tangxininjava

struts2错误source is null for getProperty(null, "0")

首先简单描述下：

首先我用的springside-3.3.4中的CrudActionSupport 用简单的对象（意思是对象里面没有对象就不会报错，而对象里面有对象的就会报错，我里面用了List）

我先说下对象关系吧用代码：

package com.tang.flight.vo.custom;

import java.util.List;

import com.tang.flight.vo.DomeTicketFlight;
import com.tang.flight.vo.ThirdPolicyItem;

public class OrderVo {
	
	private String orderNo;
	
	
	public String getOrderNo() {
		return orderNo;
	}

	public void setOrderNo(String orderNo) {
		this.orderNo = orderNo;
	}

	private List<DomeTicketFlight> flights;
	
	private List<ThirdPolicyItem> thirdPolicyItems;

	public List<DomeTicketFlight> getFlights() {
		return flights;
	}

	public void setFlights(List<DomeTicketFlight> flights) {
		this.flights = flights;
	}

	public List<ThirdPolicyItem> getThirdPolicyItems() {
		return thirdPolicyItems;
	}

	public void setThirdPolicyItems(List<ThirdPolicyItem> thirdPolicyItems) {
		this.thirdPolicyItems = thirdPolicyItems;
	}
	
	

}

package com.tang.flight.actions.order;

import java.util.ArrayList;

import org.apache.struts2.convention.annotation.Namespace;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;

import com.tang.flight.actions.CrudActionSupport;
import com.tang.flight.vo.DomeTicketFlight;
import com.tang.flight.vo.ThirdPolicyItem;
import com.tang.flight.vo.custom.OrderVo;

@Namespace("/order")
@Results({@Result(type="redirect",location="manager.action",name=CrudActionSupport.RELOAD)})
public class ManagerAction extends CrudActionSupport<OrderVo> {

	private static final long serialVersionUID = -6137449398836451112L;
	
	
	private Long id;
	
	
	
	
	public void setId(Long id) {
		this.id = id;
	}

	private OrderVo entity;
	
	
	@Override
	public String delete() throws Exception {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String input() throws Exception {
		// TODO Auto-generated method stub
		return INPUT;
	}

	@Override
	public String list() throws Exception {
		// TODO Auto-generated method stub
		return SUCCESS;
	}

	@Override
	protected void prepareModel() throws Exception {
		if (id!=null) {
			
		}else{
			entity = new OrderVo();
			ArrayList<DomeTicketFlight> flights = new ArrayList<DomeTicketFlight>(0);
			flights.add(new DomeTicketFlight());
			entity.setFlights(flights);
			ArrayList<ThirdPolicyItem> thirdPolicyItems = new ArrayList<ThirdPolicyItem>(0);
			thirdPolicyItems.add(new ThirdPolicyItem());
			entity.setThirdPolicyItems(thirdPolicyItems);
		}
		
	}

	@Override
	public String save() throws Exception {
		// TODO Auto-generated method stub
		System.out.println(entity);
		return RELOAD;
	}

	public OrderVo getModel() {
		// TODO Auto-generated method stub
		return entity;
	}

	
	

}

<#assign s=JspTaglibs["/WEB-INF/struts-tags.tld"] />
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'index.jsp' starting page</title>
  </head>
  <body>
	<h1></h1>
	<@s.form action="manager!save.action" theme="simple">
		<@s.textfield label="fltNo" title="fltNo"  name="flights[0].fltNo"   theme="simple"/>
		<@s.textfield title="fltNo" name="thirdPolicyItems[0].protocolNo" theme="simple" />
		<@s.textfield label="orderNo" title="orderNo"  name="orderNo"   theme="simple"/>
		<@s.submit theme="simple"/>
	</@s.form>
	
	
	
  </body>
</html>

save方法保存之前会执行

@Override
	protected void prepareModel() throws Exception {
		if (id!=null) {
			
		}else{
			entity = new OrderVo();
			ArrayList<DomeTicketFlight> flights = new ArrayList<DomeTicketFlight>(0);
			flights.add(new DomeTicketFlight());
			entity.setFlights(flights);
			ArrayList<ThirdPolicyItem> thirdPolicyItems = new ArrayList<ThirdPolicyItem>(0);
			thirdPolicyItems.add(new ThirdPolicyItem());
			entity.setThirdPolicyItems(thirdPolicyItems);
		}
		
	}

很奇怪这里面的entity是空的，然后到下面这个方法时又不是空的

@Override
	public String save() throws Exception {
		// TODO Auto-generated method stub
		System.out.println(entity);
		return RELOAD;
	}

下面的这个错误是在prepareModel这个方法报的

2013-01-24 14:33:46,170 [http-8083-1] WARN [com.opensymphony.xwork2.ognl.OgnlValueStack] - Error setting expression 'flights[0].fltNo' with value '[Ljava.lang.String;@179d47f'

ognl.OgnlException: source is null for getProperty(null, "0")

at ognl.OgnlRuntime.getProperty(OgnlRuntime.java:2293)

at ognl.ASTProperty.getValueBody(ASTProperty.java:114)

at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)

at ognl.SimpleNode.getValue(SimpleNode.java:258)

at ognl.ASTChain.setValueBody(ASTChain.java:222)

at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:220)

at ognl.SimpleNode.setValue(SimpleNode.java:301)

at ognl.Ognl.setValue(Ognl.java:737)

at com.opensymphony.xwork2.ognl.OgnlUtil.setValue(OgnlUtil.java:217)

at com.opensymphony.xwork2.ognl.OgnlValueStack.trySetValue(OgnlValueStack.java:186)

at com.opensymphony.xwork2.ognl.OgnlValueStack.setValue(OgnlValueStack.java:173)

at com.opensymphony.xwork2.ognl.OgnlValueStack.setParameter(OgnlValueStack.java:151)

at com.opensymphony.xwork2.interceptor.ParametersInterceptor.setParameters(ParametersInterceptor.java:292)

at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:203)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:192)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at org.apache.struts2.interceptor.MessageStoreInterceptor.intercept(MessageStoreInterceptor.java:194)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)

at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)

at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:510)

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 org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)

at java.lang.Thread.run(Thread.java:662)

2013-01-24 14:33:46,173 [http-8083-1] WARN [com.opensymphony.xwork2.ognl.OgnlValueStack] - Error setting expression 'thirdPolicyItems[0].protocolNo' with value '[Ljava.lang.String;@22ed4b'