关于java.io.IOException: HADOOP_HOME or hadoop.home.dir are not set.的问题

报错如下：

300 [main] DEBUG org.apache.hadoop.util.Shell  - Failed to detect a valid hadoop home directory
java.io.IOException: HADOOP_HOME or hadoop.home.dir are not set

解决办法一：

根据 http://blog.csdn.net/baidu_19473529/article/details/54693523 配置hadoop_home变量

下载winutils地址https://github.com/srccodes/hadoop-common-2.2.0-bin下载解压

重新打开Eclipse，运行程序，可以解决内网的Hadoop连接问题。（亲测试通过）

解决办法二：

在java程序中加入

System.setProperty("hadoop.home.dir", "/usr/local/hadoop-2.6.0");

依然报错（未亲测试）

解决办法三：（不是同一问题？）

根据该提示：

依然报错

--------------------------------5.19.早晨------------------------------------------

今天早上再次执行该程序，将上传到HDFS部分的代码给注释掉后发现日志报错信息如下：

132 [main] DEBUG org.apache.hadoop.util.NativeCodeLoader  - Trying to load the custom-built native-hadoop library...
134 [main] DEBUG org.apache.hadoop.util.NativeCodeLoader  - Failed to load native-hadoop with error: java.lang.UnsatisfiedLinkError: no hadoop in java.library.path

1）check Hadoop library：

root@Ubuntu-1:/usr/local/hadoop-2.6.0/lib/native# file libhadoop.so.1.0.

It's 64-bite library

2）Try adding the HADOOP_OPTS environment variable:

root@Ubuntu-1:~# vi /etc/profile                            //environment variable

export HADOOP_OPTS="-Djava.library.path=${HADOOP_HOME}/lib/native/"

It doesn't work, and reports the same error.

3）Try adding the HADOOP_OPTS and HADOOP_COMMON_LIB_NATIVE_DIR environment variable:

export HADOOP_COMMON_LIB_NATIVE_DIR=${HADOOP_HOME}/lib/native

export HADOOP_OPTS="-Djava.library.path=${HADOOP_HOME}/lib/"

It still doesn't work, and reports the same error.

4）Adding the Hadoop library into LD_LIBRARY_PATH

root@Ubuntu-1:~# vi .bashrc 
export LD_LIBRARY_PATH=/usr/local/hadoop/lib/native/:$LD_LIBRARY_PATH

It doesn't work, and reports the same error.

5）append word native to HADOOP_OPTS like this

export HADOOP_OPTS="$HADOOP_OPTS -Djava.library.path=$HADOOP_HOME/lib/native"

It doesn't work, and reports the same error.

-----------------------------------5.20早晨-------------------------

win下依旧无法使用java代码上传文件到HDFS

----------------------------------5.24------------

copy了一份hadoop-2.6.0文件到本机，更改bin目录和path ，显示无效的path，遂更改回去

---------------------2017.5.26-------------------

今天早上开机 试了一下 发现它已经好了  其实上述的设置已经可以解决大部分遇到这类问题的人群