Spring JDBC数据库开发

针对数据库操作，Spring框架提供了JdbcTemplate类。

1.Spring JDBC的配置

创建配置文件applicationContext.xml，添加如下代码：

 　　　<!--配置数据源-->
     <bean id="dataSource"
           class="org.springframework.jdbc.datasource.DriverManagerDataSource">
         <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
         <property name="url" value="jdbc:mysql://localhost:3306/springjdbc"/>
         <property name="username" value="root"/>
         <property name="password" value="root"/>
     </bean>
     <!--配置JDBC模板-->
     <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
         <property name="dataSource" ref="dataSource"/>
     </bean>
     <!--配置注入类-->
     <bean id="userDao" class="com.wxy.model.UserDaoImpl">
         <property name="jdbcTemplate" ref="jdbcTemplate"/>
     </bean>

2.创建Javabean和Dao接口

 public class User {
     private Integer id;
     private String name;
     private Integer age;
 
     public Integer getId() {  return id; }
 
     public void setId(Integer id) {
         this.id = id;
     }
 
     public String getName() {
         return name;
     }
 
     public void setName(String password) {
         this.name = password;
     }
 
     public Integer getAge() { return age; }
 
     public void setAge(Integer age) {
         this.age = age;
     }
 }

javabean

public interface UserDao {
    public void execute();
    public int addUser(User user);
    public int updateUser(User user);
    public int deleteUser(int id);
    public void query();
}

UserDao

3.Spring JdbcTemplate的常用方法

2.1 execute(String sql)执行SQL语句

2.2 update()插入、更新、删除表数据操作

2.3 query()查询操作

上述的三个数据库操作方法都放在UserDaoImpl实现类中调用，具体代码如下：

 import com.wxy.javabean.User;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.ResultSetExtractor;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
 
 public class UserDaoImpl implements UserDao {
     //获取JdbcTemplate实例
     private JdbcTemplate jdbcTemplate;
14     public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
15         this.jdbcTemplate = jdbcTemplate;
16     }
     //执行SQL语句的方法
     @Override
     public void execute() {
         jdbcTemplate.execute("create table account( id int primary key auto_increment,"
                 + "username varchar(50)," + "balance double)");
     }
     //添加用户
     @Override
     public int addUser(User user) {
         String sql = "insert user (id,name,age) value(?,?,?)";
         //定义数组来存储SQL语句中的参数
         Object[] obj = new Object[]{
                 user.getId(),
                 user.getName(),
                 user.getAge()
         };
         int num = this.jdbcTemplate.update(sql,obj);
         return num;
     }
     //更新用户信息
     public int updateUser(User user){
         String sql = "update user set name=?,age=? where id=?";
         Object[] params = new Object[]{
                 user.getName(),
                 user.getAge(),
                 user.getId()
         };
         int num = this.jdbcTemplate.update(sql,params);
         return num;
     }
     //删除用户
     @Override
     public int deleteUser(int id) {
         String sql = "delete from user where id =?";
         int num = jdbcTemplate.update(sql,id);
         return num;
     }
     //查询所有用户
     @Override
     public void query() {
         String listSql = "select * from user";
         List<User> list = jdbcTemplate.query(listSql, new ResultSetExtractor<List>() {
             public List<User> extractData(ResultSet rs) throws SQLException,
                     DataAccessException {
                 List<User> result = new ArrayList<User>();
                 while (rs.next()) {
                     User user = new User();
                     user.setId(rs.getInt("id"));
                     user.setName(rs.getString("name"));
                     user.setAge(rs.getInt("age"));
                     result.add(user);
                 }
                 return result;
             }
         });
 
         for (User user : list) {
             System.out.print("id=" + user.getId() + " ");
             System.out.print("name=" + user.getName() + " ");
             System.out.println("age=" + user.getAge() + " ");
         }
     }
 }

4.编写测试类Test

 import com.wxy.javabean.User;
 import com.wxy.model.UserDaoImpl;
 import org.junit.Test;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 
 public class JdbcTemplateTest {
     @Test
     public void executeTest(){
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
         UserDaoImpl userDao = (UserDaoImpl) applicationContext.getBean("userDao");
         userDao.execute();
         System.out.println("创建成功！");
     }
     @Test
     public void addTest(){
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
         UserDaoImpl userDao = (UserDaoImpl) applicationContext.getBean("userDao");
         User user = new User();
         user.setId(3);
         user.setName("Tom");
         user.setAge(21);
         int num = userDao.addUser(user);
         if(num>0){
             System.out.println("成功添加"+num+"个用户");
         }else {
             System.out.println("添加用户操作失败！");
         }
     }
     @Test
     public void updateTest(){
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
         UserDaoImpl userDao = (UserDaoImpl) applicationContext.getBean("userDao");
         User user = new User();
         user.setId(2);
         user.setName("Tim");
         user.setAge(26);
         int num = userDao.addUser(user);
         if(num>0){
             System.out.println("成功修改"+num+"个用户");
         }else {
             System.out.println("修改用户信息失败！");
         }
     }
     @Test
     public void deleteTest(){
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
         UserDaoImpl userDao = (UserDaoImpl) applicationContext.getBean("userDao");
         int num = userDao.deleteUser(2);
         if(num>0){
             System.out.println("成功删除"+num+"个用户");
         }else {
             System.out.println("删除用户操作失败！");
         }
     }
     @Test
     public void query(){
         ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
         UserDaoImpl userDao = (UserDaoImpl) applicationContext.getBean("userDao");
         userDao.query();
     }
 }