带有Servlet 3.0的嵌入式Tomcat-如何在扫描时跳过某些jar？

小编典典

带有Servlet 3.0的嵌入式Tomcat-如何在扫描时跳过某些jar？

tomcat

这是嵌入式Tomcat服务器扫描Servlet 3.0初始化程序的简单方法：

public static void main(String[] args) throws ServletException, LifecycleException {
    Tomcat tomcat = new Tomcat();
    tomcat.setPort(8080);

    StandardContext ctx = (StandardContext) tomcat.addWebapp("/", new File("web").getAbsolutePath());

    //declare an alternate location for your "WEB-INF/classes" dir:     
    File additionWebInfClasses = new File("target/classes");
    VirtualDirContext resources = new VirtualDirContext();
    resources.setExtraResourcePaths("/WEB-INF/classes=" + additionWebInfClasses);
    ctx.setResources(resources);

    tomcat.start();
    System.out.println("Started");
    tomcat.getServer().await();
}

我知道属性tomcat.util.scan.DefaultJarScanner.jarsToSkip中catalina.properties允许你这瓶被扫描加快部署时间限制。我如何将相同的想法整合到嵌入式Tomcat代码中？

奖励：有没有一种方法可以指定要包括的jar而不是要 跳过的 jar ？

阅读 637

2020-06-16

共1个答案

小编典典

尽管我没有特定的方式来加载单个catalina.properties属性，但我发现它很方便，只需将JarScanner本身重载在Tomcat容器上下文中，如下所示：

答案在Groovy中 （对不起，我很懒）

public static void main(String[] args) throws ServletException, LifecycleException {
    Tomcat tomcat = new TomcatWithFastJarScanner()
    tomcat.setPort(8080)

    StandardContext ctx = (StandardContext) tomcat.addWebapp("/", new File("web").getAbsolutePath())

    //declare an alternate location for your "WEB-INF/classes" dir:     
    VirtualDirContext resources = new VirtualDirContext()
    resources.setExtraResourcePaths("/WEB-INF/classes=" + new File("target/classes"))
    ctx.setResources(resources)

    tomcat.start()
    println "Started server on port 8080"
    tomcat.getServer().await()
}

private static class TomcatWithFastJarScanner extends Tomcat {
    @Override
    public void start() throws LifecycleException {
        getServer().findServices().each { service ->
            service.getContainer().findChildren().each { container ->
                container.findChildren().each { c ->
                    ((Context) c).setJarScanner(new FastJarScanner())
                }
            }
        }
        super.start()
    }
}


private static class FastJarScanner extends StandardJarScanner {
    def jarsToInclude = [ 'spring-web.*' ]

    @Override
    public void scan(ServletContext context, ClassLoader classloader,
            JarScannerCallback callback, Set<String> jarsToSkip) {
        jarsToSkip = new HashSet<String>();

        ((URLClassLoader) classloader.getParent()).getURLs().each {
            def jar = it.path.find(/[^\/]+\.jar$/)
            if(!jar) return
            for(String inclusionPattern : jarsToInclude) {
                if(jar.find(inclusionPattern))  
                    println "including jar: " + jar
                else jarsToSkip.add(jar)
            }
        }

        super.scan(context, classloader, callback, jarsToSkip);
    }
}

基本思想是，我们正在查看类加载器可以看到的所有jar，并排除了我们不想包含的所有jar。

Tomcat嵌入式可以像这样快速启动！

2020-06-16