Question

错误是：

Servlet [StaffSystem]的Servlet.service（）在路径[/ StaffSystem]的上下文中引发了异常[请求处理失败;具有根本原因的嵌套异常是java.lang.NullPointerException] 显示java.lang.NullPointerException。

这是我的工具类：包com.etc.web.imp;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import com.etc.web.model.User;
import com.etc.web.service.UserService;

public class UserServiceImp implements UserService{

private JdbcTemplate jdbcTemplate;
@Override
public void save(User user) {
    // TODO Auto-generated method stub
     jdbcTemplate.update("insert into user(username,pwd) values (?,?)",new     Object[]{user.getUsername(),user.getPassword()});  
}

@Override
public void del(User user) {
    // TODO Auto-generated method stub

}

@Override
public void update(User user) {
    // TODO Auto-generated method stub

}

@Override
public void searchAll() {
    // TODO Auto-generated method stub
}
public JdbcTemplate getJdbcTemplate() {  
    return jdbcTemplate;  
}  

public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {  
    this.jdbcTemplate = jdbcTemplate;  
}

@Override
public List<User> searchLogin(String username){
    // TODO Auto-generated method stub
    List<User> users = null;
    Object[] params = new Object[] { username }; 
    String sql = "select * from user where username = ?";
    users =  (List<User>) jdbcTemplate.queryForObject(sql, params, new   UserRowMapper());
    return (users != null && users.size() > 0) ? users : null;
    }  
}

和服务类：包com.etc.web.service;

import java.util.List;

import com.etc.web.model.User;

public interface UserService {
    void save(User user);    
    void del(User user);    
    void update(User user);    
    void searchAll();
    List<User> searchLogin(String username);
}

接下来是控制器类：包com.etc.web.controller;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.etc.web.imp.UserServiceImp;
import com.etc.web.model.User;
import com.etc.web.service.UserService;

@Controller
@RequestMapping("/user")  
public class UserController {
    UserService userService;  
      @RequestMapping(value="/toIndex",method=RequestMethod.POST)  
        public ModelAndView toIndex (HttpServletRequest request){
          String username = request.getParameter("username");
          userService.searchLogin(username);
        return new ModelAndView("/index"); 
      }

}

RowMapper：包com.etc.web.imp;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.RowMapper;

import com.etc.web.model.User;

public class UserRowMapper implements RowMapper<User> {

    @Override
    public User mapRow(ResultSet rs, int value) throws SQLException {
    // TODO Auto-generated method stub
        User user = new User();
        user.setUsername(rs.getString("username"));
        user.setPassword(rs.getString("password"));
        return user;
    }   
}

最后这是我的xml：

<?xml version="1.0" encoding="UTF-8"?>
  <beans xmlns="http://www.springframework.org/schema/beans"    
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"    
    xmlns:context="http://www.springframework.org/schema/context"    
    xmlns:mvc="http://www.springframework.org/schema/mvc"    
    xsi:schemaLocation="     
           http://www.springframework.org/schema/beans     
           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd     
           http://www.springframework.org/schema/context     
           http://www.springframework.org/schema/context/spring-context-3.0.xsd    
           http://www.springframework.org/schema/mvc     
           http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> 

    <!-- 静态资源访问 -->
    <mvc:default-servlet-handler/>
    <!-- 扫描包 -->
    <context:component-scan base-package="com.etc.web.controller" />
    <!-- 添加注解驱动 -->  
    <mvc:annotation-driven />  

    <bean id="ViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <!-- apache.dbcp连接池的配置 -->  
    <bean id="dataSource"  
        class="org.apache.commons.dbcp.BasicDataSource"  
        destroy-method="close">  
        <property name="driverClassName"  
            value="com.mysql.jdbc.Driver">  
        </property>  
        <property name="url" value="jdbc:mysql://localhost:3306/test"></property>  
        <property name="username" value="root"></property>  
        <property name="password" value="123456"></property>  
        <property name="maxActive" value="100"></property>  
        <property name="maxIdle" value="30"></property>  
        <property name="maxWait" value="500"></property>  
        <property name="defaultAutoCommit" value="true"></property>  
    </bean>  

    <!-- jdbc注入 -->  
    <bean id="jdbcTemplate"  
        class="org.springframework.jdbc.core.JdbcTemplate">  
        <property name="dataSource">  
            <ref bean="dataSource" />  
        </property>  
    </bean>  

    <!-- dao注入 -->  
    <bean id="userService" class="com.etc.web.imp.UserServiceImp">  
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>  
    </bean>
   </beans>

我正在学习spring-mvc只有两天。这个问题困扰了我一整天。

jdbcTemplate查询（str，args []，RowMapper（））

0 个答案: