Merge pull request #269 from xsalefter/master
Initial commit for "Spring Custom Annotation with Dynamic Qualifier"
This commit is contained in:
Eugen
commit
1ef53e2f68
@ -0,0 +1,9 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import org.springframework.context.annotation.ComponentScan;
|
||||
import org.springframework.context.annotation.Configuration;
|
||||
|
||||
@Configuration
|
||||
@ComponentScan("org.baeldung.customannotation")
|
||||
public class CustomAnnotationConfiguration {
|
||||
}
|
||||
@ -0,0 +1,14 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import java.lang.annotation.Documented;
|
||||
import java.lang.annotation.ElementType;
|
||||
import java.lang.annotation.Retention;
|
||||
import java.lang.annotation.RetentionPolicy;
|
||||
import java.lang.annotation.Target;
|
||||
|
||||
@Retention(RetentionPolicy.RUNTIME)
|
||||
@Target({ ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD })
|
||||
@Documented
|
||||
public @interface DataAccess {
|
||||
Class<?>entity();
|
||||
}
|
||||
@ -0,0 +1,39 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import org.springframework.beans.BeansException;
|
||||
import org.springframework.beans.factory.annotation.Autowired;
|
||||
import org.springframework.beans.factory.config.BeanPostProcessor;
|
||||
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
|
||||
import org.springframework.stereotype.Component;
|
||||
import org.springframework.util.ReflectionUtils;
|
||||
import org.springframework.util.ReflectionUtils.FieldCallback;
|
||||
|
||||
@Component
|
||||
public class DataAccessAnnotationProcessor implements BeanPostProcessor {
|
||||
|
||||
private ConfigurableListableBeanFactory configurableListableBeanFactory;
|
||||
|
||||
@Autowired
|
||||
public DataAccessAnnotationProcessor(ConfigurableListableBeanFactory bf) {
|
||||
configurableListableBeanFactory = bf;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Object postProcessBeforeInitialization(Object bean, String beanName)
|
||||
throws BeansException {
|
||||
scanDataAccessAnnotation(bean, beanName);
|
||||
return bean;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Object postProcessAfterInitialization(Object bean, String beanName)
|
||||
throws BeansException {
|
||||
return bean;
|
||||
}
|
||||
|
||||
protected void scanDataAccessAnnotation(Object bean, String beanName) {
|
||||
Class<?> managedBeanClass = bean.getClass();
|
||||
FieldCallback fcb = new DataAccessFieldCallback(configurableListableBeanFactory, bean);
|
||||
ReflectionUtils.doWithFields(managedBeanClass, fcb);
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,104 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import java.lang.reflect.Constructor;
|
||||
import java.lang.reflect.Field;
|
||||
import java.lang.reflect.ParameterizedType;
|
||||
import java.lang.reflect.Type;
|
||||
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
|
||||
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
|
||||
import org.springframework.util.ReflectionUtils;
|
||||
import org.springframework.util.ReflectionUtils.FieldCallback;
|
||||
|
||||
|
||||
public final class DataAccessFieldCallback implements FieldCallback {
|
||||
|
||||
private static Logger logger = LoggerFactory.getLogger(DataAccessFieldCallback.class);
|
||||
private static int AUTOWIRE_MODE = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;
|
||||
|
||||
private static String ERROR_ENTITY_VALUE_NOT_SAME = "@DataAccess(entity) "
|
||||
+ "value should have same type with injected generic type.";
|
||||
private static String WARN_NON_GENERIC_VALUE = "@DataAccess annotation assigned "
|
||||
+ "to raw (non-generic) declaration. This will make your code less type-safe.";
|
||||
private static String ERROR_CREATE_INSTANCE = "Cannot create instance of "
|
||||
+ "type '{}' or instance creation is failed because: {}";
|
||||
|
||||
private ConfigurableListableBeanFactory configurableListableBeanFactory;
|
||||
private Object bean;
|
||||
|
||||
public DataAccessFieldCallback(final ConfigurableListableBeanFactory bf, final Object bean) {
|
||||
configurableListableBeanFactory = bf;
|
||||
this.bean = bean;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void doWith(final Field field)
|
||||
throws IllegalArgumentException, IllegalAccessException {
|
||||
if (!field.isAnnotationPresent(DataAccess.class)) {
|
||||
return;
|
||||
}
|
||||
ReflectionUtils.makeAccessible(field);
|
||||
final Type fieldGenericType = field.getGenericType();
|
||||
// In this example, get actual "GenericDAO' type.
|
||||
final Class<?> generic = field.getType();
|
||||
final Class<?> classValue = field.getDeclaredAnnotation(DataAccess.class).entity();
|
||||
|
||||
if (genericTypeIsValid(classValue, fieldGenericType)) {
|
||||
final String beanName = classValue.getSimpleName() + generic.getSimpleName();
|
||||
final Object beanInstance = getBeanInstance(beanName, generic, classValue);
|
||||
field.set(bean, beanInstance);
|
||||
} else {
|
||||
throw new IllegalArgumentException(ERROR_ENTITY_VALUE_NOT_SAME);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* For example, if user write:
|
||||
* <pre>
|
||||
* @DataAccess(entity=Person.class)
|
||||
* private GenericDAO<Account> personGenericDAO;
|
||||
* </pre>
|
||||
* then this is should be failed.
