[七日打卡]大多数人忽略了的Spring官方项目，Spring Web Services

1、什么是Spring Web Service？

首先，不知道Web service的小伙伴，还需要，去了解下Web service 的相关知识再来看这篇文章。本文基于官方文档，作为基础。

Spring Web Services（Spring-WS）是Spring社区的产品，致力于创建文档驱动的Web服务。Spring Web Services旨在促进约定优先SOAP服务的开发，从而允许使用多种处理XML有效负载的方式之一来创建灵活的Web服务。该产品基于Spring本身，这意味着您可以将诸如依赖项注入之类的Spring概念用作Web服务的组成部分。

人们使用Spring-WS的原因有很多，但是大多数人在找到了遵循Web服务最佳实践所缺乏的替代SOAP堆栈之后才开始使用它。Spring-WS使最佳实践变得容易。这包括诸如WS-I基本概要文件，合同优先开发之类的实践，以及合同与实施之间的松散耦合。

如果你们项目里，还在使用Web Service 作为服务发布，那么它将是最佳实践。

2、为什么Spring-WS要用约定优先开发

众所周知，创建Web服务时，有两种开发样式：（约定滞后）Contract Last和（约定优先）Contract First。当使用Contract Last方法时，将从Java代码开始，然后从中生成Web服务契约（WSDL）。当使用契约优先时，首先要使用WSDL契约，然后使用Java来实现所述契约。 什么意思呢，也就是WSDL的诞生的问题，如何产生。

Spring-WS仅支持契约优先的开发风格。

原因总结来看有以下几点：

可以支持更复杂的对象定义，java有局限

程序更加健壮

性能更优越，Java转Xml相较而言，差一点

重用性好

扩展性强，采用配置文件，改动小

3、采用Springboot + Spring-WS实现一个简单应用

应用场景描述：

公司人事部门，完成员工对于假期的请求。员工发起，假期请求。填写起始日期时间，姓名等信息，公司完成确认。

搭建一个Springboot应用

pom文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <jaxen.version>1.1.4</jaxen.version>
        <jdom.version>2.0.1</jdom.version>
        <joda-time.version>2.10.6</joda-time.version>
        <log4j.version>1.2.16</log4j.version>
        <sourcesDir>${project.basedir}/target/generated-sources/axis</sourcesDir>
        <classesDir>${project.basedir}/target/classes</classesDir>
        <wsdl>${project.basedir}/../airline.wsdl</wsdl>
        <wsdl4j.version>1.6.1</wsdl4j.version>
        <xmlschema.version>2.1.0</xmlschema.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web-services</artifactId>
        </dependency>

        <dependency>
            <groupId>org.jdom</groupId>
            <artifactId>jdom</artifactId>
            <version>${jdom.version}</version>
        </dependency>

        <dependency>
            <groupId>jaxen</groupId>
            <artifactId>jaxen</artifactId>
            <version>${jaxen.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.ws.xmlschema</groupId>
            <artifactId>xmlschema-core</artifactId>
            <version>${xmlschema.version}</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>wsdl4j</groupId>
            <artifactId>wsdl4j</artifactId>
            <version>${wsdl4j.version}</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.ws</groupId>
            <artifactId>spring-ws-support</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jaxb2-maven-plugin</artifactId>
                <version>2.5.0</version>
                <executions>
                    <execution>
                        <id>xjc</id>
                        <goals>
                            <goal>xjc</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <sources>${project.basedir}/src/main/resources/hr.xsd</sources>
                    <packageName>com.example.demo.schema</packageName>
                    <target>2.1</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>build-helper-maven-plugin</artifactId>
                <version>1.1</version>
                <executions>
                    <execution>
                        <id>add-source</id>
                        <phase>process-sources</phase>
                        <goals>
                            <goal>add-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>target/generated-sources/xjc</source>
                            </sources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>


        </plugins>

    </build>

</project>

采用约定优先开发风格，完成对象的定义

xsd文件

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:hr="http://mycompany.com/hr/schemas"
           elementFormDefault="qualified"
           targetNamespace="http://mycompany.com/hr/schemas">
    <xs:element name="HolidayRequest">
        <xs:complexType>
            <xs:all>
                <xs:element name="Holiday" type="hr:HolidayType"/>
                <xs:element name="Employee" type="hr:EmployeeType"/>
            </xs:all>
        </xs:complexType>
    </xs:element>
    <xs:complexType name="HolidayType">
        <xs:sequence>
            <xs:element name="StartDate" type="xs:date"/>
            <xs:element name="EndDate" type="xs:date"/>
        </xs:sequence>
    </xs:complexType>
    <xs:complexType name="EmployeeType">
        <xs:sequence>
            <xs:element name="Number" type="xs:integer"/>
            <xs:element name="FirstName" type="xs:string"/>
            <xs:element name="LastName" type="xs:string"/>
        </xs:sequence>
    </xs:complexType>
</xs:schema>

应用配置文件

application.properties

server.port=8848
logging.level.web=DEBUG
spring.webservices.path=/webservices
spring.webservices.servlet.init.transformWsdlLocations=true

Endpoint

开发WebService实现Endpoint，HolidayEndpoint

package com.example.demo.endpoint;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import com.example.demo.service.HumanResourceService;
import org.jdom2.Element;
import org.jdom2.Namespace;
import org.jdom2.filter.Filters;
import org.jdom2.xpath.XPathExpression;
import org.jdom2.xpath.XPathFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.ws.server.endpoint.annotation.Endpoint;
import org.springframework.ws.server.endpoint.annotation.PayloadRoot;
import org.springframework.ws.server.endpoint.annotation.RequestPayload;

