net.javacoding.jspider.core.task.work.SerializableSpiderHttpURLTask.java Source code

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Here is the source code for net.javacoding.jspider.core.task.work.SerializableSpiderHttpURLTask.java

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package net.javacoding.jspider.core.task.work;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import net.javacoding.jspider.api.model.Site;
import net.javacoding.jspider.core.SpiderContext;
import net.javacoding.jspider.core.task.WorkerTask;
import net.javacoding.jspider.core.util.URLUtil;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 *
 * @author changshu.li
 */
public class SerializableSpiderHttpURLTask implements WorkerTask, Serializable {

    private static Log log = LogFactory.getLog(SerializableSpiderHttpURLTask.class);
    private final static Map<String, SpiderContext> contexts = new HashMap();

    private URL foundURL;
    private String contextToString;
    transient private SpiderHttpURLTask task;
    transient private SpiderContext context;

    /**
     * each SpiderContext must have different cache dir !!
     *
     * @param context
     * @param foundURL
     * @return
     */
    public static SerializableSpiderHttpURLTask createCacheFlagWorkerTask(SpiderContext context, URL foundURL) {
        if (!contexts.containsKey(context.toString())) {
            synchronized (SerializableSpiderHttpURLTask.class) {
                if (contexts.get(context.toString()) == null) {
                    contexts.put(context.toString(), context);
                }
            }
        } else {
            if (contexts.get(context.toString()) != context) {
                throw new RuntimeException("Different context must has different toString result !");
            }
        }
        return new SerializableSpiderHttpURLTask(context, foundURL);
    }

    public SerializableSpiderHttpURLTask(SpiderContext context, URL findURL) {
        this.context = context;
        this.foundURL = findURL;
        this.contextToString = context.toString();
    }

    @Override
    public void prepare() {
        URL siteURL = URLUtil.getSiteURL(this.foundURL);
        Site site = context.getStorage().getSiteDAO().find(siteURL);
        task = new SpiderHttpURLTask(context, foundURL, site);
        task.prepare();
    }

    @Override
    public void execute() {
        if (task == null) {
            log.error("Must run prepare first !");
        } else {
            task.execute();
        }
    }

    //=======================
    //?
    private void writeObject(ObjectOutputStream out) throws IOException {
        out.defaultWriteObject();
        out.writeObject(this.foundURL);
        out.writeObject(this.contextToString);
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        in.defaultReadObject();
        this.foundURL = (URL) in.readObject();
        this.contextToString = (String) in.readObject();
        this.context = contexts.get(contextToString);
        if (this.context == null) {
            throw new IOException("Not find context !");
        }
    }

    @Override
    public int getType() {
        return WorkerTask.WORKERTASK_SPIDERTASK;
    }

    @Override
    public void tearDown() {
        context.getAgent().flagDone(this);
        task.tearDown();
    }
}