ClassPathMapperScanner.java

/*
 *    Copyright 2010-2013 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.mybatis.spring.mapper;

import java.io.IOException;
import java.lang.annotation.Annotation;
import java.util.Arrays;
import java.util.Set;

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionTemplate;

import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.context.annotation.ClassPathBeanDefinitionScanner;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.core.type.filter.AnnotationTypeFilter;
import org.springframework.core.type.filter.AssignableTypeFilter;
import org.springframework.core.type.filter.TypeFilter;
import org.springframework.util.StringUtils;

/**
 * A {@link ClassPathBeanDefinitionScanner} that registers Mappers by
 * {@code basePackage}, {@code annotationClass}, or {@code markerInterface}. If
 * an {@code annotationClass} and/or {@code markerInterface} is specified, only
 * the specified types will be searched (searching for all interfaces will be
 * disabled).
 * <p>
 * This functionality was previously a private class of
 * {@link MapperScannerConfigurer}, but was broken out in version 1.2.0.
 *
 * @author Hunter Presnall
 * @author Eduardo Macarron
 * 
 * @see MapperFactoryBean
 * @since 1.2.0
 * @version $Id$
 */
public class ClassPathMapperScanner extends ClassPathBeanDefinitionScanner {

  private boolean addToConfig = true;

  private SqlSessionFactory sqlSessionFactory;

  private SqlSessionTemplate sqlSessionTemplate;

  private String sqlSessionTemplateBeanName;

  private String sqlSessionFactoryBeanName;

  private Class<? extends Annotation> annotationClass;

  private Class<?> markerInterface;

  public ClassPathMapperScanner(BeanDefinitionRegistry registry) {
    super(registry, false);
  }

  public void setAddToConfig(boolean addToConfig) {
    this.addToConfig = addToConfig;
  }

  public void setAnnotationClass(Class<? extends Annotation> annotationClass) {
    this.annotationClass = annotationClass;
  }

  public void setMarkerInterface(Class<?> markerInterface) {
    this.markerInterface = markerInterface;
  }

  public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
    this.sqlSessionFactory = sqlSessionFactory;
  }

  public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
    this.sqlSessionTemplate = sqlSessionTemplate;
  }

  public void setSqlSessionTemplateBeanName(String sqlSessionTemplateBeanName) {
    this.sqlSessionTemplateBeanName = sqlSessionTemplateBeanName;
  }

  public void setSqlSessionFactoryBeanName(String sqlSessionFactoryBeanName) {
    this.sqlSessionFactoryBeanName = sqlSessionFactoryBeanName;
  }

  /**
   * Configures parent scanner to search for the right interfaces. It can search
   * for all interfaces or just for those that extends a markerInterface or/and
   * those annotated with the annotationClass
   */
  public void registerFilters() {
    boolean acceptAllInterfaces = true;

    // if specified, use the given annotation and / or marker interface
    if (this.annotationClass != null) {
      addIncludeFilter(new AnnotationTypeFilter(this.annotationClass));
      acceptAllInterfaces = false;
    }

    // override AssignableTypeFilter to ignore matches on the actual marker interface
    if (this.markerInterface != null) {
      addIncludeFilter(new AssignableTypeFilter(this.markerInterface) {
        @Override
        protected boolean matchClassName(String className) {
          return false;
        }
      });
      acceptAllInterfaces = false;
    }

    if (acceptAllInterfaces) {
      // default include filter that accepts all classes
      addIncludeFilter(new TypeFilter() {
        public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException {
          return true;
        }
      });
    }

    // exclude package-info.java
    addExcludeFilter(new TypeFilter() {
      public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException {
        String className = metadataReader.getClassMetadata().getClassName();
        return className.endsWith("package-info");
      }
    });
  }

  /**
   * Calls the parent search that will search and register all the candidates.
   * Then the registered objects are post processed to set them as
   * MapperFactoryBeans
   */
  @Override
  public Set<BeanDefinitionHolder> doScan(String... basePackages) {
    Set<BeanDefinitionHolder> beanDefinitions = super.doScan(basePackages);

    if (beanDefinitions.isEmpty()) {
      logger.warn("No MyBatis mapper was found in '" + Arrays.toString(basePackages) + "' package. Please check your configuration.");
    } else {
      for (BeanDefinitionHolder holder : beanDefinitions) {
        GenericBeanDefinition definition = (GenericBeanDefinition) holder.getBeanDefinition();

        if (logger.isDebugEnabled()) {
          logger.debug("Creating MapperFactoryBean with name '" + holder.getBeanName() 
              + "' and '" + definition.getBeanClassName() + "' mapperInterface");
        }

        // the mapper interface is the original class of the bean
        // but, the actual class of the bean is MapperFactoryBean
		
		// 此处使用addPropertyValue方法,Spring2.5的MutablePropertyValues
		// 没有add(String propertyName, Object propertyValue)方法
        definition.getPropertyValues().addPropertyValue("mapperInterface", definition.getBeanClassName());
        definition.setBeanClass(MapperFactoryBean.class);

        definition.getPropertyValues().addPropertyValue("addToConfig", this.addToConfig);

        boolean explicitFactoryUsed = false;
        if (StringUtils.hasText(this.sqlSessionFactoryBeanName)) {
          definition.getPropertyValues().addPropertyValue("sqlSessionFactory", new RuntimeBeanReference(this.sqlSessionFactoryBeanName));
          explicitFactoryUsed = true;
        } else if (this.sqlSessionFactory != null) {
          definition.getPropertyValues().addPropertyValue("sqlSessionFactory", this.sqlSessionFactory);
          explicitFactoryUsed = true;
        }

        if (StringUtils.hasText(this.sqlSessionTemplateBeanName)) {
          if (explicitFactoryUsed) {
            logger.warn("Cannot use both: sqlSessionTemplate and sqlSessionFactory together. sqlSessionFactory is ignored.");
          }
          definition.getPropertyValues().addPropertyValue("sqlSessionTemplate", new RuntimeBeanReference(this.sqlSessionTemplateBeanName));
          explicitFactoryUsed = true;
        } else if (this.sqlSessionTemplate != null) {
          if (explicitFactoryUsed) {
            logger.warn("Cannot use both: sqlSessionTemplate and sqlSessionFactory together. sqlSessionFactory is ignored.");
          }
          definition.getPropertyValues().addPropertyValue("sqlSessionTemplate", this.sqlSessionTemplate);
          explicitFactoryUsed = true;
        }

        if (!explicitFactoryUsed) {
          if (logger.isDebugEnabled()) {
            logger.debug("Enabling autowire by type for MapperFactoryBean with name '" + holder.getBeanName() + "'.");
          }
          definition.setAutowireMode(AbstractBeanDefinition.AUTOWIRE_BY_TYPE);
        }
      }
    }

    return beanDefinitions;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition) {
    return (beanDefinition.getMetadata().isInterface() && beanDefinition.getMetadata().isIndependent());
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected boolean checkCandidate(String beanName, BeanDefinition beanDefinition) throws IllegalStateException {
    if (super.checkCandidate(beanName, beanDefinition)) {
      return true;
    } else {
      logger.warn("Skipping MapperFactoryBean with name '" + beanName 
          + "' and '" + beanDefinition.getBeanClassName() + "' mapperInterface"
          + ". Bean already defined with the same name!");
      return false;
    }
  }

}