2
在Window下启动Hadoop-0.21.0版本时，会出现下面这样的错误提示：
- java.lang.NoClassDefFoundError: org/apache/hadoop/util/PlatformName
- Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.util.PlatformName
-
- at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
- at java.security.AccessController.doPrivileged(Native Method)
- at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
- at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
- at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
- at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
- Could not find the main class: org.apache.hadoop.util.PlatformName. Program will exit.
经过不断的查找原因和尝试，终于有了解决这个错误的办法，只需要将${HADOOP_HOME}/bin/hadoop-config.sh文件中的第190行的一下的内容
JAVA_PLATFORM=`CLASSPATH=${CLASSPATH}
${JAVA} -Xmx32m ${HADOOP_JAVA_PLATFORM_OPTS} org.apache.hadoop.util.PlatformName
| sed -e "s/ /_/g"`
改成
JAVA_PLATFORM=`CLASSPATH=${CLASSPATH}
${JAVA} -Xmx32m -classpath ${HADOOP_COMMON_HOME}/hadoop-common-0.21.0.jar
org.apache.hadoop.util.PlatformName | sed -e "s/ /_/g"`
