Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.tajo.ws.rs.netty; import io.netty.buffer.*; import io.netty.channel.*; import io.netty.channel.ChannelHandler.Sharable; import io.netty.handler.codec.http.*; import io.netty.handler.ssl.SslHandler; import io.netty.util.CharsetUtil; import io.netty.util.ReferenceCountUtil; import io.netty.util.concurrent.GenericFutureListener; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.glassfish.hk2.api.ServiceLocator; import org.glassfish.jersey.internal.MapPropertiesDelegate; import org.glassfish.jersey.server.*; import org.glassfish.jersey.server.internal.ConfigHelper; import org.glassfish.jersey.server.spi.Container; import org.glassfish.jersey.server.spi.ContainerLifecycleListener; import org.glassfish.jersey.server.spi.ContainerResponseWriter; import javax.ws.rs.core.Application; import javax.ws.rs.core.MultivaluedMap; import javax.ws.rs.core.SecurityContext; import java.io.OutputStream; import java.net.InetSocketAddress; import java.net.URI; import java.net.URISyntaxException; import java.security.Principal; import java.util.List; import java.util.Map.Entry; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicBoolean; /** * Jersy Container implementation on Netty */ @Sharable public class NettyRestHandlerContainer extends ChannelDuplexHandler implements Container { private static Log LOG = LogFactory.getLog(NettyRestHandlerContainer.class); private String rootPath; private ApplicationHandler applicationHandler; private ContainerLifecycleListener lifecycleListener; NettyRestHandlerContainer(Application application) { this(new ApplicationHandler(application)); } NettyRestHandlerContainer(Application application, ServiceLocator parentLocator) { this(new ApplicationHandler(application, null, parentLocator)); } NettyRestHandlerContainer(ApplicationHandler appHandler) { applicationHandler = appHandler; lifecycleListener = ConfigHelper.getContainerLifecycleListener(applicationHandler); } public ApplicationHandler getApplicationHandler() { return applicationHandler; } @Override public ResourceConfig getConfiguration() { return applicationHandler.getConfiguration(); } @Override public void reload() { reload(getConfiguration()); } @Override public void reload(ResourceConfig configuration) { lifecycleListener.onShutdown(this); applicationHandler = new ApplicationHandler(configuration); lifecycleListener = ConfigHelper.getContainerLifecycleListener(applicationHandler); lifecycleListener.onReload(this); lifecycleListener.onStartup(this); if (LOG.isDebugEnabled()) { LOG.debug("NettyRestHandlerContainer reloaded."); } } public void setRootPath(String rootPath) { String tempRootPath = rootPath; if (tempRootPath == null || tempRootPath.isEmpty()) { tempRootPath = "/"; } else if (tempRootPath.charAt(tempRootPath.length() - 1) != '/') { tempRootPath += "/"; } this.rootPath = tempRootPath; } private URI getBaseUri(ChannelHandlerContext ctx, FullHttpRequest request) { URI baseUri; String scheme; if (ctx.pipeline().get(SslHandler.class) == null) { scheme = "http"; } else { scheme = "https"; } List<String> hosts = request.headers().getAll(HttpHeaders.Names.HOST); try { if (hosts != null && hosts.size() > 0) { baseUri = new URI(scheme + "://" + hosts.get(0) + rootPath); } else { InetSocketAddress localAddress = (InetSocketAddress) ctx.channel().localAddress(); baseUri = new URI(scheme, null, localAddress.getHostName(), localAddress.getPort(), rootPath, null, null); } } catch (URISyntaxException e) { throw new IllegalArgumentException(e); } return baseUri; } protected void messageReceived(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception { URI baseUri = getBaseUri(ctx, request); URI requestUri = baseUri.resolve(request.getUri()); ByteBuf responseContent = PooledByteBufAllocator.DEFAULT.buffer(); FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, responseContent); NettyRestResponseWriter responseWriter = new NettyRestResponseWriter(ctx, response); ContainerRequest containerRequest = new ContainerRequest(baseUri, requestUri, request.getMethod().name(), getSecurityContext(), new MapPropertiesDelegate()); containerRequest.setEntityStream(new ByteBufInputStream(request.content())); HttpHeaders httpHeaders = request.headers(); for (String headerName : httpHeaders.names()) { List<String> headerValues = httpHeaders.getAll(headerName); containerRequest.headers(headerName, headerValues); } containerRequest.setWriter(responseWriter); try { applicationHandler.handle(containerRequest); } finally { responseWriter.releaseConnection(); } } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { boolean needRelease = true; try { if (msg instanceof FullHttpRequest) { FullHttpRequest request = (FullHttpRequest) msg; messageReceived(ctx, request); } else { needRelease = false; ctx.fireChannelRead(msg); } } finally { if (needRelease) { ReferenceCountUtil.release(msg); } } } private SecurityContext getSecurityContext() { return new SecurityContext() { @Override public boolean isUserInRole(String role) { return false; } @Override public boolean isSecure() { return false; } @Override public Principal getUserPrincipal() { return null; } @Override public String getAuthenticationScheme() { return null; } }; } /** * Internal class for writing content on REST service. */ static class NettyRestResponseWriter implements ContainerResponseWriter { private final ChannelHandlerContext ctx; private final FullHttpResponse response; private final AtomicBoolean closed; public NettyRestResponseWriter(ChannelHandlerContext ctx, FullHttpResponse response) { this.ctx = ctx; this.response = response; this.closed = new AtomicBoolean(false); } @Override public void commit() { if (closed.compareAndSet(false, true)) { ctx.write(response); sendLastHttpContent(); } } @Override public boolean enableResponseBuffering() { return false; } @Override public void failure(Throwable error) { try { sendError(HttpResponseStatus.INTERNAL_SERVER_ERROR, error); } finally { if (ctx.channel().isActive()) { ctx.close(); } } } private void sendError(HttpResponseStatus status, final Throwable error) { FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, status, Unpooled.copiedBuffer(error.getMessage(), CharsetUtil.UTF_8)); response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/plain; charset=UTF-8"); ChannelPromise promise = ctx.newPromise(); promise.addListener(new GenericFutureListener<ChannelFuture>() { @Override public void operationComplete(ChannelFuture future) throws Exception { if (!future.isSuccess()) { throw new ContainerException(error); } } }); ctx.writeAndFlush(response, promise); } @Override public void setSuspendTimeout(long timeOut, TimeUnit timeUnit) throws IllegalStateException { throw new UnsupportedOperationException("setSuspendTimeout is not supported on this container."); } @Override public boolean suspend(long timeOut, TimeUnit timeUnit, TimeoutHandler timeoutHandler) { throw new UnsupportedOperationException("suspend is not supported on this container."); } @Override public OutputStream writeResponseStatusAndHeaders(long contentLength, ContainerResponse context) throws ContainerException { MultivaluedMap<String, String> responseHeaders = context.getStringHeaders(); HttpHeaders nettyHeaders = response.headers(); for (Entry<String, List<String>> entry : responseHeaders.entrySet()) { nettyHeaders.add(entry.getKey(), entry.getValue()); } int status = context.getStatus(); response.setStatus(HttpResponseStatus.valueOf(status)); return new ByteBufOutputStream(response.content()); } private void sendLastHttpContent() { ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT).addListener(ChannelFutureListener.CLOSE); } private void releaseConnection() { if (closed.compareAndSet(false, true)) { String warnMessage = "ResponseWriter did not be commited."; LOG.warn(warnMessage); failure(new IllegalStateException(warnMessage)); } } } }