Spring JDBC实现查询

1 db.properties

 jdbc.user=root
 jdbc.password=920614
 jdbc.driverClass=com.mysql.jdbc.Driver
 jdbc.jdbcUrl=jdbc:mysql:///spring?useUnicode=true&characterEncoding=utf-8

 jdbc.initPoolSize=5
 jdbc.maxPoolSize=10

2 applicationContext.xml

 <?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:aop="http://www.springframework.org/schema/aop"
     xmlns:c="http://www.springframework.org/schema/c"
     xmlns:context="http://www.springframework.org/schema/context"
     xmlns:jdbc="http://www.springframework.org/schema/jdbc"
     xmlns:p="http://www.springframework.org/schema/p"
     xmlns:tx="http://www.springframework.org/schema/tx"
     xmlns:util="http://www.springframework.org/schema/util"
     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
         http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd
         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
         http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

     <context:component-scan base-package="com.spring.jdbc"></context:component-scan>
     <!-- 导入资源文件 -->
     <context:property-placeholder location="classpath:db.properties"/>
     <!-- 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>

     <!-- 配置 NamedParameterJdbcTemplate,
         该对象可以使用具名参数, 其没有无参数的构造器, 所以必须为其构造器指定参数 -->
     <bean id="namedParameterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
         <constructor-arg ref="dataSource"></constructor-arg>
     </bean>

     <!-- 配置事务管理器 -->
     <bean id="transactionManager"
           class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
           <property name="dataSource" ref="dataSource"></property>
     </bean>

     <!-- 启用事务注解 -->
     <tx:annotation-driven transaction-manager="transactionManager"/>

 </beans>

3 com.spring.jdbc

实体类

 package com.spring.jdbc;

 public class Employee {
     private int id;
     private String lastName;
     private String email;

     private int deptId;

     public int getDeptId() {
         return deptId;
     }
     public void setDeptId(int deptId) {
         this.deptId = deptId;
     }
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getLastName() {
         return lastName;
     }
     public void setLastName(String lastName) {
         this.lastName = lastName;
     }
     public String getEmail() {
         return email;
     }
     public void setEmail(String email) {
         this.email = email;
     }
     @Override
     public String toString() {
         return "Employee [id=" + id + ", lastName=" + lastName + ", email="
                 + email + ", deptId=" + deptId + "]";
     }

 }

EmployeeDao.java

 package com.spring.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 EmployeeDao {

     @Autowired
     private JdbcTemplate jdbcTemplate;

     public Employee get(int id){
         String sql="SELECT id,last_name lastName,email,dept_id FROM employees WHERE id=?";
         RowMapper<Employee> rowMapper=new BeanPropertyRowMapper<>(Employee.class);
         Employee employee=jdbcTemplate.queryForObject(sql, rowMapper,id);

         return employee;

     }
 }

 package com.spring.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.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;

 public class JdbcTest {

     private ApplicationContext ctx=null;
     private JdbcTemplate jdbcTemplate=null;
     private EmployeeDao employeeDao ;
     private DepartmentDao departmentDao ;
     private NamedParameterJdbcTemplate namedParameterJdbcTemplate=null;
     {
         ctx=new ClassPathXmlApplicationContext("beans-dataSource.xml");
         jdbcTemplate =(JdbcTemplate) ctx.getBean("jdbcTemplate");
         employeeDao = ctx.getBean(EmployeeDao.class);
         departmentDao = ctx.getBean(DepartmentDao.class);
         namedParameterJdbcTemplate=(NamedParameterJdbcTemplate) ctx.getBean("namedParameterJdbcTemplate");

