Jetty 嵌入式开发

Jetty 嵌入式开发

最近，需要从现有的，一个比较庞大的WEB系统中，抽取一部分功能做成一个带操作界面的小工具。由于本人只对WEB比较熟悉，对于AWT、Swing 、SWT 、JFace等等技术不是很了解，最后还是决定使用WEB包装此小工具的操作界面。

为了缩小整个小工具的体积，放弃了TOMCAT选择了JETTY

为了使用户配置起来不是很麻烦，放弃了WAR部署选择了JETTY的嵌入式部署。

之前使用jetty，是将工程打包成war包，再放入jetty的webapps中，使用start.jar启动运行(Eclipse中调试Maven+Jetty 便是使用此方法)

如何使用jetty的嵌入式，网上搜到了很多先辈的博客，都推荐使用 jetty-all (mvnreposity: jetty-all)，但经过多次尝试，均以各种异常失败告终，原因暂时不明。

通过start.jar运行jetty的时候，理论上也就是引用了lib中的jar包

据此思路，基于9.2.12.v20150709版本jetty的lib，添加maven依赖，如下

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<base.jdk.version>1.7</base.jdk.version><!-- jdk版本 -->
<junit.version>4.11</junit.version><!-- junit版本 -->
<!-- spring framework版本 -->
<spring.framework.version>4.2.1.RELEASE</spring.framework.version>
<jackson.version>2.5.0</jackson.version><!-- jackson版本 -->
<eclipse.jetty.version>9.2.12.v20150709</eclipse.jetty.version>
</properties>

<dependencies>

<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
</dependency>

<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-xml</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-webapp</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-util</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlet</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlets</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-server</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-security</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty.toolchain</groupId>
<artifactId>jetty-schemas</artifactId>
<version>3.1.M0</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-rewrite</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-io</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-http</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-deploy</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-continuation</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-client</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<!-- lig/spring -->
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-spring</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<!-- lib/jsp -->
<!-- NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet -->
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>javax.el</artifactId>
<version>3.0.0</version>
</dependency>

<dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>javax.servlet.jsp.jstl</artifactId>
<version>1.2.2</version>
</dependency>

<dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>javax.servlet.jsp</artifactId>
<version>2.3.2</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-jsp</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<!-- lib/apache-jstl -->
<dependency>
<groupId>org.apache.taglibs</groupId>
<artifactId>taglibs-standard-impl</artifactId>
<version>1.2.1</version>
</dependency>

<dependency>
<groupId>org.apache.taglibs</groupId>
<artifactId>taglibs-standard-spec</artifactId>
<version>1.2.1</version>
</dependency>

<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>

<dependency><!-- spring-core -->
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-beans -->
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-context -->
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-context-support -->
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-aop -->
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-expression -->
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-aspects -->
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-web -->
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-mvc -->
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-messaging -->
<groupId>org.springframework</groupId>
<artifactId>spring-messaging</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<!-- JSON -->
<dependency><!-- jackson-core -->
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>

<dependency><!-- jackson-databind -->
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>

<dependency><!-- jackson-annotations -->
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>

<dependency>
<groupId>org.eclipse.jetty.websocket</groupId>
<artifactId>websocket-server</artifactId>
<version>${eclipse.jetty.version}</version>
</dependency>

<dependency><!-- spring-websocket -->
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>${spring.framework.version}</version>
</dependency>

<dependency><!-- spring-messaging -->
<groupId>org.springframework</groupId>
<artifactId>spring-messaging</artifactId>
<version>${spring.framework.version}</version>
</dependency>

</dependencies>

编写主函数

public static void main(String[] args) throws Exception {
File basedir = null;

if (args.length > 0) {
basedir = new File(args[0]);
} else {
basedir = new File(
Thread.currentThread().getContextClassLoader().getResource("").getPath());
}

LOGGER.info("BaseDir: " + basedir.getAbsolutePath());

String descriptor = new File(basedir, "WebContent/WEB-INF/web.xml").getAbsolutePath();
String resourceBase = new File(basedir, "WebContent").getAbsolutePath();

LOGGER.info("Descriptor: " + descriptor);
LOGGER.info("ResourceBase: " + resourceBase);

/* 初始化webserver */
Server server = new Server(8080);

/* 配置webcontent */
WebAppContext context = new WebAppContext();
context.setContextPath("/");
context.setDescriptor(descriptor);
context.setResourceBase(resourceBase);
context.setClassLoader(Thread.currentThread().getContextClassLoader());
context.setConfigurationDiscovered(true);
context.setParentLoaderPriority(true);

server.setHandler(context);

/* 启动web & spring */
server.start();
}

运行没有问题，访问普通页面也没有问题，但在使用jstl的时候，报各种tld找不到

The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application

但在taglibs-standard包的META-INF中，确实存在jstl的tld文件

尝试将tld文件拷贝到web目录下，并配置到web.xml中，如下

<taglib>
<taglib-uri>http://java.sun.com/jsp/jstl/core</taglib-uri>
<taglib-location>/WEB-INF/jstl/c.tld</taglib-location>
</taglib>

但依然报错，考虑到报错的原因，是找不到tld文件，不如直接在jsp中将jstl的uri写成相对路径，如下

<!-- The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application -->
<%@ taglib prefix="c" uri="/jstl/c.tld" %><!-- http://java.sun.com/jsp/jstl/core -->
<%@ taglib prefix="fmt" uri="/jstl/fmt.tld" %><!-- http://java.sun.com/jsp/jstl/functions -->
<%@ taglib prefix="fn" uri="/jstl/fn.tld" %><!-- http://java.sun.com/jsp/jstl/fmt -->

一切正常，至此，jetty嵌入式环境搭建完毕