Axis1.4底层加载server-config.wsdd文件的过程

Posted 2020-07-26 Into子房

曾经做过两年的Axis2开发Webservice的各种接口，传参是XML报文，到如今已经快两年没怎么接触过Webservice相关的内容了。前一周，接了个需求，需要对外部系统提供一个Webservice接口，于是又回来折腾Webservice相关的东东。

因为看到外部系统之前与我们公司核心系统对接的Webservice采用的都是axis1.4的，于是，我就用axis1.4下弄了个小demo，因为考虑到业务需求，将最简单的demo升级了一下，传参入参自己设计了一套javaBean，就是之前的一篇文章里的demo。之后再结合业务需求，将这个demo放入到现有的系统中，各种测试都没有问题。

然而，虽然通过demo和网上的资料知道了Webservice的搭建过程，却不知道Webservice底层是怎么操作的，server-config.wsdd文件又是怎么加载的，于是，又把axis1.4相关的jar包都大致浏览了一遍。

首先，配置web.xml的时候，有这样的一段代码：

<listener>
		<listener-class>org.apache.axis.transport.http.AxisHTTPSessionListener</listener-class>
	</listener>
	
	<servlet>
		<servlet-name>AxisServlet</servlet-name>
		<servlet-class>
			org.apache.axis.transport.http.AxisServlet
		</servlet-class> 		
		<load-on-startup>2</load-on-startup>
	</servlet>
	
	<servlet-mapping>
		<servlet-name>AxisServlet</servlet-name>
		<url-pattern>/servlet/AxisServlet</url-pattern>
	</servlet-mapping>

	<servlet-mapping>
		<servlet-name>AxisServlet</servlet-name>
		<url-pattern>/services/*</url-pattern>
	</servlet-mapping>

　　可以看到，axis其实本质还是一个servlet，通过路径org.apache.axis.transport.http.AxisServlet，找到这个servlet的初始化方法：

public class AxisServlet extends AxisServletBase：

 public void init()
    throws ServletException
  {
    super.init();
    ServletContext context = getServletConfig().getServletContext();

    isDebug = log.isDebugEnabled();
    if (isDebug) {
      log.debug("In servlet init");
    }
    this.transportName = getOption(context, "transport.name", "http");

    if (JavaUtils.isTrueExplicitly(getOption(context, "use-servlet-security", null)))
    {
      this.securityProvider = new ServletSecurityProvider();
    }

    this.enableList = JavaUtils.isTrueExplicitly(getOption(context, "axis.enableListQuery", null));

    this.jwsClassDir = getOption(context, "axis.jws.servletClassDir", null);

    this.disableServicesList = JavaUtils.isTrue(getOption(context, "axis.disableServiceList", "false"));

    this.servicesPath = getOption(context, "axis.servicesPath", "/services/");

    if (this.jwsClassDir != null) {
      if (getHomeDir() != null)
        this.jwsClassDir = (getHomeDir() + this.jwsClassDir);
    }
    else {
      this.jwsClassDir = getDefaultJWSClassDir();
    }

    initQueryStringHandlers();
    try
    {
      ServiceAdmin.setEngine(getEngine(), context.getServerInfo());
    } catch (AxisFault af) {
      exceptionLog.info("Exception setting AxisEngine on ServiceAdmin " + af);
    }
  }

　　一般初始化的时候都会去加载各种需要的配置文件，这个servlet继承的父类里有这样的方法：（由上到下，分别是方法调用的过程）

AxisServletBase：

public void init()
    throws ServletException
  {
    ServletContext context = getServletConfig().getServletContext();

    this.webInfPath = context.getRealPath("/WEB-INF");
    this.homeDir = context.getRealPath("/");

    isDebug = log.isDebugEnabled();
    if (log.isDebugEnabled()) log.debug("In AxisServletBase init");
    this.isDevelopment = JavaUtils.isTrueExplicitly(getOption(context, "axis.development.system", null));
  }
  
 protected String getOption(ServletContext context, String param, String dephault)
  {
    String value = AxisProperties.getProperty(param);

    if (value == null) {
      value = getInitParameter(param);
    }
    if (value == null)
      value = context.getInitParameter(param);
    try {
      AxisServer engine = getEngine(this);
      if ((value == null) && (engine != null))
        value = (String)engine.getOption(param);
    }
    catch (AxisFault axisFault) {
    }
    return (value != null) ? value : dephault;
  }
  
   
  public static AxisServer getEngine(HttpServlet servlet)
    throws AxisFault
  {
    AxisServer engine = null;
    if (isDebug) {
      log.debug("Enter: getEngine()");
    }
    ServletContext context = servlet.getServletContext();
    synchronized (context) {
      engine = retrieveEngine(servlet);
      if (engine == null) {
        Map environment = getEngineEnvironment(servlet);

        engine = AxisServer.getServer(environment);

        engine.setName(servlet.getServletName());
        storeEngine(servlet, engine);
      }
    }

    if (isDebug) {
      log.debug("Exit: getEngine()");
    }
    return engine;
  }
  
  
  protected static Map getEngineEnvironment(HttpServlet servlet)
  {
    Map environment = new HashMap();

    String attdir = servlet.getInitParameter("axis.attachments.Directory");
    if (attdir != null) {
      environment.put("axis.attachments.Directory", attdir);
    }
    ServletContext context = servlet.getServletContext();
    environment.put("servletContext", context);

    String webInfPath = context.getRealPath("/WEB-INF");
    if (webInfPath != null) {
      environment.put("servlet.realpath", webInfPath + File.separator + "attachments");
    }

    EngineConfiguration config = EngineConfigurationFactoryFinder.newFactory(servlet).getServerEngineConfig();

    if (config != null) {
      environment.put("engineConfig", config);
    }

    return environment;
  }

　　于是，我发现了EngineConfigurationFactoryFinder.newFactory(servlet).getServerEngineConfig();这个方法在axis的jar包中的这个类里：EngineConfigurationFactoryServlet

private static EngineConfiguration getServerEngineConfig(ServletConfig cfg)
  {
    ServletContext ctx = cfg.getServletContext();

    String configFile = cfg.getInitParameter("axis.ServerConfigFile");
    if (configFile == null) {
      configFile = AxisProperties.getProperty("axis.ServerConfigFile");
    }
    if (configFile == null) {
      configFile = "server-config.wsdd";
    }

    String appWebInfPath = "/WEB-INF";

    FileProvider config = null;

    String realWebInfPath = ctx.getRealPath(appWebInfPath);

    if ((realWebInfPath == null) || (!new File(realWebInfPath, configFile).exists()))
    {
      String name = appWebInfPath + "/" + configFile;
      InputStream is = ctx.getResourceAsStream(name);
      if (is != null)
      {
        config = new FileProvider(is);
      }

      if (config == null) {
        log.error(Messages.getMessage("servletEngineWebInfError03", name));
      }

    }

    if ((config == null) && (realWebInfPath != null)) {
      try {
        config = new FileProvider(realWebInfPath, configFile);
      } catch (ConfigurationException e) {
        log.error(Messages.getMessage("servletEngineWebInfError00"), e);
      }

    }

    if (config == null) {
      log.warn(Messages.getMessage("servletEngineWebInfWarn00"));
      try {
        InputStream is = ClassUtils.getResourceAsStream(AxisServer.class, "server-config.wsdd");

        config = new FileProvider(is);
      } catch (Exception e) {
        log.error(Messages.getMessage("servletEngineWebInfError02"), e);
      }
    }

    return config;
  }
}

　　找到这里，我们就可以知道，axis 的servlet是怎么取找server-config.wsdd文件，进而知道我们配置了那些service了。