spring(4)——持久层封装

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这边博客介绍了持久层的集中封装方式。

1. 持久层访问方式

数据访问方式

2. JDBC

3. JDBCTemplete

3.1 原始jdbcTemplete

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DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/springdb");
dataSource.setUsername("root");
dataSource.setPassword("***********");

JdbcTemplate template = new JdbcTemplate(dataSource);
template.execute("insert into student values(1,'张三',23)");

3.2 Spring开发jdbcTemplete

  1. 设置Bean

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    <bean id="dao" class="com.topvision.daotest.Dao">
    	<property name="jdbcTemplate" ref="jdbcTemplate" />
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    	<property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    	<property name="driverClassName" value="com.mysql.jdbc.Driver" />
    	<property name="url" value="jdbc:mysql://localhost:3306/springdb" />
    	<property name="username" value="root" />
    	<property name="password" value="xiaoyue*AZ2V65" />
    </bean>

  2. 编写dao层测试类

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    @Test
    public void Demo1() {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("jdbcTemplete.xml");
        JdbcTemplate jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");
        jdbcTemplate.execute("insert into student values(5,'23423',24)");
    }

    或者注解式

    开启注解扫描

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    <context:component-scan base-package="com.topvision.daotest"/>

    去掉dao层的bean,即如下配置

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    <bean id="dao" class="com.topvision.daotest.Dao">
    	<property name="jdbcTemplate" ref="jdbcTemplate" />
    </bean>
编写测试类

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    @RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations="classpath:jdbcTemplete.xml")
public class Dao {
	
    	@Autowired
    	private JdbcTemplate jdbcTemplate;
    
    	public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
    		this.jdbcTemplate = jdbcTemplate;
    	}
    	@Test
    	public void Demo2() {
    		jdbcTemplate.execute("insert into student values(8,'王五',25)");
    	}
	}

3. jdbcDaoSupport

JdbcDaoSupport是JDBC数据访问对象的超类，其实它使用的还是jdbcTemplete，不过需要DI依赖注入dataSource或者jdbcTemplete.

3.1 xml方式

  1. xml配置文件

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    <bean id="jdbcDaoSupportTest" class="com.topvision.daotest.JDBCDaoSupportTest">
    		<bean id="jdbcDaoSupportTest" class="com.topvision.daotest.JDBCDaoSupportTest">
    		<!-- 必须为继承JdbcDaoSupport的类注入JdbcTemplate，变量名为jdbcTemplate -->
    		<!-- <property name="jdbcTemplate" ref="jdbcTemplate"/> -->
    		<!-- 还可以注入DataSource对象，由JdbcDaoSupport自动创建JdbcTemplate对象 -->
    		<property name="dataSource" ref="dataSource" />
    	</bean>
    	
        <bean id="dataSource"
        	class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        	<property name="driverClassName" value="com.mysql.jdbc.Driver" />
        	<property name="url" value="jdbc:mysql://localhost:3306/springdb" />
        	<property name="username" value="root" />
        	<property name="password" value="*****" />
        </bean>

  2. 测试类

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     public class JDBCDaoSupportTest extends JdbcDaoSupport{
    	
    	private static ClassPathXmlApplicationContext ctx;

    	@Test
    	public void Demo2() {
    		ctx = new ClassPathXmlApplicationContext("jdbcDaoSupport.xml");
    		JDBCDaoSupportTest bean = (JDBCDaoSupportTest) ctx.getBean("jdbcDaoSupportTest");
    		JdbcTemplate template = bean.getJdbcTemplate();
    		String sql = "select name from student where id = ?";
    		String name = template.queryForObject(sql, String.class,1);
    		System.out.println(name);
    	}
    }

3.2 注解方式

  1. xml配置

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     <bean id="dataSource"
    	class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    	<property name="driverClassName" value="com.mysql.jdbc.Driver" />
    	<property name="url" value="jdbc:mysql://localhost:3306/springdb" />
    	<property name="username" value="root" />
    	<property name="password" value="*****" />
    </bean>
  1. 测试类
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     public class JDBCDaoSupportTest extends JdbcDaoSupport{

