Could not locate executable null\bin\winutils.exe in the Hadoop binaries

在本地调试hadoop和spark程序时一直报一个错误Could not locate executable null\bin\winutils.exe in the Hadoop binaries：，看起来像是HADOOP_HOME没有配置，但我明明配置了啊，检查了好几遍也没发现问题，跟进取可以看到在hadoop.util.Shell中有一个checkHadoopHome的方法，

private static String checkHadoopHome() {

// first check the Dflag hadoop.home.dir with JVM scope
String home = System.getProperty("hadoop.home.dir");

// fall back to the system/user-global env variable
if (home == null) {
home = System.getenv("HADOOP_HOME");
}

try {
// couldn't find either setting for hadoop's home directory
if (home == null) {
throw new IOException("HADOOP_HOME or hadoop.home.dir are not set.");
}

if (home.startsWith("\"") && home.endsWith("\"")) {
home = home.substring(1, home.length()-1);
}

// check that the home setting is actually a directory that exists
File homedir = new File(home);
if (!homedir.isAbsolute() || !homedir.exists() || !homedir.isDirectory()) {
throw new IOException("Hadoop home directory " + homedir
+ " does not exist, is not a directory, or is not an absolute path.");
}

home = homedir.getCanonicalPath();

} catch (IOException ioe) {
if (LOG.isDebugEnabled()) {
LOG.debug("Failed to detect a valid hadoop home directory", ioe);
}
home = null;
}

return home;
}

可以看到它首先是从hadoop.home.dir这个系统变量中获取，无奈只好在运行时通过System.setProperty("hadoop.home.dir", "E:/asWorkSpace/hadoop")来进行手动配置，后来实在想不明白，就一步步调试了一下，发现是在if (!homedir.isAbsolute()|| !homedir.exists() || !homedir.isDirectory())这一步出了问题，”E:/asWorkSpace/hadoop“即不是绝对路径，也不存在，这就搞不懂了，没办法只好将HADOOP_HOME配置成“E://asWorkSpace//hadoop”的形式，问题解决了，不用每次手动设置了，但是为啥HADOOP_HOME的路径设置和JAVA_HOME的格式不一样，我还是没搞懂，不知道还有没有人碰到过这个奇怪的问题。