Spring学习笔记07-JdbcTemplate

摘要：这两天学了Spring中的JdbcTemplate和NamedParameterJdbcTemplate。

一、JdbcTemplate

1、常用方法

• execute方法：可以用于执行任何SQL语句，一般用于执行DDL语句；
• 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；
• query方法及queryForXXX方法：用于执行查询相关语句；
• call方法：用于执行存储过程、函数相关语句。

2、实例

①在数据库建表

 ②新建实体类

package com.jdbc;

public class Person {
    
    private int id;
    private String name;
    private String password;
    private School school;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public School getSchool() {
        return school;
    }
    public void setSchool(School school) {
        this.school = school;
    }
    @Override
    public String toString() {
        return "Person [id=" + id + ", name=" + name + ", password=" + password + ", school=" + school + "]";
    }
    

}

package com.jdbc;

public class School {
    
    private int id;
    private String school;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getSchool() {
        return school;
    }
    public void setSchool(String school) {
        this.school = school;
    }
    @Override
    public String toString() {
        return "School [id=" + id + ", school=" + school + "]";
    }
    

}

③配置xml文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
    <!-- 导入资源文件 -->
    <context:property-placeholder
        location="classpath:db" />
    <context:component-scan base-package="com.jdbc"></context:component-scan>
    <!-- 配置C3P0数据源 -->
    <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>
        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
    </bean>
    <!-- 配置spring的 JdbcTemplate -->
    <bean id="JdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
</beans>

④新建JUnit测试用例类JDBCTest.java并编写测试代码

package com.jdbc;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.junit.jupiter.api.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;


class JDBCTest {
    private ApplicationContext c = null;
    private JdbcTemplate jdbcTemplate;
    private Dao dao;
    {
        c = new ClassPathXmlApplicationContext("jdbc.xml");
        jdbcTemplate = (JdbcTemplate) c.getBean("JdbcTemplate");
        dao = c.getBean(Dao.class);
    }
    
    @Test
    public void dao() {
        System.out.println(dao.get(58));
    }

    /*
     * 获取单个列的值，或统计查询
     */
    @Test
    public void huoqu1() {
        String sql ="select count(id) from m1";
        long count =jdbcTemplate.queryForObject(sql, long.class);
        System.out.println(count);
    }
    
    /*
     * 查到实体类集合,不调用queryforlist
     */
    @Test
    public void list() {
        String sql="select id, name, password from m1 where id > ?";
        RowMapper<Person> rowMapper=new BeanPropertyRowMapper<>(Person.class);
        List<Person> persons=jdbcTemplate.query(sql, rowMapper,59);
        System.out.println(persons);
    }

    /*
     *从数据库中获取一条记录，实际得到对应的一个对象
          注意不是调用 queryForObject(String sql，Class<Employee> requiredType，Object...args)方法！
          而需要调用queryForObject(String sql,RowMapper<Employee> rowMapper,Object...args)
      1.其中的 RowMapper 指定如何去映射结果集的行，常用的实现类为 BeanPropertyRowMapper
      2.使用 SQL 中列的别名完成列名和类的属性名的映射.例如last_name lastName
     */
    @Test
    public void huoqu() {
        String sql="select id, name, password from m1 where id = ?";
        RowMapper<Person> rowMapper=new BeanPropertyRowMapper<>(Person.class);
        Person person = jdbcTemplate.queryForObject(sql, rowMapper,56);
        System.out.println(person);
    }
    

    /*
     * 批量更新
     */

    @Test
    public void batchUpdateTest() {
        String sql="insert into m1(name,password) values(?,?)";
        List<Object[]> batchArgs = new ArrayList<>();
        batchArgs.add(new Object[] {"A","123"});
        batchArgs.add(new Object[] {"B","123"});
        batchArgs.add(new Object[] {"C","123"});

        jdbcTemplate.batchUpdate(sql,batchArgs);
    }

    /*
     * 执行insert,update, delete
     */
    @Test
    public void updateTest() {
        String sql="update m1 set name= ? where id = ?";
        jdbcTemplate.update(sql, "mmm",1);
    }

    @Test
    public void testDataSource() throws SQLException {
        DataSource dataSource=c.getBean(DataSource.class);
        System.out.println(dataSource.getConnection());
    }

