hibernate 关联查询报错

java代码如下//查询的hql
StringBuffer hql = new StringBuffer("select d,p from DriverInfo d,Parameter p where d.licenseType = p.id.paramKey And p.id.paramType = ? ");
//存入字段
ArrayList<Object> param = new ArrayList<Object>();
param.add("licenseType");
if(name!=null && !name.equals("")){
hql.append(" And d.name = ?");
param.add(name);
}
if(driverLicense!=null && !driverLicense.equals("")){
hql.append(" And d.driverLicense = ?");
param.add(driverLicense);
}

List<Object> drivers = (List<Object>) this.queryForPage(hql.toString(),param, offset, length);

List<DriverInfo> drs = null ;

for(int i=0 ;i<drivers.size();i++){
Object[] ob =(Object[]) drivers.get(i);
System.out.println(ob[0]);
DriverInfo driver =(DriverInfo) ob[0]; //报错行
Parameter parame = (Parameter) ob[1];
driver.setLicenseType(parame.getParamValue());
drs.add(driver);
}
return drs;调用的方法：public List<?> queryForPage(final String hql,final ArrayList<Object> param,final int offset, final int length)
{
List<?> list = getHibernateTemplate().executeFind(new HibernateCallback()
{
public Object doInHibernate(Session session) throws HibernateException, SQLException
{
Query query = session.createQuery(hql);
//插入查询条件
if(param.size()>0){
for(int i=0;i<param.size();i++){
query.setParameter(i, param.get(i));
}
}
//设置分页
query.setFirstResult(offset);
query.setMaxResults(length);
List<?> list = query.list();
return list;
}
});
return list;
}错误：2011-10-12 00:16:01,932 DEBUG [http-8080-3] (SQLStatementLogger.java:111) - select driverinfo0_.DRIVER_ID as DRIVER1_7_0_, parameter1_.PARAM_TYPE as PARAM1_11_1_, parameter1_.PARAM_KEY as PARAM2_11_1_, driverinfo0_.NAME as NAME7_0_, driverinfo0_.PHONE as PHONE7_0_, driverinfo0_.DRIVER_LICENSE as DRIVER4_7_0_, driverinfo0_.LICENSE_TYPE as LICENSE5_7_0_, driverinfo0_.LICENSE_YEAR as LICENSE6_7_0_, driverinfo0_.NOTE as NOTE7_0_, parameter1_.PARAM_VALUE as PARAM3_11_1_, parameter1_.PARAM_DESC as PARAM4_11_1_ from transport.tb_driver_info driverinfo0_, transport.tb_parameter parameter1_ where driverinfo0_.LICENSE_TYPE=parameter1_.PARAM_KEY and parameter1_.PARAM_TYPE=? limit ?
java.lang.NullPointerException
at lxt.action.DriverAction.loadAll(DriverAction.java:54)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:485)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at lxt.action.core.LoginFilter.doFilter(LoginFilter.java:37)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
at java.lang.Thread.run(Unknown Source)
我参照网上的写法,地址：
http://www.xker.com/page/e2009/0925/79902.html
但不明白哪里不对，请高手指点。

解决方案 »

  1.   

    好像这并不是hibernate出错，而是struts2出错噢。
      

  2.   

    找到原因
    是List<DriverInfo> drs = null ;没有初始化，但是现在发现一个新的问题
    DriverInfo driver =(DriverInfo) ob[0];
    Parameter parame = (Parameter) ob[1];
    driver.setLicenseType(parame.getParamValue());
    这里怎么直接把数据库里的信息改变了啊？
    我的需求是在页面显示的时候显示
    parame.getParamValue()的值
    要怎么做啊？
      

  3.   


    DAO里面有session容器，从数据库中查询出来的身体，在session容器中都是PO，对PO修改会被更新到数据库中
    脱离session，转换成VO再修改就可以了
      

  4.   

    在service里修改就可以了是吧
    哈哈
    谢谢