常见异常处理办法

1. getOutputStream() has already been called for this response

jsp文件末尾添加两句话

out.clear();
out = pageContext.pushBody();

 

2. java.lang.IncompatibleClassChangeError: Expecting non-static method

原因可能是静态方法没有用静态的方式去访问

 

3. java.lang.IllegalStateException

在response.sendRedirect("")方法后加return;语句即可，原因是在程序中两次调用response.sendRedirect("")方法

 

4.NoClassDefFoundError: com/sun/mail/util/LineInputStream

javax.mail和javax.activation这两个包已经在javaEE5的javaee.jar当中属于基础包了，与外部引用的mail.jar冲突

 

5 struts2 iterator

 java.lang.Integer cannot be cast to java.lang.String

使用的时候在前面加上#，如<s:property value='#id' />

 

6 Struts中the request was rejected because its size (***) exceeds the configured maximum (2097152)

struts.xml中加上如下配置

<constant name="struts.multipart.maxSize" value="10485760" />

 

7 failed to lazily initialize a collection of role: no session or session was closed

web.xml中添加如下代码，并且要添加在struts2的filter的前面

<filter>
   <filter-name>hibernateFilter</filter-name>
   <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
   <init-param>
           <param-name>singleSession</param-name>
           <param-value>true</param-value>
       </init-param>
  </filter>
  <filter-mapping>
   <filter-name>hibernateFilter</filter-name>
   <url-pattern>/*</url-pattern>
  </filter-mapping>

 

8 mysql存中文的时候报错 data too long

mysql数据库字符集设置有问题，用show variables like 'character_%'查看数据库字符集

 

9  tomcat报错：SEVERE: Error listenerStart

是其他错误引起的这个错，例如FileNotFoundException等等

tomcat没有显示具体错误，可以在classes下面新建logging.properties文件用来监控具体错误信息

 

handlers = org.apache.juli.FileHandler, java.util.logging.ConsoleHandler  

 

############################################################  

# Handler specific properties.  

# Describes specific configuration info for Handlers.  

############################################################  

 

org.apache.juli.FileHandler.level = FINE  

org.apache.juli.FileHandler.directory = ${catalina.base}/logs  

org.apache.juli.FileHandler.prefix = error-debug.  

 

java.util.logging.ConsoleHandler.level = FINE  

java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter  

 

10 Caused by: java.lang.ClassCastException: org.apache.xerces.parsers.XML11Configuration cannot be cast to org.apache.xerces.xni.parser.XMLParserConfiguration

 

项目xerces.jar和tomcat自带的包可能有冲突，可以将项目内的xerces.jar去掉试试

 

 

11  ssh项目tomcat启动时spring报错   could not resolve placeholder

 

<bean id="placeholderConfig"

class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

<property name="location">

<value>classpath:init.properties</value>

</property>

<property name="ignoreUnresolvablePlaceholders" value="true" />

</bean>

解决办法如上加入<property name="ignoreUnresolvablePlaceholders" value="true" />

 

12 invalid subscription level

解决办法：

Window->Preferences->Myeclipse Enterprise Workbench->Subscription

填写相应myeclipse注册码即可

 

13 ssh中hibernate自动创建表时报错  check the manual that corresponds to your MySQL server version for the right syntax to use near 'type=MyISAM' at line 1

查看hibernate方言设置，把org.hibernate.dialect.MySQLMyISAMDialect改为org.hibernate.dialect.MySQLDialect

 

14 Myeclipse 报错 Refresh property sheet

 Windows > Preferences > MyEclipse > Community Essentials, 

把选项 "Search for new features on startup"的前勾去掉即可.