}

package com.jdbc;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

@Repository
public class Dao {
    
    @Autowired
    private JdbcTemplate jdbcTemplate;
    
    public Person get(int id) {
        String sql="select id, name, password from m1 where id = ?";
        RowMapper<Person> rowMapper=new BeanPropertyRowMapper<>(Person.class);
        Person persons=jdbcTemplate.queryForObject(sql, rowMapper,id);
        return persons;
    }

}

二、NamedParameterJdbcTemplate

1、简介

NamedParameterJdbcTemplate类是基于JdbcTemplate类，并对它进行了封装从而支持命名参数特性。

NamedParameterJdbcTemplate主要提供以下三类方法：execute方法、query及queryForXXX方法、update及batchUpdate方法。

2、实例

①基于实例一，在xml文件中新加配置

<!-- 配置NamedParameterJdbcTemplate,可以使用具名参数，没有无参数的构造器 -->
    <bean id="namedParameterJdbcTemplate"
        class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
        <constructor-arg ref="dataSource"></constructor-arg>
    </bean>

②在JDBCTest.java中新加测试方法

package com.jdbc;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.junit.jupiter.api.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;


class JDBCTest {
    private ApplicationContext c = null;
    private JdbcTemplate jdbcTemplate;
    private Dao dao;
    private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
    {
        c = new ClassPathXmlApplicationContext("jdbc.xml");
        jdbcTemplate = (JdbcTemplate) c.getBean("JdbcTemplate");
        dao = c.getBean(Dao.class);
        namedParameterJdbcTemplate=c.getBean(NamedParameterJdbcTemplate.class);
    }
    /*
     * 使用namedParameterJdbcTemplate插入数据
     */
    
    @Test
    public void test() {
        String sql="insert into m1(name,password) values(:name,:password)";
        Map<String, Object> pMap = new HashMap<>();
        pMap.put("name", "小莫");
        pMap.put("password", "123");
        namedParameterJdbcTemplate.update(sql, pMap);
//      不推荐使用
//        Person person = new Person();
//        person.setName("小莫");
//        person.setPassword("123");
//        SqlParameterSource parameterSource = new BeanPropertySqlParameterSource(person);
//        namedParameterJdbcTemplate.update(sql, parameterSource);
    }
    
    @Test
    public void dao() {
        System.out.println(dao.get(1));
    }

    /*
     * 获取单个列的值，或统计查询
     */
    @Test
    public void huoqu1() {
        String sql ="select count(id) from m1";
        long count =jdbcTemplate.queryForObject(sql, long.class);
        System.out.println(count);
    }
    
    /*
     * 查到实体类集合,不调用queryforlist
     */
    @Test
    public void list() {
        String sql="select id, name, password from m1 where id > ?";
        RowMapper<Person> rowMapper=new BeanPropertyRowMapper<>(Person.class);
        List<Person> persons=jdbcTemplate.query(sql, rowMapper,1);
        System.out.println(persons);
    }

    /*
     *从数据库中获取一条记录，实际得到对应的一个对象
          注意不是调用 queryForObject(String sql，Class<Employee> requiredType，Object...args)方法！
          而需要调用queryForObject(String sql,RowMapper<Employee> rowMapper,Object...args)
      1.其中的 RowMapper 指定如何去映射结果集的行，常用的实现类为 BeanPropertyRowMapper
      2.使用 SQL 中列的别名完成列名和类的属性名的映射.例如last_name lastName
     */
    @Test
    public void huoqu() {
        String sql="select id, name, password from m1 where id = ?";
        RowMapper<Person> rowMapper=new BeanPropertyRowMapper<>(Person.class);
        Person person = jdbcTemplate.queryForObject(sql, rowMapper,56);
        System.out.println(person);
    }
    

    /*
     * 批量更新
     */

    @Test
    public void batchUpdateTest() {
        String sql="insert into m1(name,password) values(?,?)";
        List<Object[]> batchArgs = new ArrayList<>();
        batchArgs.add(new Object[] {"A","123"});
        batchArgs.add(new Object[] {"B","123"});
        batchArgs.add(new Object[] {"C","123"});

        jdbcTemplate.batchUpdate(sql,batchArgs);
    }

    /*
     * 执行insert,update, delete
     */
    @Test
    public void updateTest() {
        String sql="update m1 set name= ? where id = ?";
        jdbcTemplate.update(sql, "mmm",1);
    }

    @Test
    public void testDataSource() throws SQLException {
        DataSource dataSource=c.getBean(DataSource.class);
        System.out.println(dataSource.getConnection());
    }

}