add a sample

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

@@ -87,6 +87,23 @@ public class Page {
         }
     }
 
+    /**
+     * add urls to fetch
+     *
+     * @param requests
+     */
+    public void addTargetRequests(List<String> requests,long priority) {
+        synchronized (targetRequests) {
+            for (String s : requests) {
+                if (StringUtils.isBlank(s) || s.equals("#") || s.startsWith("javascript:")) {
+                    break;
+                }
+                s = UrlUtils.canonicalizeUrl(s, url.toString());
+                targetRequests.add(new Request(s).setPriority(priority));
+            }
+        }
+    }
+
     /**
      * add url to fetch
      *

webmagic-samples/src/main/java/us/codecraft/webmagic/samples/scheduler/ZipCodePageProcessor.java

+package us.codecraft.webmagic.samples.scheduler;
+
+import org.apache.commons.lang3.StringUtils;
+import us.codecraft.webmagic.Page;
+import us.codecraft.webmagic.Request;
+import us.codecraft.webmagic.Site;
+import us.codecraft.webmagic.Spider;
+import us.codecraft.webmagic.processor.PageProcessor;
+import us.codecraft.webmagic.scheduler.PriorityScheduler;
+
+import java.util.List;
+
+import static us.codecraft.webmagic.selector.Selectors.regex;
+import static us.codecraft.webmagic.selector.Selectors.xpath;
+
+/**
+ * @author code4crafter@gmail.com
+ */
+public class ZipCodePageProcessor implements PageProcessor {
+
+    private Site site = Site.me().setCharset("gb2312").setSleepTime(0).addStartUrl("http://www.ip138.com/post/");
+
+    @Override
+    public void process(Page page) {
+        if (page.getUrl().toString().equals("http://www.ip138.com/post/")) {
+            processCountry(page);
+        } else if (page.getUrl().regex("http://www\\.ip138\\.com/post/\\w+[/]?$").toString() != null) {
+            processProvince(page);
+        } else {
+            processDistrict(page);
+        }
+
+    }
+
+    private void processCountry(Page page) {
+        List<String> provinces = page.getHtml().xpath("//*[@id=\"newAlexa\"]/table/tbody/tr/td").all();
+        for (String province : provinces) {
+            String link = xpath("//@href").select(province);
+            String title = xpath("/text()").select(province);
+            Request request = new Request(link).setPriority(0).putExtra("province", title);
+            page.addTargetRequest(request);
+        }
+    }
+
+    private void processProvince(Page page) {
+        //这里仅靠xpath没法精准定位，所以使用正则作为筛选，不符合正则的会被过滤掉
+        List<String> districts = page.getHtml().xpath("//body/table/tbody/tr/td").regex(".*http://www\\.ip138\\.com/post/\\w+/\\w+.*").all();
+        for (String district : districts) {
+            String link = xpath("//@href").select(district);
+            String title = xpath("/text()").select(district);
+            Request request = new Request(link).setPriority(1).putExtra("province", page.getRequest().getExtra("province")).putExtra("district", title);
+            page.addTargetRequest(request);
+        }
+    }
+
+    private void processDistrict(Page page) {
+        String province = page.getRequest().getExtra("province").toString();
+        String district = page.getRequest().getExtra("district").toString();
+        List<String> counties = page.getHtml().xpath("//body/table/tbody/tr").regex(".*<td>\\d+</td>.*").all();
+        String regex = "<td[^<>]*>([^<>]+)</td><td[^<>]*>([^<>]+)</td><td[^<>]*>([^<>]+)</td><td[^<>]*>([^<>]+)</td>";
+        for (String county : counties) {
+            String county0 = regex(regex, 1).select(county);
+            String county1 = regex(regex, 2).select(county);
+            String zipCode = regex(regex, 3).select(county);
+            page.putField("result", StringUtils.join(new String[]{province, district,
+                    county0, county1, zipCode}, "\t"));
+        }
+        List<String> links = page.getHtml().links().regex("http://www\\.ip138\\.com/post/\\w+/\\w+").all();
+        for (String link : links) {
+            page.addTargetRequest(new Request(link).setPriority(2).putExtra("province", province).putExtra("district", district));
+        }
+
+    }
+
+    @Override
+    public Site getSite() {
+        return site;
+    }
+
+    public static void main(String[] args) {
+        Spider.create(new ZipCodePageProcessor()).scheduler(new PriorityScheduler()).run();
+    }
+}