JDBCTemplat

1、JdbcTemplate介绍

为了使 JDBC 更加易于使用,Spring 在 JDBCAPI 上定义了一个抽象层, 以此建立一个JDBC存取框架，Spring Boot Spring Data-JPA。

作为 SpringJDBC 框架的核心, JDBC 模板的设计目的是为不同类型的JDBC操作提供模板方法. 每个模板方法都能控制整个过程,并允许覆盖过程中的特定任务。

通过这种方式,可以在尽可能保留灵活性的情况下,将数据库存取的工作量降到最低。

 

2、JdbcTemplate方法介绍

JdbcTemplate主要提供以下方法:

1、execute方法：可以用于执行任何SQL语句，一般用于执行DDL语句；

       Execute、executeQuery、executeUpdate

2、update方法及batchUpdate方法：update方法用于执行新增、修改、删除等语句；batchUpdate方法用于执行批处理相关语句 SQL SERVCER(GO SQL语句 GO) ；

3、query方法及queryForXXX方法：用于执行查询相关语句；

4、call方法：用于执行存储过程、函数相关语句。

一.配置式：

　　首先DAO层(以图书为例)：

package com.jdbc.dao;

import com.jdbc.entity.Book;
import java.util.List;

public interface IBookDao {
    //查询所有图书信息
    public List<Book> getBook();

}

package com.jdbc.dao.impl;

import com.jdbc.dao.IBookDao;
import com.jdbc.entity.Book;
import com.jdbc.entity.User;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;

import javax.annotation.Resource;
import java.util.List;

@Repository
public class IBookDaoImpl implements IBookDao {


    @Override
    public List<Book> getBook() {
        JdbcTemplate template = this.getJdbcTemplate();
        String sql="select * from book";
        List<Book> list = template.query(sql, new RowMapper<Book>() {
            @Override
            public Book mapRow(ResultSet rs, int rowNum) throws SQLException {
                Book book = new Book();
                book.setBid(rs.getString("bid"));
                book.setBname(rs.getString("bname"));
                book.setBauthor(rs.getString("bauthor"));
                book.setBprice(rs.getDouble("bprice"));
                return book;
            }
        });


        return list;
    }

　　Service层（同dao层方法一样）：

package com.jdbc.service;

import com.jdbc.entity.Book;
import com.jdbc.entity.User;

import java.util.List;

public interface IBookService {
    public List<Book> getBook();
}

package com.jdbc.service.impl;

import com.jdbc.dao.IBookDao;
import com.jdbc.dao.impl.IBookDaoImpl;
import com.jdbc.entity.Book;
import com.jdbc.service.IBookService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service("bookService")
public class IBookServiceImpl implements IBookService {
    @Resource
    private IBookDao bookDao;

    @Override
    public List<Book> getBook() {
        return bookDao.getBook();
    }

    public IBookDao getBookDao() {
        return bookDao;
    }

    public void setBookDao(IBookDao bookDao) {
        this.bookDao = bookDao;
    }
}

　　然后测试：

import com.jdbc.entity.Book;
import com.jdbc.entity.User;
import com.jdbc.service.IBookService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

public class IBookJdbcTemplateTest {

    /**
     *
     * 查询所有图书
     *
     */
   @Test
   public void bookTest(){
       ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
       IBookService bookService=(IBookService) ctx.getBean("bookService");

       List<Book> book = bookService.getBook();
       for (Book items:book){
           System.out.println("书籍编号："+items.getBid());
           System.out.println("	名称："+items.getBname());
           System.out.println("	作者："+items.getBauthor());
           System.out.println("	价格："+items.getBprice());
           System.out.println("================");

       }
   }

二.注解

　　

　　以用户为例（我这里用的依旧是Book的接口和类）：

　　DAO层（增删改查都在里边）：

package com.jdbc.dao;

import com.jdbc.entity.Book;
import com.jdbc.entity.User;

import java.util.List;

public interface IBookDao {

　　

//查询所有图书信息
public List<Book> getBook();