        	@Autowired
        	private DataSource dataSource;
        	
        	@PostConstruct
        	private void init() {
        		setDataSource(dataSource);
        	}
        
        	@Test
        	public void Demo1() {
        		JdbcTemplate template = this.getJdbcTemplate();
        		String sql = "select name from student where id = ?";
        		String name = template.queryForObject(sql, String.class,1);
        		System.out.println(name);
        	}
    }

  1. 注入dataSource注意事项
    查看jdbcDaoSupport源码，可以注入dataSource或者注入jdbcTemplete
    注入方法有两种：

    构造方法中注入：

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    @Autowired
    UserVODaoImpl(DataSource dataSource) {
        setDataSource(dataSource);
    }

    实例化前注入

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    @Autowired
    private DataSource dataSource;

    @PostConstruct
    private void init() {
    	setDataSource(dataSource);
    }

4. Hibernate

5. Mybatis

6. DataSource

6.1 Spring内置DriverManagerDataSource

  1. 资源包

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       <dependency>
       	<groupId>org.springframework</groupId>
       	<artifactId>spring-jdbc</artifactId>
       </dependency>
       ```  
       
    2. 配置项

       ```xml
       <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
           <property name="driverClassName" value="com.mysql.jdbc.Driver" />
           <property name="url" value="jdbc:mysql://localhost:3306/springdb"/>
           <property name="username" value="root" />
           <property name="password" value="****" />
       </bean>

6.2 DBCP

  1. 资源包

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       <dependency>
           <groupId>org.apache.commons</groupId>
           <artifactId>com.springsource.org.apache.commons.dbcp</artifactId>
           <version>1.2.2.osgi</version>
       </dependency>
       <dependency>
           <groupId>org.apache.commons</groupId>
           <artifactId>com.springsource.org.apache.commons.pool</artifactId>
           <version>1.5.3</version>
       </dependency>
       ```  
       

    4. 配置项
       
       ```xml
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    	<property name="driverClassName" value="com.mysql.jdbc.Driver" />
    	<property name="url" value="jdbc:mysql://localhost:3306/springdb" />
    	<property name="username" value="root" />
    	<property name="password" value="*****" />
    </bean>

6.3 C3P0

  1. 资源包

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       <dependency>
    	<groupId>com.mchange.c3p0</groupId>
    	<artifactId>com.springsource.com.mchange.v2.c3p0</artifactId>
    	<version>0.9.1.2</version>
    </dependency>
       ```  
       

    6. 配置项
       
       ```xml
    <bean id="dataSource3" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    	<property name="driverClass" value="${driverClass}" />
    	<property name="jdbcUrl" value="${url}" />
    	<property name="user" value="${jdbc_username}" />
    	<property name="password" value="${password}" />
    </bean>

6.4 外部properties输入参数

  1. 编写properties文件(jdbc.properties)

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    driverClass=com.mysql.jdbc.Driver
    url=jdbc:mysql://localhost:3306/springdb
    jdbc_username=root
    password=*****

  2. 在spring配置文件中扫描properties

    方式一：可用*匹配加载多个

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    <context:property-placeholder location="classpath:jdbc.properties"/>

    方式二：一个property对应一个文件

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    <bean class="org.springframework.beans.factory.config.PropertyPlaceholdeConfigurer">
    	<property name="location" value="classpath:jdbc.properties" />
    	<property name="location" value="classpath:dsafgusd" />
    </bean>

  3. 用&{key}的方式引入

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<bean id="dataSource3" class="com.mchange.v2.c3p0.ComboPooledDataSource">
	<property name="driverClass" value="${driverClass}" />
	<property name="jdbcUrl" value="${url}" />
	<property name="user" value="${jdbc_username}" />
	<property name="password" value="${password}" />
</bean>
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