spring_Ioc

springIOC_Stu/src/main/java/com/wsstart/Demo.java

@@ -10,6 +10,7 @@ public class Demo {
         ClassPathXmlApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
 
         StudentDao studentDao = (StudentDao)app.getBean("studentDao");
+        StudentDao studentDao2 = (StudentDao)app.getBean("studentDao");
 
         Student student = studentDao.getStudentById(33);
 

springIOC_Stu/src/main/java/com/wsstart/dao/impl/StudentDaoImpl.java

@@ -5,6 +5,10 @@ import com.wsstart.domain.Student;
 
 public class StudentDaoImpl implements StudentDao {
 
+    public StudentDaoImpl() {
+        System.out.println("StudentDaoImpl创建了");
+    }
+
     public Student getStudentById(int id){
         return new Student("沃柑ouo",33,33);
     }

springIOC_Stu/src/main/resources/applicationContext.xml

@@ -4,5 +4,5 @@
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 
 
-    <bean class="com.wsstart.dao.impl.StudentDaoImpl" id="studentDao"></bean>
+    <bean class="com.wsstart.dao.impl.StudentDaoImpl" id="studentDao" scope="singleton"></bean>
 </beans>
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