FilePipeline.java

package us.codecraft.webmagic.pipeline;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.log4j.Logger;
import us.codecraft.webmagic.ResultItems;
import us.codecraft.webmagic.Task;
import us.codecraft.webmagic.utils.FilePersistentBase;

import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;

/**
 * 持久化到文件的接口。
 *
 * @author code4crafter@gmail.com <br>
 *         Date: 13-4-21
 *         Time: 下午6:28
 */
public class FilePipeline extends FilePersistentBase implements Pipeline  {

    private Logger logger = Logger.getLogger(getClass());

    /**
     * 新建一个FilePipeline，使用默认保存路径"/data/webmagic/"
     */
    public FilePipeline() {
        setPath("/data/webmagic/");
    }

    /**
     * 新建一个FilePipeline
     *
     * @param path 文件保存路径
     */
    public FilePipeline(String path) {
        setPath(path);
    }

    @Override
    public void process(ResultItems resultItems, Task task) {
        String path = this.path + PATH_SEPERATOR + task.getUUID() + PATH_SEPERATOR;
        try {
            PrintWriter printWriter = new PrintWriter(new FileWriter(getFile(path + DigestUtils.md5Hex(resultItems.getRequest().getUrl()) + ".html")));
            printWriter.println("url:\t" + resultItems.getRequest().getUrl());
            for (Map.Entry<String, Object> entry : resultItems.getAll().entrySet()) {
                if (entry.getValue() instanceof Iterable) {
                    Iterable value = (Iterable) entry.getValue();
                    printWriter.println(entry.getKey() + ":");
                    for (Object o : value) {
                        printWriter.println(o);
                    }
                } else {
                    printWriter.println(entry.getKey() + ":\t" + entry.getValue());
                }
            }
            printWriter.close();
        } catch (IOException e) {
            logger.warn("write file error", e);
        }
    }
}