Learn from the application of Jakarta SOAP WITH Attachments API in the Java library

Learn from the application of Jakarta SOAP WITH Attachments API in the Java library Introduction: Jakarta SOAP With Attachments API (referred to as SAAJ) is a standard API on the Java platform for processing SOAP messages with attachments.Through SAAJ, developers can easily build, send and receive SOAP messages, and support the news of carrying attachments. Application background: With the popularity of Web services, SOAP (Simple Object Access Protocol), as a general protocol, is widely used in communication between different platforms.Sometimes, some binary files or a lot of data need to be passed in SOAP messages. At this time, attachments need to be used to carry this information.SAAJ provides a standard method to process this SOAP message with attachments. The main features of Saaj include: 1. Construct SOAP message: Use SAAJ, you can build SOAP messages in Java, and you can set the namespace, head, text, and attachment.This enables developers to generate SOAP messages directly in a programmatic manner. 2. Send SOAP message: Saaj provides the function of sending SOAP messages. You can send the message to the server based on a standard HTTP protocol.Developers can specify information such as SOAP messages to be sent and URLs of target services. 3. Receive SOAP messages: SAAJ can analyze the receiving SOAP messages and provide APIs to analyze the various parts of SOAP messages, including head, text, and accessories.Through SAAJ, developers can easily extract information in SOAP messages. 4. Treatment of SOAP Annex: Saaj provides support for attachments in SOAP messages.Developers can add attachments to the message through SAAJ, and can extract attachments from the received SOAP messages. Java code example: 1. Build and send SOAP messages: // Create soap messages SOAPMessage soapMessage = MessageFactory.newInstance().createMessage(); // Set the naming space SOAPPart soapPart = soapMessage.getSOAPPart(); SOAPEnvelope envelope = soapPart.getEnvelope(); envelope.addNamespaceDeclaration("ns", "http://example.com/namespace"); // Set the text SOAPBody soapBody = envelope.getBody(); SOAPElement operationElement = soapBody.addChildElement("operation", "ns"); operationElement.addTextNode("Some operation data"); // Create HTTP connection URL url = new URL("http://example.com/soap-endpoint"); URLConnection connection = url.openConnection(); HttpURLConnection httpConnection = (HttpURLConnection) connection; // Set the connection attribute httpConnection.setRequestMethod("POST"); httpConnection.setDoOutput(true); httpConnection.setRequestProperty("Content-Type", "text/xml"); // Send SOAP messages to the server soapMessage.writeTo(httpConnection.getOutputStream()); // Get the response of the server InputStream responseStream = httpConnection.getInputStream(); 2. Receive and process SOAP messages: // Create soap messages MessageFactory messageFactory = MessageFactory.newInstance(); SOAPMessage soapMessage = messageFactory.createMessage(null, inputStream); // Analyze the head of the soap message SOAPPart soapPart = soapMessage.getSOAPPart(); SOAPEnvelope envelope = soapPart.getEnvelope(); SOAPHeader soapHeader = envelope.getHeader(); // Analyze the text of the soap message SOAPBody soapBody = envelope.getBody(); SOAPElement operationElement = soapBody.getElementByName(new QName("http://example.com/namespace", "operation")); // Extract the attachment in soap messages MimeHeaders mimeHeaders = soapMessage.getMimeHeaders(); AttachmentPart attachment = soapMessage.getAttachment("attachment-1"); // Process data and attachments in SOAP messages String operationData = operationElement.getTextContent(); InputStream attachmentData = attachment.getRawContentBytes(); Summarize: Jakarta SOAP with Attachments API (Saaj) provides a standard method for processing SOAP messages with attachments.Developers can use SAAJ to build, send and receive SOAP messages, and support processing attachments.Through SAAJ, we can easily implement functions related to Web services in the Java library.Use SAAJ can handle SOAP messages more flexibly and can process complex message transmission with attachments.