|
||||
*/
|
||||
public boolean genericTypeIsValid(final Class<?> clazz, final Type field) {
|
||||
if (field instanceof ParameterizedType) {
|
||||
final ParameterizedType parameterizedType = (ParameterizedType) field;
|
||||
final Type type = parameterizedType.getActualTypeArguments()[0];
|
||||
|
||||
return type.equals(clazz);
|
||||
} else {
|
||||
logger.warn(WARN_NON_GENERIC_VALUE);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
public final Object getBeanInstance(final String beanName, final Class<?> genericClass, final Class<?> paramClass) {
|
||||
Object daoInstance = null;
|
||||
if (!configurableListableBeanFactory.containsBean(beanName)) {
|
||||
logger.info("Creating new DataAccess bean named '{}'.", beanName);
|
||||
|
||||
Object toRegister = null;
|
||||
try {
|
||||
final Constructor<?> ctr = genericClass.getConstructor(Class.class);
|
||||
toRegister = ctr.newInstance(paramClass);
|
||||
} catch (final Exception e) {
|
||||
logger.error(ERROR_CREATE_INSTANCE, genericClass.getTypeName(), e);
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
|
||||
daoInstance = configurableListableBeanFactory.initializeBean(toRegister, beanName);
|
||||
configurableListableBeanFactory.autowireBeanProperties(daoInstance, AUTOWIRE_MODE, true);
|
||||
configurableListableBeanFactory.registerSingleton(beanName, daoInstance);
|
||||
logger.info("Bean named '{}' created successfully.", beanName);
|
||||
} else {
|
||||
daoInstance = configurableListableBeanFactory.getBean(beanName);
|
||||
logger.info("Bean named '{}' already exist used as current bean reference.", beanName);
|
||||
}
|
||||
return daoInstance;
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,30 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import java.util.Collections;
|
||||
import java.util.List;
|
||||
import java.util.Optional;
|
||||
|
||||
public class GenericDAO<E> {
|
||||
|
||||
private Class<E> entityClass;
|
||||
private String message;
|
||||
|
||||
public GenericDAO(Class<E> entityClass) {
|
||||
this.entityClass = entityClass;
|
||||
}
|
||||
|
||||
public List<E> findAll() {
|
||||
message = "Would create findAll query from " + entityClass.getSimpleName();
|
||||
return Collections.emptyList();
|
||||
}
|
||||
|
||||
public Optional<E> persist(E toPersist) {
|
||||
message = "Would create persist query from " + toPersist.getClass().getSimpleName();
|
||||
return Optional.empty();
|
||||
}
|
||||
|
||||
/** Only used for unit-testing. */
|
||||
public final String getMessage() {
|
||||
return message;
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,40 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import java.io.Serializable;
|
||||
|
||||
public class Account implements Serializable {
|
||||
|
||||
private static final long serialVersionUID = 7857541629844398625L;
|
||||
|
||||
private Long id;
|
||||
private String email;
|
||||
private Person person;
|
||||
|
||||
public Account() {
|
||||
}
|
||||
|
||||
public Long getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public void setId(Long id) {
|
||||
this.id = id;
|
||||
}
|
||||
|
||||
public String getEmail() {
|
||||
return email;
|
||||
}
|
||||
|
||||
public void setEmail(String email) {
|
||||
this.email = email;
|
||||
}
|
||||
|
||||
public Person getPerson() {
|
||||
return person;
|
||||
}
|
||||
|
||||
public void setPerson(Person person) {
|
||||
this.person = person;
|
||||
}
|
||||
|
||||
}
|
||||
@ -0,0 +1,17 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import org.springframework.stereotype.Repository;
|
||||
|
||||
@Repository
|
||||
public class BeanWithGenericDAO {
|
||||
|
||||
@DataAccess(entity=Person.class)
|
||||
private GenericDAO<Person> personGenericDAO;
|
||||
|
||||
public BeanWithGenericDAO() {}
|
||||
|
||||
public GenericDAO<Person> getPersonGenericDAO() {
|
||||
return personGenericDAO;
|
||||
}
|
||||
|
||||
}
|
||||
@ -0,0 +1,57 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import static org.hamcrest.CoreMatchers.equalTo;
|
||||
import static org.hamcrest.CoreMatchers.is;
|
||||
import static org.hamcrest.CoreMatchers.not;
|
||||
import static org.hamcrest.CoreMatchers.notNullValue;
|
||||
import static org.hamcrest.CoreMatchers.sameInstance;
|
||||
import static org.junit.Assert.assertThat;
|
||||
|
||||
import org.junit.Test;
|
||||
import org.junit.runner.RunWith;
|
||||
import org.springframework.test.context.ContextConfiguration;
|
||||
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
|
||||
|
||||
@RunWith(SpringJUnit4ClassRunner.class)
|
||||
@ContextConfiguration(classes = { CustomAnnotationConfiguration.class })
|
||||
public class DataAccessAnnotationTest {
|
||||
|
||||
