日期:2014-05-17  浏览次数:20696 次

紧急求助SSH查询出现空指针错误
谢了一个SSH的查询,但是执行之后页面上报空指针错误!求解:
Java code

1.noticeDaoImpl.java

package com.HRM.dao.Impl;

import java.util.List;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.HRM.dao.noticeDao;
import com.HRM.entity.Notice;

public class noticeDaoImpl extends HibernateDaoSupport implements noticeDao {

    @Override
    public List<Notice> findAllNotice() {
        List<Notice> list = getHibernateTemplate().find("from Notice");
        return list;
    }
    
}


2.noticeServiceImpl.java

package com.HRM.Service.Impl;

import java.util.List;

import com.HRM.dao.noticeDao;
import com.HRM.entity.Notice;
import com.opensymphony.xwork2.ActionSupport;

public class noticeServiceImpl extends ActionSupport implements noticeService{
    private noticeDao ndao;
    

    @Override
    public List<Notice> findAllNotice() {
        return ndao.findAllNotice();
    }
    
    
    

    public noticeDao getNdao() {
        return ndao;
    }
    public void setNdao(noticeDao ndao) {
        this.ndao = ndao;
    }

}

3.noticeAction.java

package com.HRM.action;

import java.util.List;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.HRM.Service.Impl.noticeService;
import com.HRM.entity.Notice;
import com.opensymphony.xwork2.ActionSupport;

public class noticeAction extends ActionSupport {
    private noticeService nser;
    
    
    HttpSession session = ServletActionContext.getRequest().getSession();
    @Override
    public String execute() throws Exception {
        List<Notice> list = nser.findAllNotice();
        if(list.size()>0){
            session.setAttribute("notice",list);
            return SUCCESS;
        }
        return ERROR;
    }
    public noticeService getNser() {
        return nser;
    }
    public void setNser(noticeService nser) {
        this.nser = nser;
    }
}





运行之后说是 noticeAction。java中List<Notice> list = nser.findAllNotice(); 是空指针!




求解啊大侠们

------解决方案--------------------
断点调试一下 List里面有没有值啊
------解决方案--------------------
List<Notice> list = getHibernateTemplate().find("from Notice");
说明这句没查出值。

------解决方案--------------------
断点调试一下 List里面有没有值啊