/**
 * @author 小隐乐乐
 * @since  2021/1/14 22:44
 */
@Endpoint
public class HolidayEndpoint {

    private static final String NAMESPACE_URI = "http://mycompany.com/hr/schemas";

    private XPathExpression<Element> startDateExpression;

    private XPathExpression<Element> endDateExpression;

    private XPathExpression<Element> firstNameExpression;

    private XPathExpression<Element> lastNameExpression;

    private HumanResourceService humanResourceService;

    @Autowired
    public HolidayEndpoint(HumanResourceService humanResourceService) {

        this.humanResourceService = humanResourceService;
        Namespace namespace = Namespace.getNamespace("hr", NAMESPACE_URI);
        XPathFactory xPathFactory = XPathFactory.instance();
        startDateExpression = xPathFactory.compile("//hr:StartDate", Filters.element(), null, namespace);
        endDateExpression = xPathFactory.compile("//hr:EndDate", Filters.element(), null, namespace);
        firstNameExpression = xPathFactory.compile("//hr:FirstName", Filters.element(), null, namespace);
        lastNameExpression = xPathFactory.compile("//hr:LastName", Filters.element(), null, namespace);
    }

    @PayloadRoot(namespace = NAMESPACE_URI, localPart = "HolidayRequest")
    public void handleHolidayRequest(@RequestPayload Element holidayRequest) throws Exception {

        Date startDate = parseDate(startDateExpression, holidayRequest);
        Date endDate = parseDate(endDateExpression, holidayRequest);
        String name = firstNameExpression.evaluateFirst(holidayRequest).getText() + " "
                + lastNameExpression.evaluateFirst(holidayRequest).getText();

        humanResourceService.bookHoliday(startDate, endDate, name);
    }

    private Date parseDate(XPathExpression<Element> expression, Element element) throws ParseException {

        Element result = expression.evaluateFirst(element);

        if (result != null) {
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            return dateFormat.parse(result.getText());
        } else {
            throw new IllegalArgumentException("Could not evaluate [" + expression + "] on [" + element + "]");
        }
    }

}

实现服务

服务接口

package com.example.demo.service;

import java.util.Date;

/**
 * @author 小隐乐乐
 * @since  2021/1/14 23:00
 */
public interface HumanResourceService {
    /**
     * 请假.
     *
     * @param startDate 假期开始时间
     * @param endDate   假期结束时间
     * @param name      请假人
     */
    void bookHoliday(Date startDate, Date endDate, String name);
}

服务接口实现

package com.example.demo.service.impl;

import com.example.demo.service.HumanResourceService;
import org.springframework.stereotype.Service;

import java.util.Date;

/**
 * @author 小隐乐乐
 * @since  2021/1/14 23:02
 */
@Service
public class HumanResourceServiceImpl implements HumanResourceService {

    @Override
    public void bookHoliday(Date startDate, Date endDate, String name) {
        System.out.println("Booking holiday for [" + startDate + "-" + endDate + "] for [" + name + "] ");
    }
}

采用配置生成，生成WSDL，发布WSDL服务

package com.example.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.ws.wsdl.wsdl11.DefaultWsdl11Definition;
import org.springframework.xml.xsd.commons.CommonsXsdSchemaCollection;

/**
 * @author 小隐乐乐
 * @since 2021/1/14 23:34
 */
@Configuration
public class EndpointConfig {

    @Bean
    public DefaultWsdl11Definition holiday() {

        DefaultWsdl11Definition definition = new DefaultWsdl11Definition();
        definition.setPortTypeName("HumanResource");
        definition.setLocationUri("/webservices/holidayService/");
        definition.setTargetNamespace("http://mycompany.com/hr/definitions");
        definition.setSchemaCollection(holidayXsd());
        return definition;
    }

    @Bean
    public CommonsXsdSchemaCollection holidayXsd() {

        CommonsXsdSchemaCollection collection = new CommonsXsdSchemaCollection(new ClassPathResource("/hr.xsd"));
        collection.setInline(true);
        return collection;
    }

}

maven插件

用于生成Schema实体

 <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jaxb2-maven-plugin</artifactId>
                <version>2.5.0</version>
                <executions>
                    <execution>
                        <id>xjc</id>
                        <goals>
                            <goal>xjc</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <sources>${project.basedir}/src/main/resources/hr.xsd</sources>
                    <packageName>com.example.demo.schema</packageName>
                    <target>2.1</target>
                </configuration>
            </plugin>

4、应用测试

采用SoapUi完成接口测试。

服务发布地址：http://localhost:8848/webservices/holidayService/holiday.wsdl

服务请求地址：http://localhost:8848/webservices/holidayService

请求报文

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sch="http://mycompany.com/hr/schemas">
   <soapenv:Header/>
   <soapenv:Body>
      <sch:HolidayRequest>
         <!--You may enter the following 2 items in any order-->
         <sch:Holiday>
            <sch:StartDate>2008-09-29</sch:StartDate>
            <sch:EndDate>2014-09-19</sch:EndDate>
         </sch:Holiday>
         <sch:Employee>
            <sch:Number>100</sch:Number>
            <sch:FirstName>verrantque per auras</sch:FirstName>
            <sch:LastName>per auras</sch:LastName>
         </sch:Employee>
      </sch:HolidayRequest>
   </soapenv:Body>
</soapenv:Envelope>

测试完毕，一个简单的应用接口，完成开发。