私の最初のStrutsプログラム

package com.test;
import org.apache.struts.action.*;
import javax.servlet.http.HttpServletRequest;
public class UserInfoForm extends ActionForm{
	private String username;
	private String password;
	public String getUsername(){return this.username;}
	public void setUsername(String username){this.username = username;}
	public String getPassword(){return (this.password);}
	public void setPassword(String password) {this.password = password;}
	}

package com.test;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;
public final class LoginAction extends Action
{
	public ActionForward execute(ActionMapping mapping,ActionForm form,HttpServletRequest request,
			HttpServletResponse response) throws IOException,ServletException
	{
		UserInfoForm loginInfoForm=(UserInfoForm)form;
		String username = loginInfoForm.getUsername().trim();
		String password=loginInfoForm.getPassword().trim();
		ActionErrors errors = new ActionErrors();
        if(username.equals("")){
        	ActionError error=new ActionError("error.missing.username");
        	errors.add(ActionErrors.GLOBAL_ERROR,error);
        	}
	    if(password.equals("")){
	    	ActionError error=new ActionError("error.missing.password");
	    	errors.add(ActionErrors.GLOBAL_ERROR,error);
	    }
	    if (errors.size()==0)
	    	{
	    	try{
                if (username.equals("lll") && password.equals("aaa"))
	    			return mapping.findForward("success");
                else
                {
                	ActionError error=new ActionError("error.wrong.userinfo");
                	errors.add(ActionErrors.GLOBAL_ERROR,error);
                }
	    	}catch(Throwable e){
	          e.printStackTrace();
	          ActionError error=new ActionError(e.getMessage());
	          errors.add(ActionErrors.GLOBAL_ERROR,error);
	          }
	}
	  saveErrors(request, errors);
	  return new ActionForward(mapping.getInput());
	}
	}