Mailgun Java API 发送 HTML 封电子邮件
Mailgun Java API send HTML emails
我正在尝试获取
"html": "... entire contents of HTML page goes here ..." 在 Java 中使用 Unirest HTTP 与 MailGun API 通信。
到目前为止，我已经验证了我的域，通过 API 成功发送了一封电子邮件，并通过 Java 中的 API 成功发送了一封 HTML（基本）电子邮件].
每当我尝试使用任何电子邮件模板时，我都无法发送电子邮件（通过 API，在 Java 中）。我试图使用此处推荐的电子邮件模板：https://github.com/mailgun/transactional-email-templates/tree/master/templates .
我发送邮件的代码与文档一致
public static JsonNode sendSimpleMessage() throws UnirestException {
HttpResponse<com.mashape.unirest.http.JsonNode> request = Unirest.post("https://api.mailgun.net/v3/sub.domain.com" + "/messages")
.basicAuth("api", API_KEY)
.queryString("from", "name <test@domain.com>")
.queryString("to", "myemail@gmail.com")
.queryString("subject", "Great")
.queryString("html", returnEmail())
.asJson();
return request.getBody();
}
public static String returnEmail() {
try {
return StreamUtils.copyToString(new ClassPathResource("email.html").getInputStream(), Charset.defaultCharset());
} catch (IOException e) {
e.printStackTrace();
}
return "<html><strong>not today</strong></html>";
}
并且 email.html 包含来自上述电子邮件 (https://github.com/mailgun/transactional-email-templates/tree/master/templates) 或任何 HTML 电子邮件的示例，因为 none 有效。
我得到的错误是：
com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1].
堆栈跟踪：
com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:143)
at com.mashape.unirest.request.BaseRequest.asJson(BaseRequest.java:68)
at com..application.ApplicationController.sendSimpleMessage(ApplicationController.java:78)
at com.application.ApplicationController.create(ApplicationController.java:61)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.HttpResponse.<init>(HttpResponse.java:106)
at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:139)
... 57 more
Caused by: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.JsonNode.<init>(JsonNode.java:51)
at com.mashape.unirest.http.HttpResponse.<init>(HttpResponse.java:95)
... 58 more
Caused by: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at org.json.JSONTokener.syntaxError(JSONTokener.java:433)
at org.json.JSONArray.<init>(JSONArray.java:105)
at org.json.JSONArray.<init>(JSONArray.java:144)
at com.mashape.unirest.http.JsonNode.<init>(JsonNode.java:48)
... 59 more
如果我只是将所有 HTML 粘贴为字符串而不是 returnEmail()，我也会遇到同样的错误。如果我在发送前转义特殊字符 and/or 缩小 HTML，我也会收到相同的错误消息。
现在我假设 Unirest 是一个 http 库，它从 queryString 键和值构建一个 JSON。虽然它似乎与 simpel html 一起工作，例如“HTML version whatever ，但它肯定不喜欢任何冗长的/'normal' html ，例如电子邮件模板。
能否请您为使用 Java API 的 html 电子邮件建议任何工作示例，或任何关于如何发送 html 并具有有效 json?
非常感谢
从您共享的 html 个文件中，使用正文中的 html，删除所有其他标签，它应该可以正常工作 post。
例如。来自文件 - https://github.com/mailgun/transactional-email-templates/blob/master/templates/alert.html
仅使用下面提到的 html。
<table class="body-wrap">
<tr>
<td></td>
<td class="container" width="600">
<div class="content">
<table class="main" width="100%" cellpadding="0" cellspacing="0">
<tr>
<td class="alert alert-warning">
Warning: You're approaching your limit. Please upgrade.
</td>
</tr>
<tr>
<td class="content-wrap">
<table width="100%" cellpadding="0" cellspacing="0">
<tr>
<td class="content-block">
You have <strong>1 free report</strong> remaining.
</td>
</tr>
<tr>
<td class="content-block">
Add your credit card now to upgrade your account to a premium plan to ensure you don't miss out on any reports.
</td>
</tr>
<tr>
<td class="content-block">
<a href="http://www.mailgun.com" class="btn-primary">Upgrade my account</a>
</td>
</tr>
<tr>
<td class="content-block">
Thanks for choosing Acme Inc.
</td>
</tr>
</table>
</td>
</tr>
</table>
<div class="footer">
<table width="100%">
<tr>
<td class="aligncenter content-block"><a href="http://www.mailgun.com">Unsubscribe</a> from these alerts.</td>
</tr>
</table>
</div></div>
</td>
<td></td>
</tr>
</table>
更新 - 您可以在电子邮件中使用所有 html 标签，只是不要包含任何外部相关 css 或 javascript link 或脚本标签。理想情况下，包括 css 在内的整个 html 应该在单个 HTML 字符串中。
来自报错信息：
org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1].
