Spring入门学习（使用JdbcTemplate和JdbcDaoSupport&NamedParameterJdbcTemplate） 第十八节

其他 2019-01-12 16:02:33 阅读次数: 0
版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u011171125/article/details/86022386

Spring入门学习（使用JdbcTemplate和JdbcDaoSupport）

使用JdbcTemplate

  1. 导入必要的maven依赖
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>4.1.2.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.1.3.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
    <version>4.1.3.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-aop -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>4.1.3.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
    <version>4.1.3.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>4.1.3.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.6.8</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5.2</version>
</dependency>

<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.21</version>
</dependency>

<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>
  2. 简单配置连接mysql的数据库配置文件db.properties
    jdbc.user=root
jdbc.password=zwf1233
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql://localhost:3306/springstudy3

jdbc.initPoolSize=5
jdbc.maxPoolSize=10
  3. 创建applicationContext.xml配置文件，添加包扫描，导入db配置文件并配置c3p0数据源，最后添加Spring的JdbcTemplete。
    <?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-4.1.xsd">

	<context:component-scan base-package="com.fafa.spring.*"></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="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JdbcTemplete -->
	<bean id="jdbcTemplete" class="org.springframework.jdbc.core.JdbcTemplate">
		<property name="dataSource" ref="dataSource"></property>
	</bean>
	
</beans>
  4. 创建mysql数据库中的相关表及数据：
    /*Table structure for table `departments` */

DROP TABLE IF EXISTS `departments`;

CREATE TABLE `departments` (
  `ID` tinyint(10) NOT NULL AUTO_INCREMENT,
  `DEPT_NAME` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

/*Data for the table `departments` */

insert  into `departments`(`ID`,`DEPT_NAME`) values (1,'财务部'),(2,'开发部'),(3,'公关部');

/*Table structure for table `employees` */

DROP TABLE IF EXISTS `employees`;

CREATE TABLE `employees` (
  `ID` tinyint(10) NOT NULL AUTO_INCREMENT,
  `LAST_NAME` varchar(20) DEFAULT NULL,
  `EMAIL` varchar(50) DEFAULT NULL,
  `DEPT_ID` tinyint(10) DEFAULT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;

/*Data for the table `employees` */

insert  into `employees`(`ID`,`LAST_NAME`,`EMAIL`,`DEPT_ID`) values (1,'Tom','[email protected]',1),(2,'Jerry','[email protected]',2),(3,'Mike','[email protected]',3),(4,'Rose','[email protected]',3),(5,'fafa','[email protected]',2);
  5. 创建JDBCTest类：
    public class JDBCTest {

	private ApplicationContext ctx = null;
	private JdbcTemplate jdbcTemplate;
	
	{
		ctx = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplete");
	}

	@Test
	public void testDataSource() throws SQLException {
		DataSource dataSource = (DataSource) ctx.getBean("dataSource");
		System.out.println(dataSource.getConnection());
	}
	
}
    测试结果：
    com.mchange.v2.c3p0.impl.NewProxyConnection@1113fd74 [wrapping: com.mysql.jdbc.JDBC4Connection@3764d36e]
  6. 使用jdbcTemplete更新数据：
    /**
 * 执行insert,update,delete
 */
@Test
public void testUpdate() {
	String sql = "UPDATE employees SET last_name=? where id=?";
	jdbcTemplate.update(sql, "Jack", 5);
}
    测试结果（前后结果对比）：
    在这里插入图片描述 在这里插入图片描述
  7. 执行批量更新
    /**
 * 执行批量更新:批量insert，update，delete
 * 后面最后一个参数是Object[]的list类型：因为修改一条记录需要一个Object数组，多条就需要多个Object数组
 */
@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","[email protected]",1});
	batchArgs.add(new Object[]{"BB","[email protected]",2});
	batchArgs.add(new Object[]{"CC","[email protected]",3});
	batchArgs.add(new Object[]{"DD","[email protected]",3});
	batchArgs.add(new Object[]{"EE","[email protected]",2});
	jdbcTemplate.batchUpdate(sql, batchArgs);
}
    执行结果：
    在这里插入图片描述
  8. 查询结果为对象：
    新建Employee类
    public class Employee {

	private Integer id;
	private String lastName;
	private String email;
	
	private Integer deptId;

	public Integer getId() {
		return id;
	}

	public void setId(Integer 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;
	}

	public Integer getDeptId() {
		return deptId;
	}

	public void setDeptId(Integer deptId) {
		this.deptId = deptId;
	}

	@Override
	public String toString() {
		return "Employee [id=" + id + ", lastName=" + lastName + ", email="
				+ email + ", deptId=" + deptId + "]";
	}
	
