使用spring-ws开发webservice

spring是一个优雅的框架,将常用的技术粘合在一起。spring-ws相对于其他框架最大的优点是对web服务涉及技术的抽象非常的好,为webservice处理提供统一的模型,而又不限制实现时使用的技术。

发布webservice

发布webservice有以下几个步骤:
1. 编写服务接口定义,包括类型定义,服务方法定义。
2. 实现服务接口定义的方法。
3. 发布服务。
本文已一个订单服务为例

为什么契约优先

开发webservice可以定义java代码,通过框架生产wsdl/xsd内容。也可以采用契约优先方式,先定义wsdl/xsd,然后生成java代码。通过契约优先的方式有以下原因:
1. Object/XML之间的转换。对象与xml转换不能完全的匹配,xsd可以定义对象的限制,比如字符串必须是大写,而java对象没有办法定义限制。
2. java类不是可移植的类型。
3. 环形依赖。如果一个类之间相互依赖,则生成的xml会不停的嵌套。
详情可以参考《Spring Web Services Reference》

编写服务接口定义

定义数据类型,对于请求和反馈,尽量增加一个基础类,这样可以随时增加公共的内容。
xsd文件内容


<schema targetNamespace="http://www.nxmax.net/hello"
    elementFormDefault="qualified" xmlns="http://www.w3.org/2001/XMLSchema"
    xmlns:tns="http://www.nxmax.net/hello">
    <complexType name="BaseRespType" abstract="true">
        <sequence>
            <element name="success" type="boolean" minOccurs="1"
                maxOccurs="1" />
            <element name="message" type="string" minOccurs="0" />
        sequence>
    complexType>
    <complexType name="BaseReqType" abstract="true">
        <sequence>
            <element name="callerIndentifier" type="string" minOccurs="1" maxOccurs="1">element>
        sequence>
    complexType>
    <element name="CreateOrderReq">
        <complexType>
            <complexContent>
                <extension base="tns:BaseReqType">
                    <sequence>
                        <element name="GoodCode" type="string" />
                        <element name="Amount" type="int" />
                        <element name="Remarks" type="string" minOccurs="0" />
                    sequence>
                extension>
            complexContent>
        complexType>
    element>
    <element name="CreateOrderResp">
        <complexType>
            <complexContent>
                <extension base="tns:BaseRespType">
                    <sequence>
                        <element name="OrderNum" type="string" minOccurs="1"
                            maxOccurs="1">element>
                    sequence>
                extension>
            complexContent>
        complexType>
    element>

    <element name="InquireReq">
        <complexType>
            <complexContent>
                <extension base="tns:BaseReqType">
                    <sequence>
                        <element name="orderNum" type="string" minOccurs="1" maxOccurs="1">element>
                    sequence>
                extension>
            complexContent>
        complexType>element>

    <element name="InquireResp">
        <complexType>
            <complexContent>
                <extension base="tns:BaseRespType">
                    <sequence>
                        <element name="orderInfo" type="tns:OrderInfoType" minOccurs="0" maxOccurs="1">element>
                    sequence>
                extension>
            complexContent>
        complexType>
    element>

    <complexType name="OrderInfoType">
        <all>
            <element name="orderNum" type="string" minOccurs="1"
                maxOccurs="1">
            element>
            <element name="date" type="date" minOccurs="1"
                maxOccurs="1">
            element>
            <element name="time" type="time" minOccurs="1"
                maxOccurs="1">
            element>
            <element name="goodCode" type="string" minOccurs="1"
                maxOccurs="1">
            element>
            <element name="remarks" type="string" minOccurs="0" maxOccurs="1">element>
        all>
    complexType>
schema>

编写wsdl文件


<wsdl:definitions name="hello" targetNamespace="http://www.nxmax.net/hello/"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://www.nxmax.net/hello/"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:xsd1="http://www.nxmax.net/hello" xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/"
    xmlns:http="http://schemas.xmlsoap.org/wsdl/http/">
    <wsdl:types>
        <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
            <xsd:import namespace="http://www.nxmax.net/hello"
                schemaLocation="hello.xsd">
            xsd:import>
        xsd:schema>
    wsdl:types>
    <wsdl:message name="createRequest">
        <wsdl:part element="xsd1:CreateOrderReq" name="parameters" />
    wsdl:message>
    <wsdl:message name="createResponse">
        <wsdl:part element="xsd1:CreateOrderResp" name="parameters" />
    wsdl:message>
    <wsdl:message name="inquireRequest">
        <wsdl:part name="parameters" element="xsd1:InquireReq">wsdl:part>
    wsdl:message>
    <wsdl:message name="inquireResponse">
        <wsdl:part name="parameters" element="xsd1:InquireResp">wsdl:part>
    wsdl:message>
    <wsdl:portType name="Order">
        <wsdl:operation name="create">
            <wsdl:input message="tns:createRequest" />
            <wsdl:output message="tns:createResponse" />
        wsdl:operation>
        <wsdl:operation name="inquire">
            <wsdl:input message="tns:inquireRequest">wsdl:input>
            <wsdl:output message="tns:inquireResponse">wsdl:output>
        wsdl:operation>
    wsdl:portType>
    <wsdl:binding name="OrderBinding" type="tns:Order">

