替换hard code

Author: binarywang

weixin-java-mp/src/main/java/me/chanjar/weixin/mp/api/WxMpServiceImpl.java

@@ -27,6 +27,8 @@
 import me.chanjar.weixin.mp.bean.result.*;
 import me.chanjar.weixin.mp.util.http.*;
 import me.chanjar.weixin.mp.util.json.WxMpGsonBuilder;
+
+import org.apache.commons.io.Charsets;
 import org.apache.http.Consts;
 import org.apache.http.HttpHost;
 import org.apache.http.client.ClientProtocolException;
@@ -48,6 +50,7 @@
 import java.io.StringReader;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
+import java.nio.charset.Charset;
 import java.security.NoSuchAlgorithmException;
 import java.util.*;
 import java.util.Map.Entry;
@@ -478,7 +481,7 @@ public File qrCodePicture(WxMpQrCodeTicket ticket) throws WxErrorException {
   public String qrCodePictureUrl(String ticket) throws WxErrorException {
     String url = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=%s";
     try {
-      return String.format(url, URLEncoder.encode(ticket, "utf-8"));
+      return String.format(url, URLEncoder.encode(ticket, Charsets.UTF_8.name()));
     } catch (UnsupportedEncodingException e) {
       WxError error = new WxError();
       error.setErrorCode(-1);