用ssh2，把表单提交给action时出现空异常

Question

1.查看下Department 有没有提供无参构造方法(是不是只写了有参构造)
2.Department 类中是否提供了对应属性的setter方法

Answer 1

这里是异常信息：
谁帮的看看错在哪里了
DEBUG (ServletDispatcherResult.java:113) - Forwarding to location /department/error.jsp
DEBUG (InstantiatingNullHandler.java:72) - Entering nullPropertyValue [target=[com.opensymphony.xwork2.DefaultTextProvider@c5f20f], property=struts]
DEBUG (DefaultActionProxy.java:65) - Creating an DefaultActionProxy for namespace /action and action name addDepartmentAction
DEBUG (ParametersInterceptor.java:142) - Setting params department.departmentName => [ 你好 ] department.parentDepartmentId => [  ] 
DEBUG (XWorkConverter.java:392) - Property: departmentName
DEBUG (XWorkConverter.java:393) - Class: entity.Department
DEBUG (XWorkConverter.java:282) - field-level type converter for property [departmentName] = none found
DEBUG (XWorkConverter.java:392) - Property: department.departmentName
DEBUG (XWorkConverter.java:393) - Class: action.AddDepartmentAction
DEBUG (XWorkConverter.java:306) - global-level type converter for property [departmentName] = none found
DEBUG (XWorkConverter.java:324) - falling back to default type converter [com.opensymphony.xwork2.util.XWorkBasicConverter@229ed4]
DEBUG (XWorkConverter.java:392) - Property: parentDepartmentId
DEBUG (XWorkConverter.java:393) - Class: entity.Department
DEBUG (XWorkConverter.java:282) - field-level type converter for property [parentDepartmentId] = none found
DEBUG (XWorkConverter.java:392) - Property: department.parentDepartmentId
DEBUG (XWorkConverter.java:393) - Class: action.AddDepartmentAction
DEBUG (XWorkConverter.java:306) - global-level type converter for property [parentDepartmentId] = none found
DEBUG (XWorkConverter.java:324) - falling back to default type converter [com.opensymphony.xwork2.util.XWorkBasicConverter@229ed4]
DEBUG (ValidationInterceptor.java:134) - Validating /action/addDepartmentAction with method execute.
DEBUG (DefaultActionInvocation.java:378) - Executing action method = null
java.lang.NullPointerException
at action.AddDepartmentAction.execute(AddDepartmentAction.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:399)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:262)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:224)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.intercept(ParametersInterceptor.java:161)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:50)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:507)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Thread.java:595)

Answer 2

这里是Department类:
package entity;/**
 * Department entity.
 * 
 * @author MyEclipse Persistence Tools
 */public class Department implements java.io.Serializable { // Fields private Integer departmentId;
private String departmentName;
private Integer parentDepartmentId; // Constructors /** default constructor */
public Department() {
} /** minimal constructor */
public Department(String departmentName) {
this.departmentName = departmentName;
} /** full constructor */
public Department(String departmentName, Integer parentDepartmentId) {
this.departmentName = departmentName;
this.parentDepartmentId = parentDepartmentId;
} // Property accessors public Integer getDepartmentId() {
return this.departmentId;
} public void setDepartmentId(Integer departmentId) {
this.departmentId = departmentId;
} public String getDepartmentName() {
return this.departmentName;
} public void setDepartmentName(String departmentName) {
this.departmentName = departmentName;
} public Integer getParentDepartmentId() {
return this.parentDepartmentId;
} public void setParentDepartmentId(Integer parentDepartmentId) {
this.parentDepartmentId = parentDepartmentId;
}}这两项都满足啊:
  1.查看下Department 有没有提供无参构造方法(是不是只写了有参构造) 
  2.Department 类中是否提供了对应属性的setter方法

Answer 3

      页面的请求路径写的对吗? 比如/login.do  设个断点调试下.

Answer 4

      页面的请求路径写的对吗? 比如/login.do  设个断点调试下.