我不确定 Unirest 试图做什么，但它似乎试图将某些内容编码为 JSON。但是 Mailgun API 不需要 JSON 编码，您可以使用良好的旧 application/x-www-form-urlencoded 编码。查看 Unirest 文档，看看是否可以强制使用其他编码类型。
或者您可以使用 this other library (disclaimer: I am the developer) as noted in the comments of the question. The OP complains that doesn't work with complex html as mentioned here。我的意思是内容助手机制，您可以在其中使用链式方法调用（DSL 样式）构建 HTML 内容。如果您已经有了 HTML，您只需将它传递给 html() 方法调用，如评论中所述。
您的代码看起来有点像这样：
// somewhere else
Configuration configuration = new Configuration()
.domain("sub.domain.com")
.apiKey(API_KEY)
.from("name", "test@domain.com");
public static void sendSimpleMessage() {
Mail.using(configuration)
.to("myemail@gmail.com")
.subject("Great")
.html(returnEmail())
.build()
.send();
}
我在尝试通过 Unirest.post(...).queryString("html", massiveStringHere).. asJson();
并发现 "com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]"
实际上是尝试将响应解析为 JSON 的结果。将 asJson() 更改为 asString()，您将看到 Mailgun 给您的实际错误：
<html>
<head><title>414 Request-URI Too Large</title></head>
<body bgcolor="white">
<center><h1>414 Request-URI Too Large</h1></center>
<hr><center>nginx</center>
</body>
</html>
这是因为Unirest让你添加html body作为queryString，超过了Nginx配置的允许查询字符串长度。我尝试将内容更改为 url 编码形式并使用 .field("html", massiveStringHere)，但这并没有像我预期的那样工作。为什么必须在 URL 中指定 POST 的所有字段是 IMO 的设计缺陷。我还没有找到解决方法，但会尝试这里给出的建议。希望不要诉诸 MIME 路线：-/
更新：已确认 https://github.com/sargue/mailgun 是 Mailgun 集成的方式，并且不会受到显然困扰 Unirest 的 HTML 大小限制的影响。在几分钟内轻松集成。
我正在尝试获取
"html": "... entire contents of HTML page goes here ..." 在 Java 中使用 Unirest HTTP 与 MailGun API 通信。
到目前为止，我已经验证了我的域，通过 API 成功发送了一封电子邮件，并通过 Java 中的 API 成功发送了一封 HTML（基本）电子邮件]. 每当我尝试使用任何电子邮件模板时，我都无法发送电子邮件（通过 API，在 Java 中）。我试图使用此处推荐的电子邮件模板：https://github.com/mailgun/transactional-email-templates/tree/master/templates .
我发送邮件的代码与文档一致
public static JsonNode sendSimpleMessage() throws UnirestException {
HttpResponse<com.mashape.unirest.http.JsonNode> request = Unirest.post("https://api.mailgun.net/v3/sub.domain.com" + "/messages")
.basicAuth("api", API_KEY)
.queryString("from", "name <test@domain.com>")
.queryString("to", "myemail@gmail.com")
.queryString("subject", "Great")
.queryString("html", returnEmail())
.asJson();
return request.getBody();
}
public static String returnEmail() {
try {
return StreamUtils.copyToString(new ClassPathResource("email.html").getInputStream(), Charset.defaultCharset());
} catch (IOException e) {
e.printStackTrace();
}
return "<html><strong>not today</strong></html>";
}
并且 email.html 包含来自上述电子邮件 (https://github.com/mailgun/transactional-email-templates/tree/master/templates) 或任何 HTML 电子邮件的示例，因为 none 有效。
我得到的错误是：
com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1].