        <soap:binding style="document"
            transport="http://schemas.xmlsoap.org/soap/http" />
        <wsdl:operation name="create">

            <soap:operation
                soapAction="http://www.nxmax.net/hello/create" />
            <wsdl:input>

                <soap:body use="literal" />
            wsdl:input>
            <wsdl:output>

                <soap:body use="literal" />
            wsdl:output>
        wsdl:operation>
        <wsdl:operation name="inquire">
            <soap:operation
                soapAction="http://www.nxmax.net/hello/inquire" />
            <wsdl:input>
                <soap:body use="literal" />
            wsdl:input>
            <wsdl:output>
                <soap:body use="literal" />
            wsdl:output>
        wsdl:operation>
    wsdl:binding>
    <wsdl:service name="OrderService">
        <wsdl:port binding="tns:OrderBinding" name="OrderPort">
            <soap:address location="http://www.example.org/" />
        wsdl:port>
    wsdl:service>
wsdl:definitions>

spring处理webservice请求原理

一个webservice请求如下,

POST http://localhost:8081/sws/ HTTP/1.1
Content-Type: text/xml;charset=UTF-8
SOAPAction: "http://www.nxmax.net/hello/create"
User-Agent: Jakarta Commons-HttpClient/3.1
Host: localhost:8081
Content-Length: 467

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:hel="http://www.nxmax.net/hello">
   <soapenv:Header/>
   <soapenv:Body>
      <hel:CreateOrderReq>
         <hel:callerIndentifier>ewewehel:callerIndentifier>
         <hel:GoodCode>2323hel:GoodCode>
         <hel:Amount>3hel:Amount>
         <hel:Remarks>2323hel:Remarks>
         
      hel:CreateOrderReq>
   soapenv:Body>
soapenv:Envelope>

spring接受到请求后通过EndpointMapping获取分发目标。默认spring支持3种分发方式:
1. 通过xml携带的内容确定。soapenv:Body保护了本次请求的内容。通过@PayloadRoot指明,如@PayloadRoot(namespace = “http://www.nxmax.net/hello“, localPart = “CreateOrderReq”)
2. 通过http头中的SOAPAction确定。通过@SoapAction指明,如@SoapAction(“http://www.nxmax.net/hello/create“)
3. 通过WS-Addressing中的Action确定。通过@Action指明,如@Action(“http://globalplatform.org/globaleligibilityinfo/GlobalEligibilityInfo/CheckGlobalEligibilityRequest“)
spring-ws提供灵活处理输入输出的方式,可以手动处理xml,可以通过jaxb将xml转换为对象之后再由应用处理。支持的类型非常广泛,具体可以参考《Spring Web Services Reference》的5.4 Endpoints。

手工处理xml内容

手工处理xml内容需要使用 @PayloadRoot修饰方法,方法的参数类型可以使用org.w3c.dom.Element,示例如下:

package net.nxmax.sws.impl;

import java.io.ByteArrayInputStream;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.ws.server.endpoint.annotation.Endpoint;
import org.springframework.ws.server.endpoint.annotation.PayloadRoot;
import org.springframework.ws.server.endpoint.annotation.RequestPayload;
import org.springframework.ws.server.endpoint.annotation.ResponsePayload;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

// 指定是一个ws入口
@Endpoint
public class XmlEndpoint {
    private static final String NAMESPACE_URI = "http://www.nxmax.net/hello";

    /** Logger */
    private static final Logger LOG = LoggerFactory
            .getLogger(XmlEndpoint.class);
    private TransformerFactory transFactory = TransformerFactory.newInstance();
    private DocumentBuilderFactory cocumentBuilderFactory = DocumentBuilderFactory
            .newInstance();

