refactor:extract charset detect to utils

webmagic-core/src/main/java/us/codecraft/webmagic/downloader/HttpClientDownloader.java

@@ -1,7 +1,6 @@
 package us.codecraft.webmagic.downloader;
 
 import org.apache.commons.io.IOUtils;
-import org.apache.commons.lang3.StringUtils;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpResponse;
 import org.apache.http.NameValuePair;
@@ -13,10 +12,6 @@ import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.client.methods.RequestBuilder;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.util.EntityUtils;
-import org.jsoup.Jsoup;
-import org.jsoup.nodes.Document;
-import org.jsoup.nodes.Element;
-import org.jsoup.select.Elements;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import us.codecraft.webmagic.Page;
@@ -25,8 +20,8 @@ import us.codecraft.webmagic.Site;
 import us.codecraft.webmagic.Task;
 import us.codecraft.webmagic.proxy.Proxy;
 import us.codecraft.webmagic.selector.PlainText;
+import us.codecraft.webmagic.utils.CharsetUtils;
 import us.codecraft.webmagic.utils.HttpConstant;
-import us.codecraft.webmagic.utils.UrlUtils;
 import us.codecraft.webmagic.utils.WMCollections;
 
 import java.io.IOException;
@@ -213,40 +208,6 @@ public class HttpClientDownloader extends AbstractDownloader {
     }
 
     protected String getHtmlCharset(HttpResponse httpResponse, byte[] contentBytes) throws IOException {
-        String charset;
-        // charset
-        // 1、encoding in http header Content-Type
-        String value = httpResponse.getEntity().getContentType().getValue();
-        charset = UrlUtils.getCharset(value);
-        if (StringUtils.isNotBlank(charset)) {
-            logger.debug("Auto get charset: {}", charset);
-            return charset;
-        }
-        // use default charset to decode first time
-        Charset defaultCharset = Charset.defaultCharset();
-        String content = new String(contentBytes, defaultCharset.name());
-        // 2、charset in meta
-        if (StringUtils.isNotEmpty(content)) {
-            Document document = Jsoup.parse(content);
-            Elements links = document.select("meta");
-            for (Element link : links) {
-                // 2.1、html4.01 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-                String metaContent = link.attr("content");
-                String metaCharset = link.attr("charset");
-                if (metaContent.indexOf("charset") != -1) {
-                    metaContent = metaContent.substring(metaContent.indexOf("charset"), metaContent.length());
-                    charset = metaContent.split("=")[1];
-                    break;
-                }
-                // 2.2、html5 <meta charset="UTF-8" />
-                else if (StringUtils.isNotEmpty(metaCharset)) {
-                    charset = metaCharset;
-                    break;
-                }
-            }
-        }
-        logger.debug("Auto get charset: {}", charset);
-        // 3、todo use tools as cpdetector for content decode
-        return charset;
+        return CharsetUtils.detectCharset(httpResponse.getEntity().getContentType().getValue(), contentBytes);
     }
 }

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

@@ -0,0 +1,61 @@
+package us.codecraft.webmagic.utils;
+
+import org.apache.commons.lang3.StringUtils;
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.jsoup.select.Elements;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+
+/**
+ * @author code4crafter@gmail.com
+ *         Date: 17/3/11
+ *         Time: 10:36
+ * @since 0.6.2
+ */
+public abstract class CharsetUtils {
+
+    private static Logger logger = LoggerFactory.getLogger(CharsetUtils.class);
+
+    public static String detectCharset(String contentType, byte[] contentBytes) throws IOException {
+        String charset;
+        // charset
+        // 1、encoding in http header Content-Type
+        charset = UrlUtils.getCharset(contentType);
+        if (StringUtils.isNotBlank(contentType)) {
+            logger.debug("Auto get charset: {}", charset);
+            return charset;
+        }
+        // use default charset to decode first time
+        Charset defaultCharset = Charset.defaultCharset();
+        String content = new String(contentBytes, defaultCharset);
+        // 2、charset in meta
+        if (StringUtils.isNotEmpty(content)) {
+            Document document = Jsoup.parse(content);
+            Elements links = document.select("meta");
+            for (Element link : links) {
+                // 2.1、html4.01 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+                String metaContent = link.attr("content");
+                String metaCharset = link.attr("charset");
+                if (metaContent.indexOf("charset") != -1) {
+                    metaContent = metaContent.substring(metaContent.indexOf("charset"), metaContent.length());
+                    charset = metaContent.split("=")[1];
+                    break;
+                }
+                // 2.2、html5 <meta charset="UTF-8" />
+                else if (StringUtils.isNotEmpty(metaCharset)) {
+                    charset = metaCharset;
+                    break;
+                }
+            }
+        }
+        logger.debug("Auto get charset: {}", charset);
+        // 3、todo use tools as cpdetector for content decode
+        return charset;
+    }
+    
+}