fix javadoc

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

@@ -238,7 +238,7 @@ public class Site {
      * Put an Http header for downloader. <br>
      * Use {@link #addCookie(String, String)} for cookie and {@link #setUserAgent(String)} for user-agent. <br>
      *
-     * @param key   key of http header, there are some keys constant in {@link HeaderConst}
+     * @param key   key of http header, there are some keys constant in {@link HttpConstant.Header}
      * @param value value of header
      * @return this
      */

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

@@ -500,6 +500,7 @@ public class Spider implements Runnable, Task {
      * Download urls synchronizing.
      *
      * @param urls urls
+     * @param <T> type of process result
      * @return list downloaded
      */
     public <T> List<T> getAll(Collection<String> urls) {

webmagic-core/src/main/java/us/codecraft/webmagic/proxy/ProxyProvider.java

@@ -12,16 +12,17 @@ public interface ProxyProvider {
 
     /**
      *
-     * @param proxy
-     * @param page
-     * @param task
+     * Return proxy to Provider when complete a download.
+     * @param proxy the proxy config contains host,port and identify info
+     * @param page the download result
+     * @param task the download task
      */
     void returnProxy(Proxy proxy, Page page, Task task);
 
     /**
      * Get a proxy for task by some strategy.
-     * @param task task
-     * @return
+     * @param task the download task
+     * @return proxy 
      */
     Proxy getProxy(Task task);
     

webmagic-extension/src/main/java/us/codecraft/webmagic/downloader/PhantomJSDownloader.java

@@ -38,7 +38,7 @@ public class PhantomJSDownloader extends AbstractDownloader {
      *    phantomjs --ignore-ssl-errors=yes 忽略抓取地址是https时的一些错误
      *    /usr/local/bin/phantomjs 命令的绝对路径，避免因系统环境变量引起的IOException
      *   
-     * @param phantomJsCommand
+     * @param phantomJsCommand phantomJsCommand
      */
     public PhantomJSDownloader(String phantomJsCommand) {
         this.initPhantomjsCrawlPath();