Add Site.defaultCharset. closes #1101.

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

@@ -28,6 +28,8 @@ public class Site {
 
     private String charset;
 
+    private String defaultCharset;
+
     private int sleepTime = 5000;
 
     private int retryTimes = 0;
@@ -168,6 +170,30 @@ public class Site {
         return charset;
     }
 
+    /**
+     * Set default charset of page.
+     *
+     * When charset detect failed, use this default charset.
+     *
+     * @param defaultCharset the default charset
+     * @return this
+     * @since 0.9.0
+     */
+    public Site setDefaultCharset(String defaultCharset) {
+        this.defaultCharset = defaultCharset;
+        return this;
+    }
+
+    /**
+     * The default charset if charset detected failed.
+     *
+     * @return the defulat charset
+     * @since 0.9.0
+     */
+    public String getDefaultCharset() {
+        return defaultCharset;
+    }
+
     public int getTimeOut() {
         return timeOut;
     }

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

@@ -4,6 +4,7 @@ import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.http.HttpResponse;
@@ -116,7 +117,7 @@ public class HttpClientDownloader extends AbstractDownloader {
         page.setBytes(bytes);
         if (!request.isBinaryContent()) {
             if (charset == null) {
-                charset = getHtmlCharset(contentType, bytes);
+                charset = getHtmlCharset(contentType, bytes, task);
             }
             page.setCharset(charset);
             page.setRawText(new String(bytes, charset));
@@ -131,11 +132,11 @@ public class HttpClientDownloader extends AbstractDownloader {
         return page;
     }
 
-    private String getHtmlCharset(String contentType, byte[] contentBytes) throws IOException {
+    private String getHtmlCharset(String contentType, byte[] contentBytes, Task task) throws IOException {
         String charset = CharsetUtils.detectCharset(contentType, contentBytes);
         if (charset == null) {
-            charset = Charset.defaultCharset().name();
-            logger.warn("Charset autodetect failed, use {} as charset. Please specify charset in Site.setCharset()", Charset.defaultCharset());
+            charset = Optional.ofNullable(task.getSite().getDefaultCharset()).orElseGet(Charset.defaultCharset()::name);
+            logger.info("Charset autodetect failed, use {} as charset.", task.getSite().getDefaultCharset());
         }
         return charset;
     }

webmagic-core/src/test/java/us/codecraft/webmagic/SiteTest.java

@@ -0,0 +1,17 @@
+package us.codecraft.webmagic;
+
+import static org.junit.Assert.assertEquals;
+
+import java.nio.charset.StandardCharsets;
+
+import org.junit.Test;
+
+public class SiteTest {
+
+    @Test
+    public void test() {
+        Site site = Site.me().setDefaultCharset(StandardCharsets.UTF_8.name());
+        assertEquals(StandardCharsets.UTF_8.name(), site.getDefaultCharset());
+    }
+
+}