jdbcTemplate
JDBCTest.java(com.test.spring.jdbc.JDBCTest)
INSERT,UPDATE,DELETE
/**
* 执行 INSERT,UPDATE,DELETE
*/
@Test
public void testUpdate() {
String sql = "UPDATE tb_student SET name = ? WHERE id = ?";
jdbcTemplate.update(sql, "小兰", 3);
}
@Test
public void test() throws SQLException {
DataSource dataSource = ctx.getBean(DataSource.class);
System.out.println(dataSource.getConnection());
}
批量的 INSERT,UPDATE,DELETE
/**
* 执行批量跟新: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,那么多条就需要多个 Object 的数组
*/
@Test
public void testBatchUpdate() {
String sql = "INSERT INTO tb_student(snum, name, age, sex, class_id) VALUES(?,?,?,?,?)";
List<Object[]> batchArgs = new ArrayList<>();
batchArgs.add(new Object[]{2147483647, "AA", 20, "男", 1013});
batchArgs.add(new Object[]{2147483647, "BB", 21, "女", 1014});
batchArgs.add(new Object[]{2147483647, "CC", 22, "女", 1013});
jdbcTemplate.batchUpdate(sql, batchArgs);
}
获取一条记录
/**
* 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 Name name
* 3. 不支持级联属性,JdbcTemplate 到底是一个 JDBC 的小工具,而不是 ORM 框架
*/
@Test
public void testQueryForObject() {
String sql = "SELECT id, name, email FROM employees WHERE id = ?";
RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 1);
System.out.println(employee);
}
获取实体类的集合
/**
* 查到实体类的集合
* 注意调用的不是 queryForList 方法
*/
@Test
public void testQueryForList() {
String sql = "SELECT id, name, email FROM employees WHERE id > ?";
RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
List<Employee> employees = jdbcTemplate.query(sql, rowMapper, 3);
System.out.println(employees);
}
获取单个列的值
/**
* 获取单个列的值,或做统计查询
* 使用 queryForObject(String sql, Class<Long> requiredType)
*/
@Test
public void testQueryForObject2() {
String sql = "SELECT count(id) FROM employees";
long count = jdbcTemplate.queryForObject(sql, Long.class);
System.out.println(count);
}
源码
package com.test.spring.jdbc;
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 javax.sql.DataSource;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class JDBCTest {
private ApplicationContext ctx = null;
private JdbcTemplate jdbcTemplate;
{
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");
}
/**
* 获取单个列的值,或做统计查询
* 使用 queryForObject(String sql, Class<Long> requiredType)
*/
@Test
public void testQueryForObject2() {
String sql = "SELECT count(id) FROM employees";
long count = jdbcTemplate.queryForObject(sql, Long.class);
System.out.println(count);
}
/**
* 查到实体类的集合
* 注意调用的不是 queryForList 方法
*/
@Test
public void testQueryForList() {
String sql = "SELECT id, name, email FROM employees WHERE id > ?";
RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
List<Employee> employees = jdbcTemplate.query(sql, rowMapper, 3);
System.out.println(employees);
}
/**
* 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 Name name
* 3. 不支持级联属性,JdbcTemplate 到底是一个 JDBC 的小工具,而不是 ORM 框架
*/
@Test
public void testQueryForObject() {
String sql = "SELECT id, name, email FROM employees WHERE id = ?";
RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 1);
System.out.println(employee);
}
/**
* 执行批量跟新: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,那么多条就需要多个 Object 的数组
*/
@Test
public void testBatchUpdate() {
String sql = "INSERT INTO tb_student(snum, name, age, sex, class_id) VALUES(?,?,?,?,?)";
List<Object[]> batchArgs = new ArrayList<>();
batchArgs.add(new Object[]{2147483647, "AA", 20, "男", 1013});
batchArgs.add(new Object[]{2147483647, "BB", 21, "女", 1014});
batchArgs.add(new Object[]{2147483647, "CC", 22, "女", 1013});
jdbcTemplate.batchUpdate(sql, batchArgs);
}
/**
* 执行 INSERT,UPDATE,DELETE
*/
@Test
public void testUpdate() {
String sql = "UPDATE tb_student SET name = ? WHERE id = ?";
jdbcTemplate.update(sql, "小兰", 3);
}
@Test
public void test() throws SQLException {
DataSource dataSource = ctx.getBean(DataSource.class);
System.out.println(dataSource.getConnection());
