如何在 Java 中使用 GMail API 从电子邮件正文中获取 HTML(表格)

Question

我必须阅读 HTML 中 table 开发的一些确认邮件。

我正在使用 GMail API 和 Java 编程语言。

我正在进行注册过程的自动化，因此我必须将 link 发送到确认电子邮件，然后通过 Selenium 测试单击该确认按钮。

作为回应，我收到的电子邮件只有文本，例如，如果我向我的邮件发送一些随机文本，我可以得到该文本作为回应，但是，对于 table 种电子邮件，我收到正文为空的消息。

这是该电子邮件的 HTML 代码。

电子邮件图片：Image of email

<!doctype html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml">
<head>
<title>Test</title>
<meta content="light only" name="color-scheme" />
<meta name="”x-apple-disable-message-reformatting”" />
<style></style>
</head>
<body class="full-width" data-gr-ext-installed="" data-new-gr-c-s-check-loaded="14.997.0" style="max-width: 600px;width: 100%;background: #333333; margin: 0 auto;">
<div class="full-width" style="width: 100%;padding: 1em 0;"><!--[if mso | IE]>
</td></tr></table>
<![endif]--><!--[if mso | IE]>
<table class="full-width" border="0" cellpadding="0" cellspacing="0" width="600" align="center" style="width: 100%;">
<tr style="    width: 100%;">
<td style="line-height:0px;font-size:0px;mso-line-height-rule:exactly;">
<![endif]-->
<div class="full-width" style="    width: 100%;margin:0 auto;max-width:600px;background:#333333;">
<table align="center" border="0" cellpadding="0" cellspacing="0" class="full-width" style="font-size:0px;width:100%;background:#1b2940;">
<tbody class="full-width">
<tr class="full-width">
<td class="full-width" style="text-align:center;vertical-align:top;font-size:0px;padding:0px;"><!--[if mso | IE]>
<table class="full-width" border="0" cellpadding="0" cellspacing="0">
<tr class="full-width">
<td class="full-width" style="vertical-align:middle;width:600px;">
<![endif]-->
<div aria-labelledby="mj-column-per-100" class="full-width" style="vertical-align:middle;display:inline-block;font-size:13px;text-align:left;width:100%;">
<table border="0" cellpadding="0" cellspacing="0" class="full-width" style="vertical-align:middle;" width="100%">
<tbody class="full-width">
<tr>
<td align="center" style="word-break:break-word;font-size:0px;padding:0px;">
<table align="center" border="0" cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-spacing:0px;">
<tbody><!--                                                                                
<tr>--><!--                                                                                    <td style="width:600px;">--><!--                                                                                        <a href="https://www.24bettle.com/?utm_source=system-email&amp;utm_medium=Image"--><!--                                                                                           target="_blank" >--><!--                                                                                            <img alt="24Bettle Logo"--><!--                                                                                                 src="http://24bettle.com/images/email_images/button-gradient-pic.png"--><!--                                                                                                 style="outline: none; text-decoration: none; clear: both; border: 0px; max-width: 640px; width: 600px; height: 122px; "--><!--                                                                                                 title=""/>--><!--                                                                                        </a>--><!--                                                                                    </td>--><!--                                                                                </tr>-->
<tr>
<td style="width:650px"><img class="first-banner" src="https://24bettle.com/images/banners/24header-image-2.png" style="outline: none; text-decoration: none; clear: both; border: 0px; max-width: 600px; width: 100%;" /></td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td align="center" style="word-break:break-word;font-size:0px;padding:0px;">&nbsp;</td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]--></td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]--><!--[if mso | IE]>
<table border="0" cellpadding="0" cellspacing="0" width="600" align="center" style="width:600px;">
<tr>
<td style="line-height:0px;font-size:0px;mso-line-height-rule:exactly;">
<![endif]-->