    // 使用内容作为分发标识
    // @ResponsePayload 指明返回值需要转换
    // @RequestPayload 指明是输入的参数
    @PayloadRoot(namespace = NAMESPACE_URI, localPart = "CreateOrderReq")
    @ResponsePayload
    public Element create(@RequestPayload Element req) throws Exception {
        LOG.info("REQ XML:{}", e2s(req));
        Element rt = getReturn();
        LOG.info("RESP XML:{}", e2s(rt));
        return rt;
    }

    private Object e2s(Element req) throws Exception {
        Transformer transformer = transFactory.newTransformer();
        StringWriter buffer = new StringWriter();
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        transformer.transform(new DOMSource(req), new StreamResult(buffer));
        String str = buffer.toString();
        return str;
    }

    private Element getReturn() throws Exception {
        StringBuilder sb = new StringBuilder();
        sb.append("");
        sb.append("true");
        sb.append("3232323");
        sb.append("2222222222");
        sb.append("");

        Document x = cocumentBuilderFactory.newDocumentBuilder().parse(
                new ByteArrayInputStream(sb.toString().getBytes()));
        return x.getDocumentElement();
    }
}

函数的参数可以可以包含其他内容,比如MessageContext。比如方法可以定义为

public Element create(@RequestPayload Element req, MessageContext context,
            SoapMessage message) throws Exception 

MessageContext,SoapMessage是默认启用的,不需要@RequestPayload修饰。

将定义转换为java代码

现在还在使用xml处理webservice,太out了吧。没问题,我们来使用java的标准工具。
java有自带的工具将wsdl/xsd转换为java代码。导入wsdl的是wsimport,导入xsd的是xjc。分别使用以下命令导入。
wsimport -p net.nxmax.sws.def -d ..\java -Xnocompile -verbose -target 2.2 hello.wsdl
xjc -p net.nxmax.sws.def -d ..\java -verbose -no-header hello.xsd
对于spring的调用,xjc就足够了,因为操作可以通过请求确定,完整的wsdl定义就不需要了。
下面是方法的定义

    // 下面是使用jaxb,使用soapation的方式
    protected ObjectFactory factory = new ObjectFactory();

    @SoapAction("http://www.nxmax.net/hello/create")
    @ResponsePayload
    public CreateOrderResp create(@RequestPayload CreateOrderReq req) {
        return factory.createCreateOrderResp();
    }

    @SoapAction("http://www.nxmax.net/hello/inquire")
    @ResponsePayload
    public InquireResp inquire(@RequestPayload InquireReq req) {
        return factory.createInquireResp();
    }

这样就非常方便了。

引用

spring可以使用wsimport生成的定义,但是在spring-ws中使用org.springframework.ws.client.core.WebServiceTemplate功能更强大,灵活。测试代码如下:


<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:ws="http://www.springframework.org/schema/web-services" xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/web-services http://www.springframework.org/schema/web-services/web-services.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <bean id="messageFactory" class="org.springframework.ws.soap.saaj.SaajSoapMessageFactory" />

    
    <bean id="jaxb" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
        <property name="contextPath" value="net.nxmax.sws.def">property>
    bean>

    
    <bean id="webServiceTemplate" class="org.springframework.ws.client.core.WebServiceTemplate"
        p:defaultUri="http://localhost:8081/sws/" p:marshaller-ref="jaxb"
        p:unmarshaller-ref="jaxb">
        <constructor-arg ref="messageFactory" />
    bean>

beans>
package net.nxmax.sws.client;

import net.nxmax.sws.def.CreateOrderReq;
import net.nxmax.sws.def.CreateOrderResp;
import net.nxmax.sws.def.ObjectFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.GenericXmlApplicationContext;
import org.springframework.ws.client.core.WebServiceMessageCallback;
import org.springframework.ws.client.core.WebServiceTemplate;
import org.springframework.ws.soap.client.core.SoapActionCallback;

public class SwsClient {

    /** Logger */
    private static final Logger LOG = LoggerFactory.getLogger(SwsClient.class);

    public static void main(String[] args) {
        new SwsClient().go();
    }

    private void go() {
        ObjectFactory factory = new ObjectFactory();
        ConfigurableApplicationContext ctx = new GenericXmlApplicationContext(
                "classpath:/client.xml");
        WebServiceTemplate template = ctx.getBean(WebServiceTemplate.class);

        // 指定soapation,与wsdl中的定义一致。如果
        WebServiceMessageCallback callback = new SoapActionCallback(
                "http://www.nxmax.net/hello/create");
        CreateOrderReq req = factory.createCreateOrderReq();

        CreateOrderResp resp = (CreateOrderResp) template
                .marshalSendAndReceive(req, callback);
        LOG.info("Result:{}", resp.isSuccess());
        ctx.close();
    }

}

示例代码

你可能感兴趣的:(java,spring)