如何从Java类进行SOAP Web服务调用？ [英] How to do a SOAP Web Service call from Java class?

问题描述

我对网络服务世界相对较新，而且我的研究似乎让我困惑不仅仅是启发我，我的问题是我得到了一个库（jar），我必须扩展一些web服务功能。

I'm relative new to the webservices world and my research seems to have confused me more than enlighten me, my problem is that I was given a library(jar) which I have to extend with some webservice functionality.

这个库将与其他开发人员共享，并且jar中的类将是具有调用webservice的方法的类（基本上设置类的属性，是一些业务逻辑，比如将对象存储在数据库等中，并通过这些修改发回对象）。我希望尽可能简单地调用此服务，希望这样简单，以便开发人员只需要使用该类。

This library will be shared to other developers, and among the classes in the jar will be classes that have a method which calls a webservice (that essentially sets an attribute of the class, does some business logic, like storing the object in a db, etc and sends back the object with those modifications). I want to make the call to this service as simple as possible, hopefully as simple so that the developer using the class only need to do.

Car c = new Car("Blue");
c.webmethod();

我一直在研究在服务器上使用的JAX-WS，但在我看来我不这样做需要在服务器上创建 wsimport ，在客户端上创建 wsimport ，因为我知道两者都有类，我只需要在服务器和客户端共享的类之间进行一些交互。你觉得在课堂上做网络服务和电话会有什么意义吗？

I have been studying JAX-WS to use on the server but seems to me that I don't need to create a wsimport in the server nor the wsimport on the client, since I know that both have the classes, I just need some interaction between classes shared in both the server and the client. How do you think makes sense to do the webservice and the call in the class?

推荐答案

我理解你的问题归结为如何从Java调用SOAP（JAX-WS）Web服务并获取其返回对象。在这种情况下，您有两种可能的方法：

I understand your problem boils down to how to call a SOAP (JAX-WS) web service from Java and get its returning object. In that case, you have two possible approaches:

1. 通过 wsimport生成Java类并使用它们;或


2. 创建一个SOAP客户端：
   
   

1. Generate the Java classes through wsimport and use them; or
2. Create a SOAP client that:

1. 将服务的参数序列化为XML;


2. 通过HTTP操作调用web方法;和


3. 将返回的XML响应解析回对象。

关于第一种方法（使用 wsimport ）：

About the first approach (using wsimport):

我看到你已经有了服务'（实体或其他）业务类，而且 wsimport 生成了一整套新的事实。类（有些类似于你已经拥有的类的重复）。

I see you already have the services' (entities or other) business classes, and it's a fact that the wsimport generates a whole new set of classes (that are somehow duplicates of the classes you already have).

我担心，在这种情况下，你只能：

I'm afraid, though, in this scenario, you can only either:

• 调整（编辑） wsimport 生成的代码，使其使用您的业务类（这很困难，不知何故不值得 - 记住每次WSDL更改时，您都必须重新生成并重新编写代码）;或


• 放弃并使用 wsimport 生成的类。 （在此解决方案中，您的业务代码可以将生成的类用作来自另一个架构层的服务。）

• Adapt (edit) the wsimport generated code to make it use your business classes (this is difficult and somehow not worth it - bear in mind everytime the WSDL changes, you'll have to regenerate and readapt the code); or
• Give up and use the wsimport generated classes. (In this solution, you business code could "use" the generated classes as a service from another architectural layer.)

关于第二种方法（创建自定义SOAP客户端）：

为了实现第二种方法，您必须：

In order to implement the second approach, you'll have to:

1. 拨打电话：
   
   
   
   
   • 使用SAAJ（SOAP with Attachments API for Java）框架（见下文，Java SE 1.6或更高版本附带）进行调用;或者
   
   
   • 你也可以通过 java.net.HttpUrlconnection （和一些 java.io 处理）。
   
   

1. Make the call:
   • Use the SAAJ (SOAP with Attachments API for Java) framework (see below, it's shipped with Java SE 1.6 or above) to make the calls; or
   • You can also do it through java.net.HttpUrlconnection (and some java.io handling).

• 使用OXM（对象到XML映射）框架（如JAXB）从/向对象序列化/反序列化XML


• 或者，如果必须，手动创建/解析XML（如果收到的对象与发送的对象有点不同，这可能是最好的解决方案。）

使用经典 java.net.HttpUrlConnection 创建SOAP客户端并不是那么难（但也不是那么简单），而你可以在此链接中找到一个非常好的起始代码。

Creating a SOAP client using classic java.net.HttpUrlConnection is not that hard (but not that simple either), and you can find in this link a very good starting code.

