add multithread support

webmagic-core/src/main/java/us/codecraft/webmagic/Spider.java

@@ -9,9 +9,12 @@ import us.codecraft.webmagic.pipeline.Pipeline;
 import us.codecraft.webmagic.processor.PageProcessor;
 import us.codecraft.webmagic.schedular.QueueScheduler;
 import us.codecraft.webmagic.schedular.Scheduler;
+import us.codecraft.webmagic.utils.ThreadUtils;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * <pre>
@@ -51,6 +54,16 @@ public class Spider implements Runnable, Task {
 
     private Logger logger = Logger.getLogger(getClass());
 
+    private ExecutorService executorService;
+
+    private AtomicInteger stat = new AtomicInteger(STAT_INIT);
+
+    private final static int STAT_INIT = 0;
+
+    private final static int STAT_RUNNING = 1;
+
+    private final static int STAT_STOPPED = 2;
+
     /**
      * 使用已定义的抽取规则新建一个Spider。
      * @param pageProcessor 已定义的抽取规则
@@ -76,6 +89,7 @@ public class Spider implements Runnable, Task {
      * @return this
      */
     public Spider startUrls(List<String> startUrls) {
+        checkIfNotRunning();
         this.startUrls = startUrls;
         return this;
     }
@@ -96,6 +110,7 @@ public class Spider implements Runnable, Task {
      * @return this
      */
     public Spider scheduler(Scheduler scheduler) {
+        checkIfNotRunning();
         this.scheduler = scheduler;
         return this;
     }
@@ -106,6 +121,7 @@ public class Spider implements Runnable, Task {
      * @return this
      */
     public Spider pipeline(Pipeline pipeline) {
+        checkIfNotRunning();
         this.pipelines.add(pipeline);
         return this;
     }
@@ -113,6 +129,9 @@ public class Spider implements Runnable, Task {
 
     @Override
     public void run() {
+        if (!stat.compareAndSet(STAT_INIT, STAT_RUNNING)) {
+            throw new IllegalStateException("Spider is already running!");
+        }
         if (startUrls != null) {
             for (String startUrl : startUrls) {
                 scheduler.push(new Request(startUrl), this);
@@ -122,20 +141,56 @@ public class Spider implements Runnable, Task {
         if (pipelines.isEmpty()) {
             pipelines.add(new ConsolePipeline());
         }
-        while (request != null) {
-            Page page = downloader.download(request, site);
-            if (page == null) {
-                sleep(site.getSleepTime());
-                continue;
+        //singel thread
+        if (executorService==null){
+            while (request != null) {
+                processRequest(request);
+                request = scheduler.poll(this);
             }
-            pageProcessor.process(page);
-            addRequest(page);
-            for (Pipeline pipeline : pipelines) {
-                pipeline.process(page, this);
+        } else {
+            final AtomicInteger threadAlive = new AtomicInteger(0);
+            while (true) {
+                if (request == null) {
+                    try {
+                        Thread.sleep(100);
+                    } catch (InterruptedException e) {
+                    }
+                } else {
+                    final Request requestFinal = request;
+                    threadAlive.incrementAndGet();
+                    executorService.execute(new Runnable() {
+                        @Override
+                        public void run() {
+                            processRequest(requestFinal);
+                            threadAlive.decrementAndGet();
+                        }
+                    });
+                }
+                request = scheduler.poll(this);
+                if (threadAlive.get() == 0) {
+                    request = scheduler.poll(this);
+                    if (request == null) {
+                        break;
+                    }
+                }
             }
-            sleep(site.getSleepTime());
-            request = scheduler.poll(this);
+            executorService.shutdown();
         }
+        stat.compareAndSet(STAT_RUNNING, STAT_STOPPED);
+    }
+
+    private void processRequest(Request request) {
+        Page page = downloader.download(request, site);
+        if (page == null) {
+            sleep(site.getSleepTime());
+            return;
+        }
+        pageProcessor.process(page);
+        addRequest(page);
+        for (Pipeline pipeline : pipelines) {
+            pipeline.process(page, this);
+        }
+        sleep(site.getSleepTime());
     }
 
     private void sleep(int time) {
@@ -154,6 +209,28 @@ public class Spider implements Runnable, Task {
         }
     }
 
+    private void checkIfNotRunning(){
+        if (!stat.compareAndSet(STAT_INIT,STAT_INIT)){
+            throw new IllegalStateException("Spider is already running!");
+        }
+    }
+
+    /**
+     * 建立多个线程下载
+     * @param threadNum 线程数
+     * @return
+     */
+    public Spider thread(int threadNum) {
+        checkIfNotRunning();
+        if (threadNum <= 1) {
+            throw new IllegalArgumentException("threadNum should be more than one!");
+        }
+        synchronized (this){
+            this.executorService = ThreadUtils.newFixedThreadPool(threadNum);
+        }
+        return this;
+    }
+
     @Override
     public String getUUID() {
         if (uuid != null) {

webmagic-core/src/main/java/us/codecraft/webmagic/utils/ThreadUtils.java

@@ -0,0 +1,33 @@
+package us.codecraft.webmagic.utils;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * @author code4crafer@gmail.com
+ *         Date: 13-6-23
+ *         Time: 下午7:11
+ */
+public class ThreadUtils {
+
+    public static ExecutorService newFixedThreadPool(int threadSize) {
+        return new ThreadPoolExecutor(threadSize, threadSize, 0L, TimeUnit.MILLISECONDS,
+                new LinkedBlockingQueue<Runnable>(1) {
+
+                    private static final long serialVersionUID = -9028058603126367678L;
+
+                    @Override
+                    public boolean offer(Runnable e) {
+                        try {
+                            put(e);
+                            return true;
+                        } catch (InterruptedException ie) {
+                            Thread.currentThread().interrupt();
+                        }
+                        return false;
+                    }
+                });
+    }
+}