1、JdbcTemplate

spring對數據庫的操作在jdbc上做了更深層次的封裝JdbcTemplate，處理了資源的建立和釋放(不需要我們管理連接了),我們只需要提供SQL語句(不需要我們設置參數了)和提取結果(查詢時候可以直接返回對應的實體類),使JDBC更加易於使用。它也可以使用spring的註入功能，將數據源註入JdbcTemplate，來實現操作數據庫。

2、JdbcTemplate常用方法

• update(更新數據)
• batchUpdate(批量更新數據)
• queryForObject(查詢單行數據或者單值數據)

• query(查詢多行數據)

  3、Spring中實現jdbcTemplate對數據庫操作(采用c3p0連接池)

  1、需要導入的jar包

• spring-jdbc-5.0.6.RELEASE.jar
• spring-tx-5.0.6.RELEASE.jar
• mysql-connector-java-5.0.7.jar

• c3p0-0.9.5.2.jar

  2、springxml配置

    <context:property-placeholder
            location="classpath:jdbc.properties" />
        <!-- 配置c3p0數據源 -->
        <bean id="dataSource"
            class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="user" value="${jdbc.user}"></property>
            <property name="password" value="${jdbc.password}"></property>
            <property name="driverClass" value="${jdbc.driverClass}"></property>
            <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        </bean>
  
        <!-- 將c3p0數據源註入jdbcTemplate -->
        <bean id="jdbcTemplate"
            class="org.springframework.jdbc.core.JdbcTemplate">
            <property name="dataSource" ref="dataSource"></property>
        </bean>
   
  

  3、User實體類

    public class User {
  
        private int id;
        private String username;
        private String password;
  
        public User() {
            super();
        }
  
        public int getId() {
            return id;
        }
  
        public void setId(int id) {
            this.id = id;
        }
  
        public String getUsername() {
            return username;
        }
  
        public void setUsername(String username) {
            this.username = username;
        }
  
        public String getPassword() {
            return password;
        }
  
        public void setPassword(String password) {
            this.password = password;
        }
  
        @Override
        public String toString() {
            return "User [id=" + id + ", username=" + username + ", password=" + password + "]";
        }
  
    }
   
  

  4、測試類

    public void testUserServiceImpl() {
            //獲取IOC容器
            ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");    
  
            //通過ApplicationContext對象的getBean方法來獲取對象實例
            //獲取數據連接模板JdbcTemplate
            JdbcTemplate jdbcTemplate = (JdbcTemplate) context.getBean("jdbcTemplate");
  
            //增加
            String sql1 = "insert into user(username,password) values(?,?)";
            System.out.println(jdbcTemplate.update(sql1, "user","user123"));
  
            //修改
            String sql2 = "update user set username = ? where id = 10000";
            System.out.println(jdbcTemplate.update(sql2, "adminadmin"));
  
            //查詢基本數據
            String sql3 = "select count(*) from user";
            System.out.println(jdbcTemplate.queryForObject(sql3, Integer.class));
  
            //查詢單條記錄
            String sql4 = "select * from user where id = 10000";
            RowMapper<User> rowMapper = new BeanPropertyRowMapper<>(User.class);
            User user = jdbcTemplate.queryForObject(sql4, rowMapper);
            System.out.println(user);
  
            //查詢多條記錄
            String sql5 = "select * from user";
            List<User> list = jdbcTemplate.query(sql5, rowMapper);
            for (User user2 : list) {
                System.out.println(user2);
            }
  
            //批量插入
            String sql6 = "insert into user(username,password) values(?,?)";
            List<Object[]> batchArgs=new ArrayList<Object[]>();
            batchArgs.add(new Object[]{"aaaa","aaa123"});
            batchArgs.add(new Object[]{"bbbb","bbb123"});
            batchArgs.add(new Object[]{"cccc","ccc123"});
            jdbcTemplate.batchUpdate(sql6, batchArgs);
        }

spring操作數據庫