<div class="full-width" style="    width: 100%;margin:0 auto;max-width:600px;background:#fff;">
<table border="0" cellpadding="0" cellspacing="0" class="full-width" style="padding: 2em 2em;vertical-align:middle;" width="100%">
<tbody class="full-width">
<tr>
<td align="left" style="word-break:break-word;font-size:0px;padding:0px;">
<div style="cursor:auto;color:#000000;font-family:Verdana, sans-serif;font-size:20px;line-height:20px;">
<p style="font-size: 20px; margin: 0px 0px 15px; color: rgb(76, 76, 76); text-align: center;">Hello {username},</p>
</div>
</td>
</tr>
<tr class="full-width">
<td align="left" style="word-break:break-word;font-size:0px;padding:0px;">
<div style="cursor:auto;color:#000000;font-family:Verdana, sans-serif;font-size:14px;line-height:20px;">
<table border="0" cellpadding="0" cellspacing="0" style="font-size: 13px; background-color: rgb(255, 255, 255); vertical-align: middle;" width="100%">
<tbody>
<tr>
<td align="left" style="word-break: break-word; font-size: 0px; padding: 0px;">
<div style="cursor: auto; font-family: Verdana, sans-serif; font-size: 14px; line-height: 20px;">
<table border="0" cellpadding="0" cellspacing="0" style="font-family: Verdana, sans-serif; font-size: 13px; background-color: rgb(255, 255, 255); vertical-align: middle;" width="100%">
<tbody>
<tr>
<td align="left" style="word-break: break-word; font-size: 0px; padding: 0px;">
<div style="cursor: auto; font-size: 14px; line-height: 20px;">
<p><span style="font-family: verdana, geneva, sans-serif;"><span style="color:#333333;">Hit the link to confirm your shiny, new account and enter <strong>24Bettle </strong>- a new dimension of awesome!</span></span></p>
</div>
</td>
</tr>
</tbody>
</table>
</div>
</td>
</tr>
</tbody>
</table>
</div>
</td>
</tr>
<tr>
<td align="center" style="word-break:break-word;font-size:0px;padding:10px 25px;">
<table align="center" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr><!--                                            style="border: 3px solid #4A8FFF;box-shadow: 0px 5px 10px 0px rgba(85,108,108,1);display:inline-block;text-decoration:none;color:white;font-family:Verdana, sans-serif;font-size:22px;text-shadow: 0px 2px 0px #000000;line-height: 20px;font-weight:900;margin:0px; padding:22px 23px; background: transparent linear-gradient(180deg, RGB(118, 191, 254) 44%, #1A3380 97%) 0% 0% no-repeat padding-box; no-repeat:padding-box;border-radius: 35px"-->
<td align="center" bgcolor="" style="border-radius:6px;color:white;cursor:auto;background: url(http://24bettle.com/images/email_images/button-gradient-pic.png);background-size: 100% 100%;" valign="middle"><a href="{register_confirmation_url}" id="button" style="background-color: #4587F1;background-size: 100% 100%;background-repeat: no-repeat; background-size: cover;box-shadow: 0px 5px 10px 0px rgba(85,108,108,0.4);display:inline-block;text-decoration:none;color:white;font-size:22px;line-height: 20px;font-weight:700;margin:0px;    padding: 22px 35px;border-radius: 35px;font-family: 'Oswald', sans-serif; " target="_blank">CONFIRM!</a></td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td align="center" style="word-break:break-word;font-size:0px;padding:0px;">
<div style="cursor:auto;color:#000000;font-family:Verdana, sans-serif;font-size:14px;line-height:14px;">
<div style="text-align: -webkit-center; background-color: rgb(255, 255, 255); cursor: auto; font-family: Verdana, sans-serif; font-size: 14px; line-height: 14px;">&nbsp;</div>
</div>
</td>
</tr>
</tbody>
</table>
</div>

<div class="full-width" style="margin:0 auto;max-width:600px;">
<table align="center" border="0" cellpadding="0" cellspacing="0" class="full-width" style="font-size:0px;width:100%;background:#333333;">
<tbody class="full-width">
<tr>
<td style="text-align:center;vertical-align:top;font-size:0px;padding:0px;">
<div aria-labelledby="mj-column-per-100" class="mj-column-per-100" style="background-color: #333333;vertical-align:middle;display:inline-block;font-size:13px;text-align:center;width:100%;">
<table border="0" cellpadding="0" cellspacing="0" style="vertical-align:middle;" width="100%">
<tbody style="background: #141E30; ">
<tr>
<td align="center" style="word-break:break-word;font-size:0px;padding: 10px 0 0 0;background-color: #333333">
<div style="cursor:auto;color:#CCCCCC;font-family:Verdana, sans-serif;line-height:22px;">
<p style="padding: 0 1em;font-family: 'Segoe UI',sans-serif;font-size: 14px; margin: 0; color: #CCCCCC;text-align: -webkit-center;">&nbsp;</p>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]--></td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]--><!--[if mso | IE]>
<table class="full-width" border="0" cellpadding="0" cellspacing="0" width="600" align="center" style="width:600px;">
<tr>
<td style="line-height:0px;font-size:0px;mso-line-height-rule:exactly;">
<![endif]-->

<div class="full-width" style="margin:0 auto;max-width:600px;background:#fff;">
<table align="center" border="0" cellpadding="0" cellspacing="0" class="full-width" style="font-size:0px;width:100%;background:#fff;">
<tbody>
<tr>
<td style="text-align:center;vertical-align:top;font-size:0px;padding:0px;"><!--[if mso | IE]>
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td style="vertical-align:middle;width:300px;">
<![endif]--><!--[if mso | IE]>
</td>
<td style="vertical-align:middle;width:300px;">
<![endif]--><!--[if mso | IE]>
</td></tr></table>
<![endif]--></td>
</tr>
</tbody>
</table>
</div>
<!--[if mso | IE]>
</td></tr></table>
<![endif]--></div>
</body>
</html>

