spring(4)——持久层封装

未分类

1. 持久层访问方式

2. JDBC

3. JDBCTemplete

3.1 原始jdbcTemplete

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

   <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

   @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

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

   去掉dao层的bean,即如下配置

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

   编写测试类

   @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

   <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

   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

   <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

   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);
       }
   }

3. 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：

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

   实例化前注入

   @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

   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-jdbc</artifactId>
   </dependency>

2. 配置项

   <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

   <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>

2. 配置项

   <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

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

2. 配置项

   <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)

   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

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

   方式二：一个property对应一个文件

   <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

<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>