我建议您使用SAAJ框架：

I recommend you use the SAAJ framework:

SOAP with Attachments API for Java（SAAJ）主要用于deali直接在任何Web服务API的幕后发生的SOAP请求/响应消息。它允许开发人员直接发送和接收soap消息，而不是使用JAX-WS。

SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.

请参阅下面的一个工作示例（运行它！ ）使用SAAJ进行SOAP Web服务调用。它称为此网络服务。

See below a working example (run it!) of a SOAP web service call using SAAJ. It calls this web service.

import javax.xml.soap.*;

public class SOAPClientSAAJ {

    // SAAJ - SOAP Client Testing
    public static void main(String args[]) {
        /*
            The example below requests from the Web Service at:
             https://www.w3schools.com/xml/tempconvert.asmx?op=CelsiusToFahrenheit


            To call other WS, change the parameters below, which are:
             - the SOAP Endpoint URL (that is, where the service is responding from)
             - the SOAP Action

            Also change the contents of the method createSoapEnvelope() in this class. It constructs
             the inner part of the SOAP envelope that is actually sent.
         */
        String soapEndpointUrl = "https://www.w3schools.com/xml/tempconvert.asmx";
        String soapAction = "https://www.w3schools.com/xml/CelsiusToFahrenheit";

        callSoapWebService(soapEndpointUrl, soapAction);
    }

    private static void createSoapEnvelope(SOAPMessage soapMessage) throws SOAPException {
        SOAPPart soapPart = soapMessage.getSOAPPart();

        String myNamespace = "myNamespace";
        String myNamespaceURI = "https://www.w3schools.com/xml/";

        // SOAP Envelope
        SOAPEnvelope envelope = soapPart.getEnvelope();
        envelope.addNamespaceDeclaration(myNamespace, myNamespaceURI);

            /*
            Constructed SOAP Request Message:
            <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myNamespace="https://www.w3schools.com/xml/">
                <SOAP-ENV:Header/>
                <SOAP-ENV:Body>
                    <myNamespace:CelsiusToFahrenheit>
                        <myNamespace:Celsius>100</myNamespace:Celsius>
                    </myNamespace:CelsiusToFahrenheit>
                </SOAP-ENV:Body>
            </SOAP-ENV:Envelope>
            */

        // SOAP Body
        SOAPBody soapBody = envelope.getBody();
        SOAPElement soapBodyElem = soapBody.addChildElement("CelsiusToFahrenheit", myNamespace);
        SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("Celsius", myNamespace);
        soapBodyElem1.addTextNode("100");
    }

    private static void callSoapWebService(String soapEndpointUrl, String soapAction) {
        try {
            // Create SOAP Connection
            SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
            SOAPConnection soapConnection = soapConnectionFactory.createConnection();

            // Send SOAP Message to SOAP Server
            SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(soapAction), soapEndpointUrl);

            // Print the SOAP Response
            System.out.println("Response SOAP Message:");
            soapResponse.writeTo(System.out);
            System.out.println();

            soapConnection.close();
        } catch (Exception e) {
            System.err.println("\nError occurred while sending SOAP Request to Server!\nMake sure you have the correct endpoint URL and SOAPAction!\n");
            e.printStackTrace();
        }
    }

    private static SOAPMessage createSOAPRequest(String soapAction) throws Exception {
        MessageFactory messageFactory = MessageFactory.newInstance();
        SOAPMessage soapMessage = messageFactory.createMessage();

        createSoapEnvelope(soapMessage);

        MimeHeaders headers = soapMessage.getMimeHeaders();
        headers.addHeader("SOAPAction", soapAction);

        soapMessage.saveChanges();

        /* Print the request message, just for debugging purposes */
        System.out.println("Request SOAP Message:");
        soapMessage.writeTo(System.out);
        System.out.println("\n");

        return soapMessage;
    }

}

关于使用JAXB进行序列化/反序列化，很容易找到它的信息。您可以从这里开始： http://www.mkyong.com/java/jaxb -hello-world-example / 。

About using JAXB for serializing/deserializing, it is very easy to find information about it. You can start here: http://www.mkyong.com/java/jaxb-hello-world-example/.

这篇关于如何从Java类进行SOAP Web服务调用？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！