}
}
其他文件
配置Bean-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: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.xsd">
<!-- 导入资源文件 -->
<context:property-placeholder location="db.properties"></context:property-placeholder>
<!-- 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="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
<property name="driverClass" value="${jdbc.driverClass}"></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>
SQL地址文件-db.properties.txt
jdbc.user=root
jdbc.password=123456
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
jdbc.initPoolSize=5
jdbc.maxPoolSize=10
Employee.java(com.test.spring.jdbc.Employee)
这里面用toString只是为了方便后面的输出打印
package com.test.spring.jdbc;
public class Employee {
private Integer id;
private String name;
private String email;
private Integer age;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Employee{" +
"id=" + id +
", name='" + name + '\'' +
", email='" + email + '\'' +
", age=" + age +
'}';
}
}
JdbcDaoSupport
不推荐使用 JdbcDaoSupport,而推荐直接使用 jdbcTemplate 作为 Dao 类的成员变量
DepartmentDao.java(com.test.spring.jdbc.DepartmentDao)
package com.test.spring.jdbc;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;
import javax.sql.DataSource;
@Repository
public class DepartmentDao extends JdbcDaoSupport {
@Autowired
public void setDataSource2(DataSource dataSource){
setDataSource(dataSource);
}
public Department get(Integer id){
String sql = "SELECT id, name FROM employees WHERE id = ?";
RowMapper<Department> rowMapper = new BeanPropertyRowMapper<>(Department.class);
return getJdbcTemplate().queryForObject(sql, rowMapper, id);
}
}
EmployeeDao.java(com.test.spring.jdbc.EmployeeDao)
package com.test.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(Integer id) {
String sql = "SELECT id, name, email FROM employees WHERE id = ?";
RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 1);
return employee;
}
}
JDBCTest.java(com.test.spring.jdbc.JDBCTest)
package com.test.spring.jdbc;
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 javax.sql.DataSource;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class JDBCTest {
private ApplicationContext ctx = null;
private EmployeeDao employeeDao;
private DepartmentDao departmentDao;
{
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
employeeDao = ctx.getBean(EmployeeDao.class);
departmentDao = ctx.getBean(DepartmentDao.class);
}
@Test
public void testDepartmentDao(){
System.out.println(departmentDao.get(1));
}
@Test
public void testEmployeeDao() {
System.out.println(employeeDao.get(1));
}
}
NamedParameterJdbcTemplate
JDBCTest.java(com.test.spring.jdbc.JDBCTest)
public class JDBCTest {
private ApplicationContext ctx = null;
private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
{
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
namedParameterJdbcTemplate = ctx.getBean(NamedParameterJdbcTemplate.class);
}
/**
* 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(name, email, age) VALUES (:name,:email,:age)";
Employee employee = new Employee();
employee.setName("ZZ");
employee.setEmail("zz@test.com");
employee.setAge(22);
SqlParameterSource paramSource = new BeanPropertySqlParameterSource(employee);
namedParameterJdbcTemplate.update(sql, paramSource);
}
/**
* 可以为参数起名字。
* 优点: 若有多个参数,则不用再去对应位置,直接对应参数名就可以了,方便维护
* 缺点: 较为麻烦。
*/
@Test
public void testNamedParameterJdbcTemplate() {
String sql = "INSERT INTO employees(name, email, age) VALUES (:name,:email,:age)";
Map<String, Object> paramMap = new HashMap<>();
paramMap.put("name", "GG");
paramMap.put("email", "GG@test.com");
paramMap.put("age", 23);
namedParameterJdbcTemplate.update(sql, paramMap);
}
}
applicationContext.xml
在Bean中加入以下代码即可
<!-- 配置 NamedParameterJdbcTemplate,该对象可以使用具名参数,其没有无参数的构造器,所有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>