该文章用于整理开发中遇到的一些错误，及解决方法，不断整理更新。

1. 缺包异常

异常1：
java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
at org.springframework.web.context.ContextLoader.<clinit>(ContextLoader.java:146)
at org.springframework.web.context.ContextLoaderListener.createContextLoader(ContextLoaderListener.java:53)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:44)
需要加上:commons-logging.jar，log4j-1.2.11.jar
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异常2：
org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from class path resource [text.xml]; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
Caused by: java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException
at java.lang.Class.forName0(Native Method)
需要加上:aspectjweaver.jar
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异常3：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘logBean’ defined in class path resource [spring.xml]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available. Add CGLIB to the class path or specify proxy interfaces.
Caused by: org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available. Add CGLIB to the class path or specify proxy interfaces.
需要加上:cglib-2.1.3.jar
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异常4：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘logBean’ defined in class path resource of ServletContext: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: javax/transaction/TransactionManager
java.lang.NoClassDefFoundError: javax/transaction/TransactionManager
需要加上:jta.jar
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异常6:
java.lang.NoClassDefFoundError: org/dom4j/Attribute
需要加上:dom4j.jar
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异常7:
java.lang.NoClassDefFoundError: net/sf/ehcache/CacheException
需要加上:ehcache.jar
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异常8:
java.lang.NoClassDefFoundError: net/sf/cglib/core/KeyFactory
需要加上:cglib-full.jar

2. 加载出错

2.1 <context:property-placeholder>：Could not resolve placeholder XXX in string value XXX

当spring 配置多个properties 文件的时候需要特殊处理

方式1：

    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"><property name="locations"><list><value>classpath*:mongodb.properties</value><value>classpath*:xxx.properties</value><value>classpath*:bbb.properties</value></list></property><property name="ignoreUnresolvablePlaceholders" value="true" /> </bean>

方式2：

<context:property-placeholder location="classpath*:xxx.properties" ignore-unresolvable="true" />

PS :  重要属性：

<property name="ignoreUnresolvablePlaceholders" value="true" /> 　　 ignore-unresolvable="true"

2.2 Errors running builder 'DeploymentBuilder' on project_java

3 Other

在myeclipse中启动tomcat自动进入debug 解决方法