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(LogFactoryImpl.java:1025)
at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:844)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:541)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:292)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:269)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:657)
at org.apache.hadoop.conf.Configuration.<clinit>(Configuration.java:185)
at us.qi.hdfs.HDFS_Test.main(HDFS_Test.java:16)
log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: /namenode-metrics.log (Permission denied)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:133)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
at org.apache.log4j.RollingFileAppender.setFile(RollingFileAppender.java:207)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:307)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:172)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:104)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:842)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768)
at org.apache.log4j.PropertyConfigurator.parseCatsAndRenderers(PropertyConfigurator.java:672)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:516)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.apache.log4j.Logger.getLogger(Logger.java:104)
at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:262)
at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:108)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(LogFactoryImpl.java:1025)
at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:844)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:541)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:292)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:269)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:657)
at org.apache.hadoop.conf.Configuration.<clinit>(Configuration.java:185)
at us.qi.hdfs.HDFS_Test.main(HDFS_Test.java:16)
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/collections/map/UnmodifiableMap
at org.apache.hadoop.conf.Configuration$DeprecationContext.<init>(Configuration.java:416)
at org.apache.hadoop.conf.Configuration.<clinit>(Configuration.java:456)
at us.qi.hdfs.HDFS_Test.main(HDFS_Test.java:16)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.map.UnmodifiableMap
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 3 more
Если кто-то знает решение, пожалуйста, помогите мне.
Спасибо.