Spring MVC篇二、使用JdbcTemplate進行數據庫操作

上一篇只是一個簡單的Spring MVC框架，接下來添加一些跟數據庫的交互。

一、添加jdbc相關配置

 

在maven中添加相關依賴后，配置數據庫訪問參數及數據源。數據庫參數使用配置文件，代碼如下：

jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/sampledb
jdbc.username=root
jdbc.password=123456
jdbc.initialSize=5
jdbc.maxActive=10
jdbc.minIdle=5
jdbc.maxIdle=10
jdbc.timeBetweenEvictionRunsMillis=3600000
jdbc.minEvictableIdleTimeMillis=3600000
jdbc.testOnBorrow=true
jdbc.validationQuery=SELECT 1 FROM DUAL

 

在app-servlet.xml中添加數據源配置和jdbcTemplate配置：

<bean id="jdbcConfig" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>classpath:jdbc.properties</value>
    </property>
</bean>
<bean id="databasesource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="${jdbc.driver}"/>
    <property name="url" value="${jdbc.url}"/>
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
    <property name="maxActive" value="${jdbc.maxActive}"/>
    <property name="initialSize" value="${jdbc.initialSize}"/>
    <property name="maxIdle" value="${jdbc.maxIdle}"/>
    <property name="minIdle" value="${jdbc.minIdle}"/>
    <property name="timeBetweenEvictionRunsMillis"     value="${jdbc.timeBetweenEvictionRunsMillis}"/>
    <property name="minEvictableIdleTimeMillis" value="${jdbc.minEvictableIdleTimeMillis}"/>
    <property name="testOnBorrow" value="${jdbc.testOnBorrow}"/>
    <property name="validationQuery" value="${jdbc.validationQuery}"/>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="databasesource"/>
</bean>

 

二、實現一個使用用戶名為super，密碼為123456的用戶登錄過程

2.1 添加User實體類

User.java代碼如下：

public class User {
    private Long id;
    private String username;
    private String email;
    private String password;
    private Long credit;
    private Date lastVisitTime;
    private String lastVisitIp;
    //setter、getter
}

 

2.2 實現對數據庫的訪問操作

新建UserDao.java，在UserDao類上添加@Repository注解

首先在該類中裝配JdbcTemplate，使用@Autowired注解

@Autowired
private JdbcTemplate jdbcTemplate;

 

然后在里面添加一個根據用戶名和密碼查詢用戶的方法：

public User findUser(final String username, final String password) {
        String sql = "select id,user_name, credit from t_user_info where user_name = ? and password = ?";
        User user = null;
        try {
            RowMapper<User> rm = ParameterizedBeanPropertyRowMapper.newInstance(User.class);
            user = (User) jdbcTemplate.queryForObject(sql, new Object[]{username, password}, rm);
        }catch (Exception e){
            e.printStackTrace();
        }
        return user;
    }

 

2.3 添加UserService.java類，代碼如下：

@Service("userService")
public class UserService {
    @Autowired
    UserDao userDao;
    public User findUser(String username,String password){
        return userDao.findUser(username,password);
    }

    public int findUserCount(String username,String password){
        return userDao.findUserCount(username,password);
    }

    public boolean insertUser(User user){
        return userDao.insertUser(user);
    }
}

 

2.4 修改UserController.java的userIndex方法：

@RequestMapping(value = "/index.html", method = RequestMethod.POST)
    public ModelAndView userIndex(String username, String password) {
        if (StringUtil.isEmpty(username) || StringUtil.isEmpty(password)) {
            logger.error("用戶名或密碼為空");
            ModelAndView modelAndView = new ModelAndView("/index");
            modelAndView.addObject("error", "用戶名或密碼為空！");
            return modelAndView;
        }

//        int count = userService.findUserCount(username,password);
        User user = userService.findUser(username, password);
        if (user == null) {
            logger.info("用戶名或密碼錯誤");
            ModelAndView modelAndView = new ModelAndView("/index");
            modelAndView.addObject("username", username);
            modelAndView.addObject("error", "用戶：" + username + "不存在或用戶密碼錯誤！");
            return modelAndView;
        }
        ModelAndView mav = new ModelAndView("success");
        mav.addObject("username", username);
        mav.addObject("password", password);
        logger.info("username : " + username + ", password : " + password);
        return mav;
    }

 

這樣就實現了登錄的簡單流程。