}
    测试方法：
    /**
 * 从数据库中获取一条记录，实际得到一个对应的对象
 *
  注意不是调用queryForObject(String sql, Class<Employee> requiredType, Object... args) 这个方法
 * 而需要调用queryForObject(String sql, RowMapper<Employee> rowMapper, Object... args) 
 * 1. 其中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中的别名完成列名和属性名的映射，列入last_name lastName
 * 3. 不支持级联属性，JdbcTemplete 到底是一个JDBC的小工具而不是ORM框架
 */
@Test
public void testQueryForObject() {
	String sql = "SELECT id, last_name, email, dept_id as \"department.id\" FROM employees WHERE id=?";
	RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
	Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 5);
	System.out.println(employee);
}
    查询结果：
    Employee [id=5, lastName=Jack, [email protected], deptId=null]
  9. 查询实体类集合：
    /**
 * 查询实体类集合
 * 注意调用的不是queryForList方法
 */
@Test
public void testQueryForList(){
	String sql = "SELECT id, last_name, email FROM employees WHERE id>?";
	RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
	List<Employee> employee = jdbcTemplate.query(sql, rowMapper, 5);
	System.out.println(employee);
}
    测试结果：
    [Employee [id=6, lastName=AA, [email protected], deptId=null], Employee [id=7, lastName=BB, [email protected], deptId=null], Employee [id=8, lastName=CC, [email protected], deptId=null], Employee [id=9, lastName=DD, [email protected], deptId=null], Employee [id=10, lastName=EE, [email protected], deptId=null]]
  10. 获取单列值或作统计：
    /**
 * 获取单个列的值，或作统计查询
 * 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);
}
    测试结果：10
  11. 使用Dao获取数据，新建EmployeeDao类：
    @Repository
public class EmployeeDao {

	@Autowired
	private JdbcTemplate jdbcTemplate;
	
	public Employee get(Integer id){
		String sql = "SELECT id, last_name, email FROM employees WHERE id=?";
		RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
		Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 5);
		return employee;
	}
}
    测试类：
    public class JDBCTest {

	private ApplicationContext ctx = null;
	private EmployeeDao employeeDao;
	
	{
		ctx = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		employeeDao = ctx.getBean(EmployeeDao.class);
	}

	@Test
	public void testEmployeeDao(){
		System.out.println(employeeDao.get(1));
	}
}
    测试结果：
    Employee [id=5, lastName=Jack, [email protected], deptId=null]

使用JdbcDaoSupport

  1. 新建Department类和DepartmentDao类
    不推荐使用JdbcDaoSupport这种方式，而推荐直接使用JdbcTemplate作为DAO类成员变量
    public class Department {

	private Integer id;
	private String name;
	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;
	}
	@Override
	public String toString() {
		return "Department [id=" + id + ", name=" + name + "]";
	}
}

/**
 * 不推荐使用JdbcDaoSupport这种方式，而推荐直接使用JdbcTemplate作为DAO类成员变量
 * @author Stark
 *
 */
@Repository
public class DepartmentDao extends JdbcDaoSupport {
	
	@Autowired
	public void setDataSource2(DataSource dataSource){
		setDataSource(dataSource);
	}
	
	public Department get(Integer id) {
		String sql = "SELECT id, dept_name name FROM departments WHERE id = ?";
		RowMapper<Department> rowMapper = new BeanPropertyRowMapper<>(Department.class);
		Department department = getJdbcTemplate().queryForObject(sql, rowMapper,1);
		return department;
	}
}

public class JDBCTest {

		private ApplicationContext ctx = null;
		private DepartmentDao departmentDao;
		
		{
			ctx = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
			departmentDao = ctx.getBean(DepartmentDao.class);
		}

		@Test
	public void testDepartmentDao() {
		System.out.println(departmentDao.get(1));
	}
}
    测试结果：
    Department [id=1, name=财务部]

使用 NamedParameterJdbcTemplate

  1. 在xml配置文件中增加NamedParameterJdbcTemplate：
    <!-- 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"/>
</bean>
  2. 测试类：
    public class JDBCTest {

	private ApplicationContext ctx = null;
	private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
	
	{
		ctx = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		namedParameterJdbcTemplate = ctx.getBean(NamedParameterJdbcTemplate.class);
	}

	/**
	 * 可以为参数起名称。
	 * 1. 好处：若有多个参数，则不用再去对应位置了，而直接对应参数名，增强了可维护性；
	 * 2. 缺点：较为麻烦。
	 */
	@Test
	public void testNamedParameterJdbcTemplate() {
		String sql = "INSERT INTO employees(last_name,email,dept_id)VALUES(:ln,:email,:deptid)";
		
		Map<String, Object> paramMap = new HashMap<String, Object>();
		paramMap.put("ln", "FF");
		paramMap.put("email", "[email protected]");
		paramMap.put("deptid", 2);
		namedParameterJdbcTemplate.update(sql, paramMap);
	}
	
	/**
	 * 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("XYZ");
		employee.setEmail("[email protected]");
		employee.setDeptId(3);
		SqlParameterSource paramSource = new BeanPropertySqlParameterSource(employee);
		namedParameterJdbcTemplate.update(sql, paramSource);
	}
}
    测试结果：
    在这里插入图片描述在这里插入图片描述

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