     }

     /**
      * 使用具名参数时, 可以使用 update(String sql, SqlParameterSource paramSource) 方法进行更新操作
      * 1. SQL 语句中的参数名和类的属性一致!
      * 2. 使用 SqlParameterSource 的 BeanPropertySqlParameterSource 实现类作为参数.
      */
     @Test
     public void testNamedParameterJdbcTemplate2(){
         String sql="INSERT INTO employees(last_name,email,dept_id) VALUES(:lastName,:email,:deptId)";
         Employee employee=new Employee();
         employee.setLastName("LKQ");
         employee.setEmail("lkq@qq.com");
         employee.setDeptId(2);

         SqlParameterSource  sqlParameterSource =new  BeanPropertySqlParameterSource(employee);
         namedParameterJdbcTemplate.update(sql, sqlParameterSource);

     }
     /**
      * 可以为参数起名字.
      * 1. 好处: 若有多个参数, 则不用再去对应位置, 直接对应参数名, 便于维护
      * 2. 缺点: 较为麻烦.
      */
     @Test
     public void testNamedParameterJdbcTemplate(){
         String sql="INSERT INTO employees(last_name,email,dept_id) VALUES(:name,:email,:deptid)";
         Map<String,Object> paramMap=new HashMap<>();
         paramMap.put("name", "XJP");
         paramMap.put("email", "xjp@qq.com");
         paramMap.put("deptid",001);

         namedParameterJdbcTemplate.update(sql, paramMap);
     }

     @Test
     public void testDepartmentDao(){
         System.out.println(departmentDao.get(2));
     }
     @Test
     public void testEmployeeDao(){
         System.out.println(employeeDao.get(2));
     }

     /**
      *  从数据库中获取记录对象集合
      */
     @Test
     public void testQueryForList(){
         String sql="SELECT id,last_name lastName,email,dept_id FROM employees WHERE id>?";
         RowMapper<Employee> rowMapper=new BeanPropertyRowMapper<>(Employee.class);
         List<Employee> employees=jdbcTemplate.query(sql, rowMapper,8);

         System.out.println(employees);
     }

     /**
      *  从数据库中获取单个列的值，统计查询
      */
     @Test
     public void testQueryForObject2(){
         String sql="SELECT count(id) FROM employees";
         long count=jdbcTemplate.queryForObject(sql, Long.class);
         System.out.println(count);
     }

     /**
      *  从数据库中获取一条记录, 实际得到对应的一个对象
      */
     @Test
     public void testQueryForObject(){
         String sql="SELECT id,last_name lastName,email,dept_id FROM employees WHERE id=?";
         RowMapper<Employee> rowMapper=new BeanPropertyRowMapper<>(Employee.class);
         Employee employee=jdbcTemplate.queryForObject(sql, rowMapper,2);
         System.out.println(employee);
     }

     /**
      * 执行批量更新: 批量的 INSERT, UPDATE, DELETE
      * 最后一个参数是 Object[] 的 List 类型: 因为修改一条记录需要一个 Object 的数组, 那么多条不就需要多个 Object 的数组吗
      */
     @Test
     public void testBatchUpdate(){
         String sql="INSERT INTO employees(last_name,email,dept_id) VALUES(?,?,?)";

         List<Object[]> batchArgs=new ArrayList<>();
         batchArgs.add(new Object[]{"AA", "aa@atguigu.com", 1});
         batchArgs.add(new Object[]{"BB", "bb@atguigu.com", 2});
         batchArgs.add(new Object[]{"CC", "cc@atguigu.com", 3});
         batchArgs.add(new Object[]{"DD", "dd@atguigu.com", 3});
         batchArgs.add(new Object[]{"EE", "ee@atguigu.com", 2});

         jdbcTemplate.batchUpdate(sql, batchArgs);
     }
     /**
      * 执行 INSERT, UPDATE, DELETE
      */
     @Test
     public void testUpdate(){
         String sql="UPDATE employees SET last_name = ? WHERE id=?";
         jdbcTemplate.update(sql,"王根深",2);
     }
     @Test
     public void testDataSource() throws SQLException{
         DataSource dataSource =(DataSource) ctx.getBean("dataSource");
         System.out.println(dataSource.getConnection());
     }
 }