Answer 5

我看异常里有一个field-level type converter for property [departmentName] = none found 大概意思是字段类型的装换器没有找到但是我看了别人的ssh2的例子，写的和我的没有区别
我再贴一次代码：1.表单部分
<s:form action="/action/addDepartmentAction.action" name="operationForm">
<s:textfield name="department.departmentName" label="部门名称" value=""></s:textfield>
<s:textfield name="department.parentDepartmentId" label="上级部门" value=""></s:textfield>
<s:submit value="登录"></s:submit>
</s:form>2.web.xml 
<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="2.4" 
xmlns="http://java.sun.com/xml/ns/j2ee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> 
<context-param> 
        <param-name>contextConfigLocation </param-name> 
        <param-value>/WEB-INF/applicationContext.xml </param-value> 
    </context-param> 
<filter> 
<filter-name>struts2 </filter-name> 
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher </filter-class> 
</filter> 
<!-- FilterDispatcher-strtus2--> 
<filter-mapping> 
<filter-name>struts2 </filter-name> 
<url-pattern>/* </url-pattern> 
</filter-mapping> 
<listener> 
    <listener-class>org.springframework.web.context.ContextLoaderListener </listener-class> 
</listener> 
</web-app> 3.struts.xml 
<!DOCTYPE struts PUBLIC 
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" 
        "http://struts.apache.org/dtds/struts-2.0.dtd"> 
<struts> 
    <package name="action" extends="struts-default" namespace="/action"> 
        <action name="addDepartmentAction" class="action.AddDepartmentAction"> 
            <result name="success">/department/succeed.jsp </result> 
            <result name="error">/department/error.jsp </result> 
        </action> 
    </package> 
</struts> 4.这里是Department类: 
package entity; /** 
* Department entity. 
* 
* @author MyEclipse Persistence Tools 
*/ public class Department implements java.io.Serializable { // Fields private Integer departmentId; 
private String departmentName; 
private Integer parentDepartmentId; // Constructors /** default constructor */ 
public Department() { 
} /** minimal constructor */ 
public Department(String departmentName) { 
this.departmentName = departmentName; 
} /** full constructor */ 
public Department(String departmentName, Integer parentDepartmentId) { 
this.departmentName = departmentName; 
this.parentDepartmentId = parentDepartmentId; 
} // Property accessors public Integer getDepartmentId() { 
return this.departmentId; 
} public void setDepartmentId(Integer departmentId) { 
this.departmentId = departmentId; 
} public String getDepartmentName() { 
return this.departmentName; 
} public void setDepartmentName(String departmentName) { 
this.departmentName = departmentName; 
} public Integer getParentDepartmentId() { 
return this.parentDepartmentId; 
} public void setParentDepartmentId(Integer parentDepartmentId) { 
this.parentDepartmentId = parentDepartmentId; 
} } 5.action 
package action; 
import com.opensymphony.xwork2.Action; 
import entity.Department; 
import service.DepartmentService; 
public class AddDepartmentAction implements Action 
{ 
private Department department=new Department(); 
private DepartmentService departmentService; 
public void setDepartment(Department department){ 
this.department=department; 
} 
public Department getDepartment(){ 
return department; 
} 
public DepartmentService getDepartmentService(){ 
return departmentService; 
} 
public void setDepartmentService(DepartmentService departmentService){ 
this.departmentService=departmentService; 
} 
public String execute() throws Exception 
{ 
//department=new Department(); 
try { 
departmentService.addDepartment(department); 
return "success"; 
} catch (Exception e) { 
e.printStackTrace(); 
return "error"; 
} 
} 
}6.这里是异常信息： 
谁帮的看看错在哪里了 
DEBUG (ServletDispatcherResult.java:113) - Forwarding to location /department/error.jsp 
DEBUG (InstantiatingNullHandler.java:72) - Entering nullPropertyValue [target=[com.opensymphony.xwork2.DefaultTextProvider@c5f20f], property=struts] 
DEBUG (DefaultActionProxy.java:65) - Creating an DefaultActionProxy for namespace /action and action name addDepartmentAction 
DEBUG (ParametersInterceptor.java:142) - Setting params department.departmentName => [ 你好 ] department.parentDepartmentId => [  ] 
DEBUG (XWorkConverter.java:392) - Property: departmentName 
DEBUG (XWorkConverter.java:393) - Class: entity.Department 
DEBUG (XWorkConverter.java:282) - field-level type converter for property [departmentName] = none found 
DEBUG (XWorkConverter.java:392) - Property: department.departmentName 
DEBUG (XWorkConverter.java:393) - Class: action.AddDepartmentAction 
DEBUG (XWorkConverter.java:306) - global-level type converter for property [departmentName] = none found 
DEBUG (XWorkConverter.java:324) - falling back to default type converter [com.opensymphony.xwork2.util.XWorkBasicConverter@229ed4] 
DEBUG (XWorkConverter.java:392) - Property: parentDepartmentId 
DEBUG (XWorkConverter.java:393) - Class: entity.Department 
DEBUG (XWorkConverter.java:282) - field-level type converter for property [parentDepartmentId] = none found 
DEBUG (XWorkConverter.java:392) - Property: department.parentDepartmentId 
DEBUG (XWorkConverter.java:393) - Class: action.AddDepartmentAction 
DEBUG (XWorkConverter.java:306) - global-level type converter for property [parentDepartmentId] = none found 
DEBUG (XWorkConverter.java:324) - falling back to default type converter [com.opensymphony.xwork2.util.XWorkBasicConverter@229ed4] 
DEBUG (ValidationInterceptor.java:134) - Validating /action/addDepartmentAction with method execute. 
DEBUG (DefaultActionInvocation.java:378) - Executing action method = null 
java.lang.NullPointerException 
at action.AddDepartmentAction.execute(AddDepartmentAction.java:25) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:585) 

Answer 6

问题解决了
1.不一定要struts-default.xml也可以2.关于struts
<struts> 
    <package name="action" extends="struts-default" namespace="/action"> 
        <action name="addDepartmentAction" class="action.AddDepartmentAction"> 
            <result name="success">/department/succeed.jsp </result> 
            <result name="error">/department/error.jsp </result> 
        </action> 
    </package> 
</struts> 
class不能是类的物理位置，而应该是applictionContext.xml里action对应的id3.还需要struts2-spring-plugin2.0.6包4.表单的提交保存也可以用“模型驱动”来解决，这样表单内的文本框可以从“对象名.属性名”简化为“属性名”，我还没有尝试，但效果都是一样的，都比struts1要分解表单的每一项要简单。