spring依赖注入之构造器形式注入

spring依赖注入之构造器方式注入
public class StudentDao implements IStudentDao { public void saveStudent() { System.out.println("成功保存一个学生信息"); }}

?

2. 服务层

public class StudentService implements IStudentService {   private IStudentDao studentDao;   private String id;   public StudentService(IStudentDao studentDao,String id){    this.studentDao = studentDao;    this.id = id;   } public void saveStudent() {  studentDao.saveStudent();  System.out.print(",ID为："+id); }}

?

3. spring配置

 <bean id="studentDao" type="com.wch.dao.IStudentDao" ref="studentDao" />      <constructor-arg index="1" value="123456" type="java.lang.String"></constructor-arg>  </bean>

?

?

?注：

用public class TestSpringBuild extends TestCase{ private AbstractApplicationContext ctx = null; @Before public void setUp() throws Exception { //ctx = new ClassPathXmlApplicationContext("bean.xml"); ctx = new FileSystemXmlApplicationContext("classpath:bean.xml"); } @After public void tearDown() throws Exception { ctx.close(); } @Test public void testBuild(){ StudentService studentService = (StudentService)ctx.getBean("studentService"); studentService.saveStudent(); }}

?