spring学习笔记5
JdbcTemplate(概念和准备)
1、什么是JdbcTemplate
(1)Spring框架对JDBC进行封装,使用JdbcTemplate方便实现对数据库的操作
jabcTemplate操作数据库案例操作
(1)引入相应jar包
(2)在spring配置文件中配置数据库连接池
<!-- 数据库连接池 --> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close"> <property name="url" value="jdbc:mysql:///user_db?characterEncoding=UTF-8" /> <property name="username" value="root" /> <property name="password" value="root" /> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> </bean>
(3)配置JdbcTemplate对象,注入DataSource
<!-- JdbcTemplate对象 --> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <!--注入dataSource--> <property name="dataSource" ref="dataSource"></property> </bean>
(4)创建service类,创建dao类,在dao注入jdbcTemplate对象
*配置文件
<!--开启组件扫描--> <context:component-scan base-package="com.atguigu"></context:component-scan>
*Service
@Service public class BookService { //注入dao @Autowired private BookDao bookDao; }
*Dao
@Repository public class BookDaoImpl implements BookDao{ //注入jdbcTemplate @Autowired private JdbcTemplate jdbcTemplate; }
对应数据库实体
public class Book { private String userId; private String username; private String uStatus; public String getUserId() { return userId; } public void setUserId(String userId) { this.userId = userId; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getuStatus() { return uStatus; } public void setuStatus(String uStatus) { this.uStatus = uStatus; } @Override public String toString() { return "Book{" + "userId='" + userId + '\'' + ", username='" + username + '\'' + ", uStatus='" + uStatus + '\'' + '}'; } }
编写dao层方法
//添加方法 @Override public void add(Book book) { //1.创建sql语句 String sql = "insert into t_book values(?,?,?)"; String[] orgs = {book.getUserId(),book.getUsername(),book.getuStatus()}; int add = jdbcTemplate.update(sql,orgs); System.out.println(add); }
Service层
public void addBook(Book book){ bookDao.add(book); }
测试代码
@Test public void testJdbcTemplate(){ ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml"); BookService bookService = context.getBean("bookService",BookService.class); Book book = new Book(); book.setUserId("4"); book.setUsername("javadoc"); book.setuStatus("b"); //添加 bookService.addBook(book); }
修改dao层方法
@Override public void update(Book book) { String sql = "update t_book set username=?,ustatus=? where user_id=?"; String[] orgs = {book.getUsername(),book.getuStatus(),book.getUserId()}; int update = jdbcTemplate.update(sql,orgs); System.out.println(update); }
删除dao层方法
@Override public void delete(String id) { String sql = "delete from t_book where user_id=?"; String[] orgs = {id}; int delete = jdbcTemplate.update(sql,orgs); System.out.println(delete); }
查询
*查询返回某个值
//查询返回一个值 @Override public int findCount() { String sql = "select count(*) from t_book"; Integer count = jdbcTemplate.queryForObject(sql, Integer.class); return count; }
*查询寻返回对象
//查询返回对象 @Override public Book findById(String id) { String sql = "select * from t_book where user_id=?"; //调用方法 Book book = jdbcTemplate.queryForObject(sql,new BeanPropertyRowMapper<Book>(Book.class),id); return book; }
*查询返回集合
//查询返回集合 @Override public List<Book> list() { String sql = "select * from t_book"; //调用方法 List<Book> bookList = jdbcTemplate.query(sql,new BeanPropertyRowMapper<Book>(Book.class)); return bookList; }
批量添加
@Override public void batchAddBook(List<Object[]> batchArgs) { String sql = "insert into t_book values(?,?,?)"; int[] ints = jdbcTemplate.batchUpdate(sql,batchArgs); System.out.println(Arrays.toString(ints)); }
List<Object[]> batchArgs = new ArrayList<>(); Object[] o1 = {"31","java","a1"}; Object[] o2 = {"41","java","a1"}; Object[] o3 = {"51","java","a1"}; batchArgs.add(o1); batchArgs.add(o2); batchArgs.add(o3); bookService.batchAddBook( batchArgs);
批量修改
List<Object[]> batchArgs = new ArrayList<>(); Object[] o1 = {"java","a","3"}; Object[] o2 = {"c++","b","4"}; Object[] o3 = {"mysql","c","5"}; batchArgs.add(o1); batchArgs.add(o2); batchArgs.add(o3); bookService.batchUpdateBook( batchArgs);
@Override public void batchUpdateBook(List<Object[]> batchArgs) { String sql = "update t_book set username=?,ustatus=? where user_id=?"; int[] ints = jdbcTemplate.batchUpdate(sql,batchArgs); System.out.println(Arrays.toString(ints)); }
批量删除
List<Object[]> batchArgs = new ArrayList<>(); Object[] o1 = {"3"}; Object[] o2 = {"4"}; batchArgs.add(o1); batchArgs.add(o2); bookService.batchDeleteBook(batchArgs);
@Override public void batchDeleteBook(List<Object[]> batchArgs) { String sql = "delete from t_book where user_id=?"; int[] ints = jdbcTemplate.batchUpdate(sql,batchArgs); System.out.println(Arrays.toString(ints));
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