package de.spring.example;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
import java.util.Map;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import de.spring.example.annotation.CustomTransactional;
+import de.spring.example.annotation.TestAnnotation;
public class AnnotationsHandler implements ApplicationContextAware, InitializingBean {
public void afterPropertiesSet() {
GenericBeanFactoryAccessor genericBeanFactoryAccessor = new GenericBeanFactoryAccessor(applicationContext);
+ //Spring searched the annotations configured in spring-config.xml file.
+ //With this code we can retrieve the Spring beans with those annotations.
final Map<String, Object> transactionalClass = genericBeanFactoryAccessor.getBeansWithAnnotation(CustomTransactional.class);
- for (final Object myFoo : transactionalClass.values()) {
- final Class<? extends Object> fooClass = myFoo.getClass();
- final CustomTransactional annotation = fooClass.getAnnotation(CustomTransactional.class);
- System.out.println("Found foo class: " + fooClass + ", with tags: ");
+ for (final Object annotationObject : transactionalClass.values())
+ {
+ final Class<? extends Object> annotationClass = annotationObject.getClass();
+ final CustomTransactional annotation = annotationClass.getAnnotation(CustomTransactional.class);
+ System.out.println("Found foo class: " + annotationClass + ", with annotation: " + annotation);
+ for (Method m : annotationClass.getDeclaredMethods())
+ {
+ //Another annotation just to show the nice thing about using annotations in Java.
+ //It requires Java reflection.
+ if (m.isAnnotationPresent(TestAnnotation.class))
+ {
+ try {
+ m.invoke(null);
+ //First of all we catch exception related to Java reflection.
+ } catch (IllegalArgumentException e) {
+ System.out.println(m + " failed: " + e.getCause());
+ } catch (IllegalAccessException e) {
+ System.out.println(m + " failed: " + e.getCause());
+ } catch (InvocationTargetException e) {
+ System.out.println(m + " failed: " + e.getCause());
+ } catch (Exception e)
+ {
+ //If the invoke method throws an exception we can catch it here
+ //and write a nice message.
+ System.out.println("INVALID method: " + m + ", something went wrong: " + e);
+ }
+ }
+ }
}
}
throws BeansException {
this.applicationContext = applicationContext;
}
- }
-
+ }
\ No newline at end of file
package de.spring.example;
import de.spring.example.annotation.CustomTransactional;
+import de.spring.example.annotation.TestAnnotation;
-
-public class Test {
- public void bar(){
- System.out.println("This is the containing class");
- }
-
- @CustomTransactional
- public class InnerService {
- public void innerMethod() {
- System.out.println("I am the inner class");
- }
- }
+public class Test {
+ public void bar(){
+ System.out.println("This is the containing class");
+ }
+
+ @CustomTransactional
+ public class InnerService {
+ @TestAnnotation
+ public void innerMethod() {
+ //System.out.println("I am the inner class");
+ }
+ }
}
--- /dev/null
+/**
+ *
+ */
+package de.spring.example.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ *
+ * We us this annotation to show how to invoke methods with annotations
+ * using Java reflection.
+ * This annotation will not be searched by Spring.
+ *
+ */
+
+@Target({ElementType.METHOD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface TestAnnotation {
+
+}
projects / JavaForFun / commitdiff