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.repackaged.org.apache.commons.codec.binary.Base64;
import com.google.api.client.repackaged.org.apache.commons.codec.binary.StringUtils;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.Gmail.Users;
import com.google.api.services.gmail.Gmail.Users.Messages;
import com.google.api.services.gmail.Gmail.Users.Messages.Get;
import com.google.api.services.gmail.GmailScopes;
import com.google.api.services.gmail.model.Label;
import com.google.api.services.gmail.model.ListLabelsResponse;
import com.google.api.services.gmail.model.ListMessagesResponse;
import com.google.api.services.gmail.model.Message;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;

public class GmailQuickstart {

private static final String APPLICATION_NAME = "Gmail API Java Quickstart";

private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

private static final String TOKENS_DIRECTORY_PATH = "tokens";

/**
* Global instance of the scopes required by this quickstart.
* If modifying these scopes, delete your previously saved tokens/ folder.
*/

private static final List<String> SCOPES = Collections.singletonList(GmailScopes.GMAIL_LABELS);

private static final String CREDENTIALS_FILE_PATH = "/credentials.json";

/**
* Creates an authorized Credential object.
* @param HTTP_TRANSPORT The network HTTP Transport.
* @return An authorized Credential object.
* @throws IOException If the credentials.json file cannot be found.
*/

private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {

// Load client secrets.

InputStream in = GmailQuickstart.class.getResourceAsStream(CREDENTIALS_FILE_PATH);

if (in == null) {
throw new FileNotFoundException("Resource not found: " + CREDENTIALS_FILE_PATH);
}

GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

// Build flow and trigger user authorization request.

GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
.setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))

.setAccessType("offline")
.build();

LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}

public static void main(String... args) throws IOException, 

// Build a new authorized API client service.

final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();

Gmail service = new Gmail.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
.setApplicationName(APPLICATION_NAME)

.build();

// Print the labels in the user's account.

String user = "me";

ListLabelsResponse listResponse = service.users().labels().list(user).execute();
List<Label> labels = listResponse.getLabels();

if (labels.isEmpty()) {

System.out.println("No labels found.");

} else {

System.out.println("Labels:");

for (Label label: labels) {

System.out.printf("- %s\n", label.getName());

}
}

// Access Gmail inbox

Gmail.Users.Messages.List request = service.users().messages().list(user).setQ("from: " + "helpdesk@b-bets.com");

ListMessagesResponse messagesResponse = request.execute();

request.setPageToken(messagesResponse.getNextPageToken());

// Get ID of the email you are looking for

Gmail.Users.Messages.List request = service.users().messages().list(user).setQ("from: " + "support1@24bettle.com");

String messageId = messagesResponse.getMessages().get(0).getId();

Message message = service.users().messages().get(user, messageId).execute();

// Print email body

String emailBody = StringUtils
.newStringUtf8(Base64.decodeBase64(message.getPayload().getParts().get(0).getBody().getData()));

System.out.println("Email body : " + emailBody);    
}
}

Answer 1

问题：

您要查找的 HTML table 在邮件第一部分的子部分中。

解释：

您从 Try this API 获得的响应具有以下大致形状（不包括不相关的字段）：

{
  "payload": { 
    "body": { "size": 0 }, 
    "parts": [ 
      { 
        "partId": "0", 
        "body": { "size": 0 }, 
        "parts": [ 
          { 
            "partId": "0.0",
            // Other fields
          }, 
          { 
            "partId": "0.1", 
            "mimeType": "text/html",
            "body": { 
              "size": 14024,
              "data": "BASE64_ENCODED_STRING"  // HTML table
            },
            // Other fields
          }
        ] 
      }, 
      { 
        "partId": "1", 
        // Other fields
      } 
    ] 
  }, 
  // Other fields
}

如果你看这个，很明显你要找的内容在第一部分，但是这部分本身包含几个子部分。这些部分中的第二部分包含所需的内容。

解决方案：

您应该能够通过以下方式从该部分检索数据：

message.getPayload().getParts().get(0).getParts().get(1).getBody().getData();

因此，替换为：

String emailBody = StringUtils
.newStringUtf8(Base64.decodeBase64(message.getPayload().getParts().get(0).getBody().getData()));

有了这个：

String emailBody = StringUtils
.newStringUtf8(Base64.decodeBase64(message.getPayload().getParts().get(0).getParts().get(1).getBody().getData()));

参考：

MessagePart

如何在 Java 中使用 GMail API 从电子邮件正文中获取 HTML(表格)

How to get HTML(tables) from email body using GMail API in Java

java

selenium

gmail-api

问题：

解释：

解决方案：

参考：