//查询所有用户 public List<User> getAllUser(); //添加用户 public int addUser(User user); //删除用户 public int deleteUser(int id); //修改用户 public int setUser(String name,int id); }

package com.jdbc.dao.impl;

import com.jdbc.dao.IBookDao;
import com.jdbc.entity.Book;
import com.jdbc.entity.User;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;

import javax.annotation.Resource;
import java.util.List;

@Repository
public class IBookDaoImpl implements IBookDao {


    @Resource
    private JdbcTemplate jdbcTemplate;
    @Override
    public List<Book> getBook() {
        //JdbcTemplate template = this.getJdbcTemplate();
        String sql="select * from book";
        /*List<Book> list = template.query(sql, new RowMapper<Book>() {
            @Override
            public Book mapRow(ResultSet rs, int rowNum) throws SQLException {
                Book book = new Book();
                book.setBid(rs.getString("bid"));
                book.setBname(rs.getString("bname"));
                book.setBauthor(rs.getString("bauthor"));
                book.setBprice(rs.getDouble("bprice"));
                return book;
            }
        });*/

        RowMapper<Book> rmapp=new BeanPropertyRowMapper<>(Book.class);
        List<Book> list = jdbcTemplate.query(sql, rmapp);

        return list;
    }

    @Override
    public List<User> getAllUser() {
        String sql="select * from user";
        RowMapper<User> umapper=new BeanPropertyRowMapper<>(User.class);
        List<User>list = jdbcTemplate.query(sql, umapper);
        return list;
    }

    @Override
    public int addUser(User user) {
        String sql="insert into user (uid,uname,upwd) values(?,?,?)";
        Object [] obj={user.getUid(),user.getUname(),user.getUpwd()};
        int count = jdbcTemplate.update(sql,obj);
        return count;
    }

    @Override
    public int deleteUser(int id) {
        String sql="delete from user where uid=?";
        int count = jdbcTemplate.update(sql, id);
        return count;
    }

    @Override
    public int setUser(String name,int id) {
        String sql="UPDATE `user` SET uname=? WHERE uid=?";
        int count = jdbcTemplate.update(sql, name, id);
        return count;
    }


}

　　Service层和前边一样这里就不拿出来了

　　然后是测试类：

import com.jdbc.entity.Book;
import com.jdbc.entity.User;
import com.jdbc.service.IBookService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

public class IBookJdbcTemplateTest {

    /**
     *
     * 查询所有图书
     *
     */
   @Test
   public void bookTest(){
       ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
       IBookService bookService=(IBookService) ctx.getBean("bookService");

       List<Book> book = bookService.getBook();
       for (Book items:book){
           System.out.println("书籍编号："+items.getBid());
           System.out.println("	名称："+items.getBname());
           System.out.println("	作者："+items.getBauthor());
           System.out.println("	价格："+items.getBprice());
           System.out.println("================");

       }
   }

    /**
     *
     * 查询所有用户
     */

   @Test
    public void UTest(){
       ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
       IBookService bookService=(IBookService) ctx.getBean("bookService");
       List<User> list=bookService.getAllUser();
       for (User us:list){
           System.out.println(us.getUname());
       }


   }

    /**
     *
     * 添加用户
     */
   @Test
    public void addTest(){
       ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
       IBookService bookService=(IBookService) ctx.getBean("bookService");
       User us=new User();
       us.setUid(4);
       us.setUname("hehe");
       us.setUpwd("8888");
       int count = bookService.addUser(us);

       System.out.println("成功！共"+count+"行受影响！");

   }

    /**
     *
     * 删除用户
     */
  @Test
  public void deleteTest(){
      ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
      IBookService bookService=(IBookService) ctx.getBean("bookService");
      int count = bookService.deleteUser(3);
      System.out.println("删除成功！	共"+count+"行受影响！");

  }

    /**
     *
     * 修改用户
     */

    @Test
    public void updateUserTest(){
        ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext_jdbcTemplate.xml");
        IBookService bookService=(IBookService) ctx.getBean("bookService");
        int count = bookService.setUser("dyuy", 2);
        System.out.println("修改成功！	共"+count+"行受影响！");

    }


}

执行结果就不再写出来了！