🐛 #1161 微信支付修复EntPayRequest类的toString方法问题

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/bean/entpay/EntPayRequest.java

@@ -25,6 +25,8 @@ import me.chanjar.weixin.common.util.json.WxGsonBuilder;
 @AllArgsConstructor
 @XStreamAlias("xml")
 public class EntPayRequest extends BaseWxPayRequest {
+  private static final long serialVersionUID = 8647710192770447579L;
+
   /**
    * <pre>
    * 字段名：公众账号appid.
@@ -189,11 +191,6 @@ public class EntPayRequest extends BaseWxPayRequest {
     this.mchId = mchId;
   }
 
-  @Override
-  public String toString() {
-    return WxGsonBuilder.create().toJson(this);
-  }
-
   @Override
   protected String[] getIgnoredParamsForSign() {
     return new String[]{"sign_type"};