spring扫描annotation

import java.io.IOException;
import java.lang.annotation.Annotation;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
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.TypeFilter;
import org.springframework.util.ClassUtils;

/**
 * 扫描包中的类
 */

public class LoadPackageClasses {

    private static final String RESOURCE_PATTERN = "/**/*.class";

    private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
 
    private List<String> packagesList = new LinkedList<String>();

    private List<TypeFilter> typeFilters = new LinkedList<TypeFilter>();
    
    private Set<Class<?>> classSet = new HashSet<Class<?>>();

    /**
     *eg: <pre name="code" class="java">     *   String[] cs = new String[1];
     *   cs[0] = "com.wz.test";
     *   LoadPackageClasses l = new LoadPackageClasses(cs,
     *           org.springframework.stereotype.Controller.class);
     * l.getClassSet();
     */
    public LoadPackageClasses ( String[] packagesToScan, Class<? extends Annotation>... annotationFilter) {
        if (packagesToScan != null) {
            for (String packagePath : packagesToScan) {
                this.packagesList.add(packagePath);
            }
        }
        if (annotationFilter != null) {
            for (Class<? extends Annotation> annotation : annotationFilter) {
                typeFilters.add(new AnnotationTypeFilter(annotation, false));
            }
        }
   }

    public Set<Class<?>> getClassSet() throws IOException, ClassNotFoundException {
        this.classSet.clear();
        if (!this.packagesList.isEmpty()) {
            for (String pkg : this.packagesList) {
                String pattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
                        + ClassUtils.convertClassNameToResourcePath(pkg)
                        + RESOURCE_PATTERN;
                Resource[] resources = this.resourcePatternResolver.getResources(pattern);
                MetadataReaderFactory readerFactory = new CachingMetadataReaderFactory(this.resourcePatternResolver);
                for (Resource resource : resources) {
                    if (resource.isReadable()) {
                        MetadataReader reader = readerFactory.getMetadataReader(resource);
                        String className = reader.getClassMetadata().getClassName();
                        if (matchesEntityTypeFilter(reader,readerFactory)) {
                            this.classSet.add(Class.forName(className));
                        }
                    }
                }
            }
        }
        return this.classSet;
    }

    /**
     * 检查注解
     */
    private boolean matchesEntityTypeFilter(MetadataReader reader, MetadataReaderFactory readerFactory) throws IOException {
        if (!this.typeFilters.isEmpty()) {
            for (TypeFilter filter : this.typeFilters) {
                if (filter.match(reader, readerFactory)) {
                    return true;
                }
            }
        }
        return false;
    }
}