@DataAccess(entity = Person.class)
|
||||
private GenericDAO<Person> personGenericDAO;
|
||||
@DataAccess(entity = Account.class)
|
||||
private GenericDAO<Account> accountGenericDAO;
|
||||
@DataAccess(entity = Person.class)
|
||||
private GenericDAO<Person> anotherPersonGenericDAO;
|
||||
|
||||
@Test
|
||||
public void whenGenericDAOInitialized_thenNotNull() {
|
||||
assertThat(personGenericDAO, is(notNullValue()));
|
||||
assertThat(accountGenericDAO, is(notNullValue()));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenGenericDAOInjected_thenItIsSingleton() {
|
||||
assertThat(personGenericDAO, not(sameInstance(accountGenericDAO)));
|
||||
assertThat(personGenericDAO, not(equalTo(accountGenericDAO)));
|
||||
|
||||
assertThat(personGenericDAO, sameInstance(anotherPersonGenericDAO));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenFindAll_thenMessagesIsCorrect() {
|
||||
personGenericDAO.findAll();
|
||||
assertThat(personGenericDAO.getMessage(), is("Would create findAll query from Person"));
|
||||
|
||||
accountGenericDAO.findAll();
|
||||
assertThat(accountGenericDAO.getMessage(), is("Would create findAll query from Account"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenPersist_thenMakeSureThatMessagesIsCorrect() {
|
||||
personGenericDAO.persist(new Person());
|
||||
assertThat(personGenericDAO.getMessage(), is("Would create persist query from Person"));
|
||||
|
||||
accountGenericDAO.persist(new Account());
|
||||
assertThat(accountGenericDAO.getMessage(), is("Would create persist query from Account"));
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,53 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import static org.hamcrest.CoreMatchers.is;
|
||||
import static org.hamcrest.CoreMatchers.notNullValue;
|
||||
import static org.junit.Assert.assertThat;
|
||||
|
||||
import java.lang.reflect.Type;
|
||||
|
||||
import org.junit.Rule;
|
||||
import org.junit.Test;
|
||||
import org.junit.rules.ExpectedException;
|
||||
import org.junit.runner.RunWith;
|
||||
import org.springframework.beans.factory.annotation.Autowired;
|
||||
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
|
||||
import org.springframework.test.context.ContextConfiguration;
|
||||
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
|
||||
|
||||
|
||||
@RunWith(SpringJUnit4ClassRunner.class)
|
||||
@ContextConfiguration(classes = { CustomAnnotationConfiguration.class })
|
||||
public class DataAccessFieldCallbackTest {
|
||||
|
||||
@Autowired
|
||||
private ConfigurableListableBeanFactory configurableListableBeanFactory;
|
||||
|
||||
@Autowired
|
||||
private BeanWithGenericDAO beanWithGenericDAO;
|
||||
|
||||
@Rule
|
||||
public ExpectedException ex = ExpectedException.none();
|
||||
|
||||
@Test
|
||||
public void whenObjectCreated_thenObjectCreationIsSuccessful() {
|
||||
final DataAccessFieldCallback dataAccessFieldCallback = new DataAccessFieldCallback(configurableListableBeanFactory, beanWithGenericDAO);
|
||||
assertThat(dataAccessFieldCallback, is(notNullValue()));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenMethodGenericTypeIsValidCalled_thenReturnCorrectValue()
|
||||
throws NoSuchFieldException, SecurityException {
|
||||
final DataAccessFieldCallback callback = new DataAccessFieldCallback(configurableListableBeanFactory, beanWithGenericDAO);
|
||||
final Type fieldType = BeanWithGenericDAO.class.getDeclaredField("personGenericDAO").getGenericType();
|
||||
final boolean result = callback.genericTypeIsValid(Person.class, fieldType);
|
||||
assertThat(result, is(true));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenMethodGetBeanInstanceCalled_thenReturnCorrectInstance() {
|
||||
final DataAccessFieldCallback callback = new DataAccessFieldCallback(configurableListableBeanFactory, beanWithGenericDAO);
|
||||
final Object result = callback.getBeanInstance("personGenericDAO", GenericDAO.class, Person.class);
|
||||
assertThat((result instanceof GenericDAO), is(true));
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,31 @@
|
||||
package org.baeldung.customannotation;
|
||||
|
||||
import java.io.Serializable;
|
||||
|
||||
public class Person implements Serializable {
|
||||
|
||||
private static final long serialVersionUID = 9005331414216374586L;
|
||||
|
||||
private Long id;
|
||||
private String name;
|
||||
|
||||
public Person() {
|
||||
}
|
||||
|
||||
public Long getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public void setId(Long id) {
|
||||
this.id = id;
|
||||
}
|
||||
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
public void setName(String name) {
|
||||
this.name = name;
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user