使用JSP使用嵌入式Jetty会出现错误“web-jsptaglibrary_1_2.dtd not found”

我使用嵌入式Jetty来启动webapp,我使用JSP页面作为视图.

使用maven-jetty-plugin可以很好地进行测试,这让我觉得我在引导服务器时缺少一些依赖项(这是问题的根本原因).

我用命令引导Jetty：

java $JAVA_OPTS -cp target/classes:target/dependency/* xxx.Main

我已经在Maven中使用了依赖插件,以确保获得类路径上的所有deps(在打包的war文件之外)：

<execution>
<id>copy-dep</id>
<goals>
<goal>copy-dependencies</goal>
</goals>
</execution>

Main类看起来像这样：

Server server = new Server(8080);
    WebAppContext root = new WebAppContext();
    root.setContextPath("/");
    root.setWar("target/app.war");
    server.setHandler(root);
    server.start();
    server.join();

嵌入式Jetty服务器启动时没有错误,但是当导航到返回JSP页面的URL时,我总是会收到此错误.

堆栈跟踪：

PWC6181: File /javax/servlet/jsp/resources/web-jsptaglibrary_1_2.dtd not found

Caused by:

org.xml.sax.SAXException: PWC6181: File /javax/servlet/jsp/resources/web-jsptaglibrary_1_2.dtd not found
at org.apache.jasper.xmlparser.MyEntityResolver.resolveEntity(ParserUtils.java:566)
at com.sun.org.apache.xerces.internal.util.EntityResolverWrapper.resolveEntity(EntityResolverWrapper.java:107)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.resolveEntityAsPerStax(XMLEntityManager.java:1018)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1192)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1090)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1003)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119)
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:235)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:284)
at org.apache.jasper.xmlparser.ParserUtils.parseXMLDocument(ParserUtils.java:296)
at org.apache.jasper.xmlparser.ParserUtils.parseXMLDocument(ParserUtils.java:366)
at org.apache.jasper.runtime.TldScanner.scanTld(TldScanner.java:526)
at org.apache.jasper.runtime.TldScanner.scanJar(TldScanner.java:379)
at org.apache.jasper.runtime.TldScanner.scanJars(TldScanner.java:607)
at org.apache.jasper.runtime.TldScanner.scanTlds(TldScanner.java:282)
at org.apache.jasper.runtime.TldScanner.getLocation(TldScanner.java:255)

我使用Jetty 8,我的web.xml配置为Servlet 3.0.

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

我发现缺少dtd文件的问题是我需要Jetty JSP JAR.

当它不起作用时,我正在使用这些依赖项来支持JSP：

<dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.web</groupId>
        <artifactId>jsp-impl</artifactId>
        <version>2.2</version>
    </dependency>

Jetty-runner总是为我工作所以我查看了jar文件中的依赖项.

<dependency>
    <groupId>org.eclipse.jetty.orbit</groupId>
    <artifactId>javax.servlet.jsp</artifactId>
    <version>2.2.0.v201112011158</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty.orbit</groupId>
    <artifactId>org.apache.jasper.glassfish</artifactId>
    <version>2.2.2.v201112011158</version>
</dependency>

在javax.servlet.jsp依赖项中存在缺少的dtd文件,因此当我开始使用它们时问题就消失了.

所以我想问题是我需要Jetty特定的JSP依赖,而不是一般的.谁能解释为什么Jetty以这种方式实现？