我使用http / 2编译我的jetty项目当我尝试访问它时，它会返回：
java.io.IOException: java.lang.NullPointerException
at org.eclipse.jetty.server.HttpOutput.write(HttpOutput.java:229)
at org.eclipse.jetty.server.HttpOutput.write(HttpOutput.java:496)
at org.springframework.util.StreamUtils.copy(StreamUtils.java:128)
at org.springframework.http.converter.ResourceHttpMessageConverter.writeContent(ResourceHttpMessageConverter.java:115)
at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:107)
at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:50)
at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:227)
at org.springframework.web.servlet.resource.ResourceHttpRequestHandler.handleRequest(ResourceHttpRequestHandler.java:380)
at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:51)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:845)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1689)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1676)
at com.mamuso.rest.base.security.filters.SimpleCorsFilter.doFilter(SimpleCorsFilter.java:37)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1676)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:581)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1180)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:511)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1112)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
at org.eclipse.jetty.server.Server.handle(Server.java:523)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:320)
at org.eclipse.jetty.server.HttpChannel.run(HttpChannel.java:267)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:671)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:589)
at java.lang.Thread.run(Thread.java:745)
但是，如果我使用htttp1生成图像，它可以正常工作
这是我实例化服务器的地方：
QueuedThreadPool threadPool = new QueuedThreadPool();
threadPool.setMaxThreads(500);
mServer = new Server(threadPool);
mServer.addBean(new ScheduledExecutorScheduler());
HttpConfiguration httpConfig = new HttpConfiguration();
httpConfig.setSecureScheme("https");
httpConfig.setSecurePort(mAppConfig.getServerPort());
HandlerCollection handlers = new HandlerCollection();
ContextHandlerCollection contexts = new ContextHandlerCollection();
handlers.setHandlers(new Handler[] {contexts, new DefaultHandler()});
mServer.setHandler(handlers);
mServer.setDumpAfterStart(false);
mServer.setDumpBeforeStop(false);
mServer.setStopAtShutdown(true);
这里我定义的是类型http2：
SslContextFactory sslContextFactory = new SslContextFactory();
sslContextFactory.setKeyStorePath(mAppConfig.getServerKeystorePath());
sslContextFactory.setKeyStorePassword(mAppConfig.getServerKeystorePassword());
sslContextFactory.setCipherComparator(HTTP2Cipher.COMPARATOR);
sslContextFactory.setUseCipherSuitesOrder(true);
// IMPROVE: exclude all but used ones? do not hardcode?
sslContextFactory.setExcludeCipherSuites("SSL_RSA_WITH_DES_CBC_SHA",
"SSL_DHE_RSA_WITH_DES_CBC_SHA",
"SSL_DHE_DSS_WITH_DES_CBC_SHA",
"SSL_RSA_EXPORT_WITH_RC4_40_MD5",
"SSL_RSA_EXPORT_WITH_DES40_CBC_SHA",
"SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA",
"SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA");
// SSL HTTP Configuration
HttpConfiguration httpsConfig = new HttpConfiguration(httpConfig);
httpsConfig.addCustomizer(new SecureRequestCustomizer());
// HTTP/2 Connection Factory
HTTP2ServerConnectionFactory h2 = new HTTP2ServerConnectionFactory(httpsConfig);
NegotiatingServerConnectionFactory.checkProtocolNegotiationAvailable();
ALPNServerConnectionFactory alpn = new ALPNServerConnectionFactory();
alpn.setDefaultProtocol("h2");
// SSL Connection Factory
SslConnectionFactory ssl = new SslConnectionFactory(sslContextFactory,
alpn.getProtocol());
// HTTP/2 Connector
ServerConnector http2Connector =
new ServerConnector(mServer,ssl, alpn, h2,
new HttpConnectionFactory(httpsConfig));
http2Connector.setPort(mAppConfig.getServerPort());
http2Connector.setIdleTimeout(IDLE_TIMEOUT);
mServer.addConnector(http2Connector);