struts1 空指针异常，比较简单！ 有代码

struts1 空指针错误，比较简单！ 有代码！
   仅仅用了个struts1.2 做了个登录。  就出现空指针错误了。
   很是悲催。一直找不到，很无辜啊！！

javax.servlet.ServletException: java.lang.NullPointerException
	org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535)
	org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433)
	org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
	org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)


root cause 

java.lang.NullPointerException
	com.yourcompany.login.LoginAction.execute(LoginAction.java:19)
	org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
	org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
	org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

public class LoginAction extends Action {

	@Override
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		
		LoginForm loginForm=(LoginForm)form;
		if(loginForm.getLoginname().equals("qwe")){
			
			return mapping.findForward("LoginSuccess");
			
		}else{
			
			return mapping.findForward("LoginFail");
		}
	}
	
}

  这个是LOGINACTION 第十九行 用红色标记出来了。

public class LoginForm extends ActionForm {
	private String loginname=null;
	private String password=null;
	public String getLoginname() {
		return loginname;
	}
	public void setLoginname(String loginname) {
		this.loginname = loginname;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
}

 LoginForm。java

<struts-config>
  <data-sources />
  <form-beans>
  	<form-bean name="loginForm" type="com.yourcompany.login.LoginForm"></form-bean>
  </form-beans>
  
  <global-exceptions />
  <global-forwards />
  <action-mappings >
  	<action 
  	path="/login" type="com.yourcompany.login.LoginAction" name="loginForm">
  	<forward name="LoginSuccess" path="/loginsuccess.jsp"></forward>
  	<forward name="LoginFail"	 path="/loginfail.jsp"></forward>
  	</action>
  </action-mappings>
  <message-resources parameter="com.yourcompany.struts.ApplicationResources" />
</struts-config>

    struts-config.xml

 <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>