Dao: public interface StudentDao { void list(); void delete(int id); } @Repository public class MyBatisStudentDao implements StudentDao { @Override public void list() { System.out.println("MyBatisStudentDao 打印学生列表"); } @Override public void delete(int id) { System.out.println("MyBatisStudentDao 学生"+id+"已删除"); } } @Repository public class MockStudentDao implements StudentDao { @Override public void list() { System.out.println("MockStudentDao 打印学生列表"); } @Override public void delete(int id) { System.out.println("MockStudentDao 学生"+id+"已删除"); } } Service: public interface StudentService { void list(); void delete(int id); } @Service public class StudentServiceImpl implements StudentService { public final StudentDao studentDao; @Autowired public StudentServiceImpl(@Qualifier("myBatisStudentDao") StudentDao studentDao) { this.studentDao = studentDao; } @Override public void list() { studentDao.list(); } @Override public void delete(int id) { studentDao.delete(id); } } 测试类: public class main { @Test public void test(){ ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml"); StudentService studentService = (StudentService) ctx.getBean(StudentServiceImpl.class); studentService.list(); studentService.delete(2); } } 如果要使用@Resource注解实现装配,该如何修改代码
时间: 2023-06-20 20:06:48 浏览: 63
如果要使用@Resource注解实现装配,可以将StudentServiceImpl类中的@Autowired注解替换为@Resource注解,并指定对应的bean名称,例如:
```
@Service
public class StudentServiceImpl implements StudentService {
public final StudentDao studentDao;
@Resource(name="myBatisStudentDao")
public StudentServiceImpl(StudentDao studentDao) {
this.studentDao = studentDao;
}
@Override
public void list() {
studentDao.list();
}
@Override
public void delete(int id) {
studentDao.delete(id);
}
}
```
这样,Spring会自动从容器中查找名为"myBatisStudentDao"的bean,并将其注入到StudentServiceImpl对象中的studentDao属性中。在测试类中,可以保持不变,仍然使用ApplicationContext来加载配置文件并获取bean。
相关问题
如果要使用@Resource注解实现装配,该如何修改代码package org.example; public interface StudentDao { void list(); void delete(int id); } package org.example; public interface StudentService { void list(); void delete(int id); } package org.example; import org.springframework.stereotype.Repository; @Repository("mockStudentDao") public class MockStudentDao implements StudentDao{ @Override public void list() { System.out.println("All students are listed in MockStudentDao."); } @Override public void delete(int id) { System.out.println("Student No."+id+"is deleted in MockStudentDao."); } } package org.example; import org.springframework.stereotype.Repository; @Repository("myBatisStudentDao") public class MyBatisStudentDao implements StudentDao{ @Override public void list() { System.out.println("All students are listed in MyBatisStudentDao."); } @Override public void delete(int id) { System.out.println("Student No."+id+"is deleted in MyBatisStudentDao."); } } package org.example; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Service; @Service("studentServiceImpl") public class StudentServiceImpl implements StudentService{ private final StudentDao studentDao; @Autowired public StudentServiceImpl(@Qualifier("myBatisStudentDao")StudentDao studentDao){ this.studentDao=studentDao; } @Override public void list() { this.studentDao.list(); } @Override public void delete(int id) { this.studentDao.delete(id); } } package org.example; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Main { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml"); StudentService studentService = (StudentService) ctx.getBean("studentServiceImpl"); studentService.list(); studentService.delete(10); } }如果要使用MockStudentDao
可以将StudentServiceImpl中的@Qualifier("myBatisStudentDao")修改为@Qualifier("mockStudentDao"),即:
@Service("studentServiceImpl")
public class StudentServiceImpl implements StudentService{
private final StudentDao studentDao;
@Autowired
public StudentServiceImpl(@Qualifier("mockStudentDao")StudentDao studentDao){
this.studentDao=studentDao;
}
@Override
public void list() {
this.studentDao.list();
}
@Override
public void delete(int id) {
this.studentDao.delete(id);
}
}
这样,Spring会将MockStudentDao注入到StudentServiceImpl中,从而实现装配。同时,在beans.xml中也需要将MockStudentDao的bean定义加入进去。
要求:假设通过StudentController、StudentService和StudentDao等类和接口完成学生的保存操作,请编程实现相关的接口和类,要求采用Spring框架技术中提供的控制反转和依赖注入的松耦合编程方法,使用基于Annotation的Bean装配方法来实现相关组件的生成,写出测试程序,运行查看其结果实验心得
好的,根据您的要求,我来为您解答这个问题。
首先,我们需要定义相关的接口和类,具体如下:
StudentController.java
```java
public interface StudentController {
void saveStudent(Student student);
}
```
StudentService.java
```java
public interface StudentService {
void saveStudent(Student student);
}
```
StudentDao.java
```java
public interface StudentDao {
void saveStudent(Student student);
}
```
Student.java
```java
public class Student {
private String name;
private int age;
// 省略getter和setter方法
}
```
接下来,我们需要实现这些接口和类。为了实现松耦合编程,我们需要使用Spring框架提供的控制反转和依赖注入的机制,具体如下:
StudentControllerImpl.java
```java
@Controller
public class StudentControllerImpl implements StudentController {
@Autowired
private StudentService studentService;
@Override
public void saveStudent(Student student) {
studentService.saveStudent(student);
}
}
```
StudentServiceImpl.java
```java
@Service
public class StudentServiceImpl implements StudentService {
@Autowired
private StudentDao studentDao;
@Override
public void saveStudent(Student student) {
studentDao.saveStudent(student);
}
}
```
StudentDaoImpl.java
```java
@Repository
public class StudentDaoImpl implements StudentDao {
@Override
public void saveStudent(Student student) {
// 实现保存学生信息的逻辑
}
}
```
在这些类中,我们使用了基于Annotation的Bean装配方法来实现相关组件的生成。具体来说,我们使用了@Controller、@Service和@Repository注解来分别表示控制器、服务和DAO层组件,然后使用@Autowired注解来进行依赖注入。
最后,我们需要编写测试程序来验证我们的代码是否正确。具体如下:
```java
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:spring.xml")
public class StudentControllerTest {
@Autowired
private StudentController studentController;
@Test
public void testSaveStudent() {
Student student = new Student();
student.setName("Tom");
student.setAge(18);
studentController.saveStudent(student);
}
}
```
在这个测试程序中,我们使用了Spring框架提供的测试工具类,然后使用@Autowired注解来进行依赖注入。在测试方法中,我们创建了一个学生对象,然后调用控制器的保存方法来保存学生信息。
通过运行测试程序,我们可以验证我们的代码是否正确。如果一切正常,我们应该能够看到保存学生信息的结果。
至于实验心得,我认为使用Spring框架可以很方便地实现松耦合编程,提高了代码的可维护性和可扩展性。同时,基于Annotation的Bean装配方法也让代码更加简洁和易于理解。
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