cn.wanghaomiao.seimi.core.SeimiScanner Maven / Gradle / Ivy

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一个支持分布式的可以高效开发且可以高效运行的爬虫框架。设计思想上融合了spring与scrapy的优点。
There is a newer version: 2.1.4
package cn.wanghaomiao.seimi.core;
/*
   Copyright 2015 Wang Haomiao

   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.
 */

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
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;
import org.springframework.util.CollectionUtils;

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;

/**
 * 上下文加载器
 * @author 汪浩淼 [email protected]
 * @since 2015/6/17.
 */
public class SeimiScanner {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private static final String RESOURCE_PATTERN = "**/%s/**/*.class";
    private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
    private AnnotationConfigApplicationContext context;

    public SeimiScanner(AnnotationConfigApplicationContext context){
        this.context = context;
    }

    @SafeVarargs
    public final Set> scan(String[] confPkgs, Class... annotationTags){
        Set> resClazzSet = new HashSet<>();
        List typeFilters = new LinkedList<>();
        if (ArrayUtils.isNotEmpty(annotationTags)){
            for (Class annotation : annotationTags) {
                typeFilters.add(new AnnotationTypeFilter(annotation, false));
            }
        }
        if (ArrayUtils.isNotEmpty(confPkgs)) {
            for (String pkg : confPkgs) {
                String pattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX  + String.format(RESOURCE_PATTERN,ClassUtils.convertClassNameToResourcePath(pkg));
                try {
                    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 (ifMatchesEntityType(reader, readerFactory,typeFilters)) {
                                Class curClass = Thread.currentThread().getContextClassLoader().loadClass(className);
                                context.register(curClass);
                                resClazzSet.add(curClass);
                            }
                        }
                    }
                } catch (Exception e) {
                    logger.error("扫描提取[{}]包路径下，标记了注解[{}]的类出现异常", pattern,StringUtils.join(typeFilters,","));
                }
            }
        }
        if (!context.isActive()){
            context.refresh();
        }
        return resClazzSet;
    }

    /**
     * 检查当前扫描到的类是否含有任何一个指定的注解标记
     * @param reader
     * @param readerFactory
     * @return ture/false
     */
    private boolean ifMatchesEntityType(MetadataReader reader, MetadataReaderFactory readerFactory,List typeFilters) {
        if (!CollectionUtils.isEmpty(typeFilters)) {
            for (TypeFilter filter : typeFilters) {
                try {
                    if (filter.match(reader, readerFactory)) {
                        return true;
                    }
                } catch (IOException e) {
                    logger.error("过滤匹配类型时出错 {}",e.getMessage());
                }
            }
        }
        return false;
    }
}