整合struts+spring+jpa中出现的解决方法

1. org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is java.lang.UnsupportedOperationException: Not supported by BasicDataSource

Spring不能为JPA创建事务。原因是spring-config.xml设定了数据源，persistence.xml中要把数据库连接去掉

     <property name="hibernate.connection.username" value="xxx"/>
     <property name="hibernate.connection.password" value="xxx"/>  
     <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/xxx?     useUnicode=true&amp;characterEncoding=UTF-8"/>

2. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'productServiceBean': Injection of persistence fields failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [beans.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: org.hibernate.MappingException: Could not determine type for: java.util.Set, for columns: [org.hibernate.mapping.Column(childtypes)]

原因：@Id @GeneratedValue(strategy = GenerationType.AUTO)
           这个注解写在get方法上不要写在属性声明上。

3. javax.persistence.PersistenceException: org.hibernate.exception.DataException: could not insert: [com.yufei.bean.product.ProductType]
 Caused by: java.sql.SQLException: Data too long for column 'visible' at row 1

原因：实体类字段中的visible插入到数据库中所对应的值为ASCII码味49，超出范围。
          换个mysql的jar包解决问题。

4. web容器出现

严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory

此问题多样化，查阅资料说是jar包commons-logging.jar问题 ,但解决的方式是重新导入项目...

5. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'productTypeService': Injection of persistence fields failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [beans.xml]: Invocation of init method failed; nested exception is java.lang.NoSuchMethodError: org.objectweb.asm.ClassVisitor.visit(IILjava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)V

原因： Spring2.5下asm-2.2.3.jar 与hibernate下的asm.jar 冲突， 删除asm-2.2.3.jar 。

6.  Failed to load or instantiate TagLibraryValidator class: org.apache.taglibs.standard.tlv.JstlCoreTLV

 org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:88)
org.apache.jasper.compiler.Parser.processIncludeDirective(Parser.java:340)
原因：lib中缺少standard.jar , jstl.jar
7. java.lang.NoSuchFieldError: DIRECTORY
 at net.fckeditor.connector.impl.AbstractLocalFileSystemConnector.getFolders(AbstractLocalFileSystemConnector.java:140)
 at net.fckeditor.connector.Dispatcher.getFoldersAndOrFiles(Dispatcher.java:204)
 at net.fckeditor.connector.Dispatcher.doGet(Dispatcher.java:156)
 at net.fckeditor.connector.ConnectorServlet.doGet(ConnectorServlet.java:89)

原因：包冲突，删掉struts1.3自带的commons-io-1.1.jar，commons-fileupload-1.1.1.jar，加入commons-io-1.3.2.jar，commons-fileupload-1.2.1.jar

8.IOException while loading persisted sessions: java.io.EOFException

java.io.EOFException
at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2281)
at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2750)
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:780)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:280)
原因是tomcat对硬盘的session读取失败，彻底解决办法一下：将work下面的文件清空，主要是*.ser文件，或者只是删除掉session.ser即可以解决。

9.javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist: com.dalton.domain.User

org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException

原因：(1) 是entity bean的 @Id标记错了,标记在了String 等类型上

(2) 对id字段手工设定了值。 

10 org.springframework.web.context.ContextLoader(line:215)  - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with
name 'brand' defined in file [D:\Tomcat6\webapps\autoet\WEB-INF\classes\com\autoet\
action\brand\BrandAction.class]: Instantiation of bean failed; nested exception is
org.springframework.beans.BeanInstantiationException: Could not instantiate bean
class [com.autoet.action.brand.BrandAction]: Constructor threw exception; nested
exception is java.lang.NullPointerException
原因：项目使用了<context:component-scan/>扫描机制, 而类BrandAction没有标注为原型,
为类添加 @Scope("prototype")标注(与@Controller相同位置)

11 org.hibernate.tool.hbm2ddl.SchemaUpdate(line:222)  - could not complete schema update
java.lang.UnsupportedOperationException: Not supported by BasicDataSource
原因 spring.xml 与 persistence.xml中都配置了数据库连接,注释掉persistence.xml中的连接信息

12 org.apache.struts2.dispatcher.Dispatcher(line:27)  - Dispatcher initialization failed
Unable to load configuration. - [unknown location]
Cannot locate the chosen ObjectFactory implementation: spring - [unknown location]
原因 struts.xml中使用了<constant name="struts.objectFactory" value="spring"/>，将其注释掉。