ognl.OgnlException: target is null for setProperty(null, "emailTypeNo", [Ljava.lang.String;@1513fd0)

[com.opensymphony.xwork2.ognl.OgnlValueStack] - Error setting expression 'emaiTypeDto.emailTypeNo' with value '[Ljava.lang.String;@1513fd0'
  ognl.OgnlException: target is null for setProperty(null, "emailTypeNo", [Ljava.lang.String;@1513fd0)
	at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:2309)
	at ognl.ASTProperty.setValueBody(ASTProperty.java:127)
	at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:220)
	at ognl.SimpleNode.setValue(SimpleNode.java:301)
	at ognl.ASTChain.setValueBody(ASTChain.java:227)
	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:317)
	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:228)
	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:236)
	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
	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 org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
	at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	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 org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
	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 com.manage.common.interceptor.LoginedCheckInterceptor.intercept(LoginedCheckInterceptor.java:50)
	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:511)
	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:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:185)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:151)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
	at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:269)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
	at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1773)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)

这种情况是在struts2高级的POJO访问时候出现的s

警告: Error setting expression 'user.password' with value '[Ljava.lang.String;@1cb2dd1' ognl.OgnlException: target is null for setProperty(null, "password", [Ljava.lang.String;@1cb2dd1)  at ognl.OgnlRuntime.setProperty(OgnlRuntime.Java:2219)

跟上面差不多的异常，我刚开始也遇到这个比较纠结的问题，下面我来说说我是如何解决的吧，可能大家遇到的跟我的不一样。但是这中间有几个地方需要注意，不然就会出现上面的错。

1、前台jsp

[java] view plaincopy

 

1. <body>
2. <form action="<%= path%>/login.action" method="post">
3. 用户名:<input type = "text" name = "user.username"><br/>
4. 密     码:<input type = "text" name = "user.password"><br/>
5. <input type = "submit" value = "login">
6. </form>
7. </body>

注意两个地方，一个是input里面的name要写成**.XX；这里的**就是你后面action中的一个类对象，小写就OK，我这里是一个user,还有就是这里是name=不是id=，如果是用id的话，好像是传不到action中去的。

2、action类

[java] view plaincopy

 

1. public class Login extends ActionSupport {
2. public User getUser() {
3. return user;
4. }
5. public void setUser(User user) {
6. this.user = user;
7. }
8. private User user = new User();
9. @Override
10. public String execute() throws Exception {
11. System.out.println("username="+user.getUsername()+",password="+user.getPassword());
12. return SUCCESS;
13. }
14. }

user类

[c-sharp] view plaincopy

 

1. public class User {
2. private String username;
3. private String password;
4. public String getUsername() {
5. return username;
6. }
7. public void setUsername(String username) {
8. this.username = username;
9. }
10. public String getPassword() {
11. return password;
12. }
13. public void setPassword(String password) {
14. this.password = password;
15. }
16. }

action中的 user类必须得new，如果不new会报空指针(除非你已经配好spring，让spring给你做这件事)

再一个就是必须得有get/set方法，user的get/set方法。

struts.xm;

[java] view plaincopy

 

1. <package name="login"  extends="struts-default">
2. <action name="login" class="com.ssh2.action.Login">
3. <result name="success" type="redirect">/index.jsp</result>
4. <result name="error" type = "redirect">/login.jsp</result>
5. </action>
6. </package>

注意上面几点就没问题了。

我的问题出现的原因是：请求的action错误了，所以出现了这个问题。