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>

 &nb