編譯hadoop2.2版本步驟：http://blog.csdn.net/hebutscs/article/details/29359635
wordcount程序：http://www.cnblogs.com/minkaihui/p/4074035.html
maven構建本地倉庫命令：mvn install:install-file -Dfile=sinaWeibo.jar -DgroupId=com.test.tanyy -DartifactId=qqLoginSdk4J -Dversion=1.0 -Dpackaging=jar
log4j數據寫入到數據庫：http://demojava.iteye.com/blog/1067627
1、tomcat啟動時，出現下面錯誤，然后tomcat不能正常關閉：
九月 06, 2014 9:53:43 上午 org.apache.catalina.core.StandardServer await
警告: StandardServer.await: Invalid command 'SUTDOWN' received
2、運行頁面，偶爾出現
- Could not initialize class com.jx.classes.backend.container.ServiceProvider
- Could not instantiate bean class [com.jx.classes.backend.action.MainAction]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class com.jx.classes.backend.container.ServiceProvider
- Error creating bean with name 'com.jx.classes.backend.action.MainAction': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.jx.classes.backend.action.MainAction]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class com.jx.classes.backend.container.ServiceProvider
- Unable to instantiate Action, com.jx.classes.backend.action.MainAction, defined for 'main_index' in namespace '/'Error creating bean with name 'com.jx.classes.backend.action.MainAction': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.jx.classes.backend.action.MainAction]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class com.jx.classes.backend.container.ServiceProvider
3、Caused by: java.lang.ClassNotFoundException: org.springframework.aop.support.AopUtils
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 32 more
在spring項目中找到modules 加入spring-aop.jar即可
4、使用maven編譯hadoop2.2出錯：
Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:2.2.0:protoc (compile-protoc) on project hadoop-common: org.apache.maven.plugin.MojoExecutionException: protoc version is 'libprotoc 2.4.1', expected version is '2.5.0' -> [Help 1]
5、Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:2.2.0:protoc (compile-protoc) on project hadoop-common: org.apache.maven.plugin.MojoExecutionException: protoc failure
使用spring mvc和maven 的時候報錯：java.lang.ClassNotFoundException: org.springframework.web.util.Log4jConfigListener
解決辦法：ctrl+Enter 報錯項目->Deployment Assembly->Add->Java buid path entries->Next->Maven Dependencies