javaAPI操作hdfs文件系统环境准备

解决javaAPI操作hdfs文件系统问题

解决正常运行hadoop hdfs javaAPI

java.lang.NullPointerException

at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)

at org.apache.hadoop.util.Shell.runCommand(Shell.java:482)

at org.apache.hadoop.util.Shell.run(Shell.java:455)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:808)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:791)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:659)
at org.apache.hadoop.fs.FilterFileSystem.setPermission(FilterFileSystem.java:490)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:462)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:428)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:908)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:889)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:786)
at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:365)
at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:338)
at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:289)
at org.apache.hadoop.fs.LocalFileSystem.copyFromLocalFile(LocalFileSystem.java:82)
at org.apache.hadoop.fs.FileSystem.copyFromLocalFile(FileSystem.java:1838)
at cn.yzx.bigdata.hdfs.HdfsClientDemo.testUpload(HdfsClientDemo.java:23)
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:497)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

1.材料

hadoop-2.6.5-centos-6.7.tar.gz

无jar版windows平台hadoop-2.6.1.zip

2.new Java  Project

3.hdfsjar

解压hadoop-2.6.5-centos-6.7.tar.gz  
hadoop-2.6.5\share\hadoop\hdfs  下把hadoop-hdfs-2.6.5.jar 和当前目录lib下所有都导入hdfsjar

hadoop-2.6.5\share\hadoop\common 下把hadoop-common-2.6.5.jar 和当前目录lib下所有都导入hdfsjar

4. 代码

5.跑代码发现问题

6配置环境变量

7重启eclipse再跑代码

8.发现并没有成功

1.执行成功,但没有上传到hadoop hdfs文件下

解决方案:

配置Hadoop的文件系统地址

添加代码

2.权限问题:用户名不能是Administrator

解决方案:
设置hadoop用户名



设置hadoop名称

点 run  Configuration



以上问题解决,就可以正常运行hadoop
hdfs javaAPI了!!!