Spring註解開發Junit、JdbcTemeplate學習
阿新 • • 發佈:2020-12-15
1、Spring註解開發
常用原始註解
- @Controller 在web層類上例項化Bean
- @Service 在service層類上例項化Bean
- @Repository 在dao層上例項化Bean
- @Component 在通用類上例項化Bean
- @Autowired 根據型別依賴注入
- @Qualifier 跟@Autowired一起使用,可根據名稱依賴注入
- @Resource 相當於@Autiwired和@Qualifier,根據名稱依賴注入
- @Value 注入普通屬性
- @Scope 標註Bean的作用範圍
- @PostConstruct Bean的初始化方法
- @PreDestroy Bean的銷燬方法
常用新註解
- @Configuration 指定Spirng的配置類
- @ComponentScan 指定Spring初始化容器時需要掃描的包
- @Bean 使用在方法上,將返回值儲存到Spring容器中
- @PropertySource 用於載入properties檔案
- @Import 用於匯入其它包
2、案例
使用註解進行開發時,需要在applicationContext.xml中配置元件掃描
<context:component-scan base-package="cn.guixinchn"></context:component-scan>
然後使用註解@Service、@Repository 標識需要Spring例項化的類
使用@Autowired、@Qualifier進行依賴注入
@Repository("userDao") public class UserDaoImpl implements UserDao { public void save() { System.out.println("save running...."); } } @Service("userServer") public class UserServerImpl implements UserServer { @Autowired @Qualifier("userDao") private UserDao userDao; public UserServerImpl(UserDao userDao) { this.userDao = userDao; } public void save() { userDao.save(); } }
使用註解充當配置檔案
@Configuration
@ComponentScan("cn.guixinchn")
@PropertySource("classpath:jdbc.properties")
public class SpringConfiguration {
@Value("${jdbc.driver}")
private String driver;
@Value("${jdbc.url}")
private String url;
@Value("${jdbc.username}")
private String username;
@Value("${jdbc.password}")
private String password;
@Bean(name="dataSource")
public DataSource getDataSource () throws PropertyVetoException {
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass(driver);
dataSource.setJdbcUrl(url);
dataSource.setUser(username);
dataSource.setPassword(password);
return dataSource;
}
}
測試
@Test
public void test4() throws SQLException {
//獲取註解配置類的上下文物件
ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringConfiguration.class);
//拿到資料來源
DataSource dataSource = (DataSource) applicationContext.getBean("dataSource");
//獲得連線物件
Connection connection = dataSource.getConnection();
System.out.println(connection);
connection.close();
}
3、Spring整合Junit
3.1、匯入spring整合Junit的座標
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.0.2.RELEASE</version>
</dpendency>
3.2、使用@Runwith註解替換原來的執行期、使用@ContextConfiguration指定配置檔案或配置類
3.3、使用@Autowired注入需要測試的物件、使用@Test建立測試方法進行測試
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfiguration.class)
public class JunitTest {
@Autowired
private UserServer userServer;
@Test
public void test(){
userServer.save();
}
}
4、Spring框架中JdbcTemeplate的使用
4.1匯入spring-jdbc和spring-tx座標
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.0.3.RELEASE</version>
</depe
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>5.0.3.RELEASE</version>
</dependency>
4.2建立資料庫表和實體
public class Student {
private String name;
private int age;
/*省略set個get方法,tostring方法*/
}
4.3讓Spirng容器產生JdbcTemplate物件,並獲取資料來源
<!--Spring容器載入properties檔案-->
<context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"></property>
<property name="jdbcUrl" value="${jdbc.url}"></property>
<property name="user" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"></property>
</bean>
4.4建立測試類執行資料庫操作
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateTest {
@Autowired
private JdbcTemplate jdbcTemplate;
@Test
public void test1(){
int i = jdbcTemplate.update("insert into student value (?, ?)", "張三", 18);
System.out.println(i);
}
}
4.5測試JdbcTemplate的查詢操作
JdbcTemplate模板裡面通過RowMapper的實現類BeanPropertyRowMapper,為我們封裝實體類
@Test
public void queryAllTest(){
List<Student> studentList = jdbcTemplate.query("select * from student", new BeanPropertyRowMapper<Student>(Student.class));
System.out.println(studentList);
}
@Test
public void queryOneTest(){
Student student = jdbcTemplate.queryForObject("select * from student where name = ?", new BeanPropertyRowMapper<Student>(Student.class), "張三");
System.out.println(student);
}
@Test
public void queryCountTest(){
Long num = jdbcTemplate.queryForObject("select count(*) from student", Long.class);
System.out.println(num);
}