堆栈跟踪：
com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:143)
at com.mashape.unirest.request.BaseRequest.asJson(BaseRequest.java:68)
at com..application.ApplicationController.sendSimpleMessage(ApplicationController.java:78)
at com.application.ApplicationController.create(ApplicationController.java:61)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.HttpResponse.<init>(HttpResponse.java:106)
at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:139)
... 57 more
Caused by: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.JsonNode.<init>(JsonNode.java:51)
at com.mashape.unirest.http.HttpResponse.<init>(HttpResponse.java:95)
... 58 more
Caused by: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at org.json.JSONTokener.syntaxError(JSONTokener.java:433)
at org.json.JSONArray.<init>(JSONArray.java:105)
at org.json.JSONArray.<init>(JSONArray.java:144)
at com.mashape.unirest.http.JsonNode.<init>(JsonNode.java:48)
... 59 more
如果我只是将所有 HTML 粘贴为字符串而不是 returnEmail()，我也会遇到同样的错误。如果我在发送前转义特殊字符 and/or 缩小 HTML，我也会收到相同的错误消息。
现在我假设 Unirest 是一个 http 库，它从 queryString 键和值构建一个 JSON。虽然它似乎与 simpel html 一起工作，例如“HTML version whatever ，但它肯定不喜欢任何冗长的/'normal' html ，例如电子邮件模板。
能否请您为使用 Java API 的 html 电子邮件建议任何工作示例，或任何关于如何发送 html 并具有有效 json?
非常感谢
从您共享的 html 个文件中，使用正文中的 html，删除所有其他标签，它应该可以正常工作 post。
例如。来自文件 - https://github.com/mailgun/transactional-email-templates/blob/master/templates/alert.html
仅使用下面提到的 html。
<table class="body-wrap">
<tr>
<td></td>
<td class="container" width="600">
<div class="content">
<table class="main" width="100%" cellpadding="0" cellspacing="0">
<tr>
<td class="alert alert-warning">
Warning: You're approaching your limit. Please upgrade.
</td>
</tr>
<tr>
<td class="content-wrap">
<table width="100%" cellpadding="0" cellspacing="0">
<tr>
<td class="content-block">
You have <strong>1 free report</strong> remaining.
</td>
</tr>
<tr>
<td class="content-block">
Add your credit card now to upgrade your account to a premium plan to ensure you don't miss out on any reports.
</td>
</tr>
<tr>
<td class="content-block">
<a href="http://www.mailgun.com" class="btn-primary">Upgrade my account</a>
</td>
</tr>
<tr>
<td class="content-block">
Thanks for choosing Acme Inc.
</td>
</tr>
</table>
</td>
</tr>
</table>
<div class="footer">
<table width="100%">
<tr>
<td class="aligncenter content-block"><a href="http://www.mailgun.com">Unsubscribe</a> from these alerts.</td>
</tr>
</table>
</div></div>
</td>
<td></td>
</tr>
</table>
更新 - 您可以在电子邮件中使用所有 html 标签，只是不要包含任何外部相关 css 或 javascript link 或脚本标签。理想情况下，包括 css 在内的整个 html 应该在单个 HTML 字符串中。
来自报错信息：
org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1].
我不确定 Unirest 试图做什么，但它似乎试图将某些内容编码为 JSON。但是 Mailgun API 不需要 JSON 编码，您可以使用良好的旧 application/x-www-form-urlencoded 编码。查看 Unirest 文档，看看是否可以强制使用其他编码类型。
或者您可以使用 this other library (disclaimer: I am the developer) as noted in the comments of the question. The OP complains that doesn't work with complex html as mentioned here。我的意思是内容助手机制，您可以在其中使用链式方法调用（DSL 样式）构建 HTML 内容。如果您已经有了 HTML，您只需将它传递给 html() 方法调用，如评论中所述。
您的代码看起来有点像这样：
// somewhere else
Configuration configuration = new Configuration()
.domain("sub.domain.com")
.apiKey(API_KEY)
.from("name", "test@domain.com");
public static void sendSimpleMessage() {
Mail.using(configuration)
.to("myemail@gmail.com")
.subject("Great")
.html(returnEmail())
.build()
.send();
}
我在尝试通过 Unirest.post(...).queryString("html", massiveStringHere).. asJson();
并发现 "com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]"
实际上是尝试将响应解析为 JSON 的结果。将 asJson() 更改为 asString()，您将看到 Mailgun 给您的实际错误：
<html>
<head><title>414 Request-URI Too Large</title></head>
<body bgcolor="white">
<center><h1>414 Request-URI Too Large</h1></center>
<hr><center>nginx</center>
</body>
</html>
这是因为Unirest让你添加html body作为queryString，超过了Nginx配置的允许查询字符串长度。我尝试将内容更改为 url 编码形式并使用 .field("html", massiveStringHere)，但这并没有像我预期的那样工作。为什么必须在 URL 中指定 POST 的所有字段是 IMO 的设计缺陷。我还没有找到解决方法，但会尝试这里给出的建议。希望不要诉诸 MIME 路线：-/
更新：已确认 https://github.com/sargue/mailgun 是 Mailgun 集成的方式，并且不会受到显然困扰 Unirest 的 HTML 大小限制的影响。在几分钟内轻松集成。