我构建的 jar 中包含许多静态资源。它是一个码头服务器，静态资源是一个 index.html 和一些其他的 js/css 文件。我需要在运行时编辑 index.html，我想知道如何在启动服务器的 Bootstrap 文件中进行此操作，或者在运行启动脚本时使用 sed 或类似的命令行从命令行进行。
有什么最好的方法来解决这个问题吗？我更喜欢后一种解决方案，我可以通过 shell 命令完成。
谢谢！
【问题讨论】：
这会有问题。
JAR 本身会改变。
运行时不会看到更改（因为 JAR 内容缓存在 Java 中）
需要重新启动二进制文件才能获取更改。
如果您有可以在运行时更改的内容，请将这些内容放在文件系统中的 jar 之外，或者为静态 jar 内容提供文件系统覆盖。
要在 JAR 之外提供内容，请参阅先前的答案...
Serving static files from alternate path in embedded Jetty
要使用替代路径进行覆盖，只需将org.eclipse.jetty.util.resource.ResourceCollection 用于您的context.setBaseResource()
像这样...
package jetty;
import java.io.File;
import java.io.FileNotFoundException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.servlet.DefaultServlet;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jetty.util.resource.PathResource;
import org.eclipse.jetty.util.resource.Resource;
import org.eclipse.jetty.util.resource.ResourceCollection;
public class ResourceCollectionDefaultServlet
{
public static void main(String[] args) throws Exception
{
Server server = new Server();
ServerConnector connector = new ServerConnector(server);
connector.setPort(8080);
server.addConnector(connector);
// Jar Resource
String resourceExample = "/webroot/index.html";
URL jarUrl = server.getClass().getResource(resourceExample);
if(jarUrl == null)
{
throw new FileNotFoundException("Unable to find JAR Resource: " + resourceExample);
}
URI jarUriBase = jarUrl.toURI().resolve("./");
Resource jarResource = Resource.newResource(jarUriBase);
// FileSystem Resource
// Example here uses Path: $TEMP/resource/
// You can pick a location on disk of your own choice (use a System property if you want)
Path fsPath = new File(System.getProperty("java.io.tmpdir")).toPath().resolve("resource");
if(!Files.exists(fsPath))
Files.createDirectory(fsPath);
Resource fsResource = new PathResource(fsPath);
// Resource Collection
ResourceCollection resourceCollection = new ResourceCollection(
fsResource, // check FileSystem first
jarResource // fall back to jar for all content not on filesystem
);
System.out.println("Resource Collection: " + resourceCollection);
ServletContextHandler context = new ServletContextHandler();
context.setContextPath("/");
context.setBaseResource(resourceCollection);
server.setHandler(context);
context.setWelcomeFiles(new String[] { "index.html" });
// TODO: Your servlets and filters here
// Lastly, the default servlet for root content (always needed, to satisfy servlet spec)
// It is important that this is last.
ServletHolder holderPwd = new ServletHolder("default", DefaultServlet.class);
holderPwd.setInitParameter("dirAllowed","true");
context.addServlet(holderPwd,"/");
server.setDumpAfterStart(true);
server.start();
server.join(); // wait on server to stop
}
}
这会设置一个带有 2 个条目的 ResourceCollection。
$TEMP/resource/<requestedResource>
$JARBASEURI/<requestedResource>
上面的输出告诉你它是如何工作的。
服务器转储包含运行 ServletContextHandler 资源库的详细信息。
2018-04-27 10:25:02.314:INFO::main: Logging initialized @338ms to org.eclipse.jetty.util.log.StdErrLog
Resource Collection: [file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/]
2018-04-27 10:25:02.422:INFO:oejs.Server:main: jetty-9.4.9.v20180320; built: 2018-03-20T07:21:10-05:00; git: 1f8159b1e4a42d3f79997021ea1609f2fbac6de5; jvm 9.0.4+11
2018-04-27 10:25:02.477:INFO:oejsh.ContextHandler:main: Started o.e.j.s.ServletContextHandler@13c10b87{/,[file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/],AVAILABLE}
2018-04-27 10:25:02.609:INFO:oejs.AbstractConnector:main: Started ServerConnector@c267ef4{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
org.eclipse.jetty.server.Server@473b46c3[9.4.9.v20180320] - STARTING
...(snip)...
+= o.e.j.s.ServletContextHandler@13c10b87{/,[file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/],AVAILABLE} - STARTED
| += org.eclipse.jetty.servlet.ServletHandler@1aa7ecca - STARTED
| | += default@5c13d641==org.eclipse.jetty.servlet.DefaultServlet,jsp=null,order=-1,inst=false - STARTED
| | | +- dirAllowed=true
| | +- [/]=>default
| +> No ClassLoader
| +> Handler attributes o.e.j.s.ServletContextHandler@13c10b87{/,[file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/],AVAILABLE}
| | +- org.eclipse.jetty.server.Executor=QueuedThreadPool[qtp1018298342]@3cb1ffe6{STARTED,8<=8<=200,i=3,q=0}
| +> Context attributes o.e.j.s.ServletContextHandler@13c10b87{/,[file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/],AVAILABLE}
| | +- org.eclipse.jetty.util.DecoratedObjectFactory=org.eclipse.jetty.util.DecoratedObjectFactory[decorators=1]
| +> Initparams o.e.j.s.ServletContextHandler@13c10b87{/,[file:///C:/Users/joakim/AppData/Local/Temp/resource/, jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/],AVAILABLE}
2018-04-27 10:25:02.651:INFO:oejs.Server:main: Started @682ms
在这次执行中，我可以看到ResourceCollection 有 2 个碱基。
file:///C:/Users/joakim/AppData/Local/Temp/resource/
jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/
因此，如果收到https://myapp.com/js/config.js 的请求，则会发生以下情况...
file:///C:/Users/joakim/AppData/Local/Temp/resource/js/config.js 存在吗？如果有，请上桌。jar:file:///C:/code/jetty-examples/target/project.jar!/webroot/js/config.js 存在吗？如果有，请上桌。【讨论】：