一、背景说明

在已有的项目中，已经获取到了Graph的AccessToken并保存在内存里面。所以不希望再通过client secret或者certificate去创建GraphServiceClient对象。希望使用现有的token字符串来创建初始化创建GraphServiceClient从而来实现Graph其他API功能。

二、具体实现

2.1 需要Java Graph SDK依赖 加入到pom.xml文件内

 <!-- Microsoft Graph SDK for Java --><dependency><groupId>com.microsoft.graph</groupId><artifactId>microsoft-graph</artifactId><version>[5.0,)</version></dependency><!-- Azure AD Authentication SDK for Java --><dependency><groupId>com.azure</groupId><artifactId>azure-identity</artifactId><version>[1.3,)</version></dependency>

2.2 代码片段

  public static GraphServiceClient initGraphServiceClient() {IAuthenticationProvider authProvider = new IAuthenticationProvider() {@Overridepublic CompletableFuture<String> getAuthorizationTokenAsync(URL requestUrl) {CompletableFuture<String> future = new CompletableFuture<>();future.complete(Your_AccessToken);return future;}};return GraphServiceClient.builder().authenticationProvider(authProvider).buildClient();}

三、测试

下面代码是实现调用创建GraphServiceClient，调用graph api发送带附件的邮件。

	public static String sendMail() {try {String mfrom = "xxxx@outlook.com";String to = "xxxx@outlook.com";GraphServiceClient<Request> graphClient = initGraphServiceClient();Message message = new Message();message.subject = "Meet for lunch?";ItemBody body = new ItemBody();body.contentType = BodyType.TEXT;body.content = "The new cafeteria is open.";message.body = body;LinkedList<Recipient> toRecipientsList = new LinkedList<Recipient>();Recipient toRecipients = new Recipient();EmailAddress emailAddress = new EmailAddress();emailAddress.address = to;toRecipients.emailAddress = emailAddress;toRecipientsList.add(toRecipients);message.toRecipients = toRecipientsList;// 构建附件LinkedList<Attachment> attachmentsList = new LinkedList<Attachment>();FileAttachment attachments = new FileAttachment();attachments.name = "hello word.txt";attachments.oDataType = "#microsoft.graph.fileAttachment";attachments.contentType = "text/plain";attachments.contentBytes = Base64.getDecoder().decode("SGVsbG8gV29ybGQh");attachmentsList.add(attachments);AttachmentCollectionResponse attachmentCollectionResponse = new AttachmentCollectionResponse();attachmentCollectionResponse.value = attachmentsList;AttachmentCollectionPage attachmentCollectionPage = new AttachmentCollectionPage(attachmentCollectionResponse, null);message.attachments = attachmentCollectionPage;// 以指定用户邮箱发送邮件graphClient.users(mfrom).sendMail(UserSendMailParameterSet.newBuilder().withMessage(message).withSaveToSentItems(true).build()).buildRequest().post();log.info("send email success");return "success";} catch (Exception e) {e.printStackTrace();log.error("send email error : {}", e.getMessage());return e.getMessage();}}