netty
package com.dxz.nettydemo.http;import java.io.UnsupportedEncodingException;import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.http.QueryStringDecoder;class HttpServerHandler extends ChannelInboundHandlerAdapter { @Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws UnsupportedEncodingException { if (msg instanceof HttpRequest) { // 请求，解码器将请求转换成HttpRequest对象
HttpRequest request = (HttpRequest) msg; // 获取请求参数
QueryStringDecoder queryStringDecoder = new QueryStringDecoder(request.getUri());
String name = "World";
if (queryStringDecoder.parameters().get("name") != null) {
name = queryStringDecoder.parameters().get("name").get(0);
} // 响应HTML
String responseHtml = "<html><body>Hello, " + name + "</body></html>";
byte[] responseBytes = responseHtml.getBytes("UTF-8");
int contentLength = responseBytes.length; // 构造FullHttpResponse对象，FullHttpResponse包含message body
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK,
Unpooled.wrappedBuffer(responseBytes));
response.headers().set("Content-Type", "text/html; charset=utf-8");
response.headers().set("Content-Length", Integer.toString(contentLength)); ctx.writeAndFlush(response);
}
} @Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
主类：
package com.dxz.nettydemo.http;import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpServerCodec;public class HttpServer { public static void main(String[] args) throws InterruptedException {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new HttpServerCodec());
pipeline.addLast(new HttpServerHandler());
}
});
ChannelFuture f = b.bind(8080).sync();
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}
}
测试：
用浏览器访问：http://localhost:8080/
netty构建的文件服务器
1、首先加入的是HTTP请求消息解码器
ch.pipeline().addLast(“http-decoder”, new HttpRequestDecoder());
2、第2添加HttpObjectAggregator解密器，其作用是将多个消息转换为单一的FullHttpRequest或者FullHttpResponse，原因是HTTP解码器在每个HTTP消息中会生成多个消息对象：有1、HttpRequest/HttpResponse;2、HttpContent；3、LastHttpContent；
ch.pipeline().addLast(“http-aggregator”, new HttpObjectAggregator(65536));
3、第3增加HTTP响应编码器，对HTTP响应信息进行编码
ch.pipeline().addLast(“http-encoder”, new HttpResponseEncoder());
4、第4Chunked handler的主要作用是支持异步发送大的码流（例如大的文件传输），但不占用过多的内存，防止发生JAVA内存溢出错误
ch.pipeline().addLast(“http-chunked”, new ChunkedWriteHandler());
5、第5HttpFileServerHandler用于文件服务器的业务逻辑处理
package com.dxz.nettydemo.http;import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.stream.ChunkedWriteHandler;public class HttpFileServer { private static final String DEFAULT_URL = "/src/main/java/com/dxz/nettydemo/http"; public void run(final int port, final String url) throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
//首先加入的是HTTP请求消息解码器
ch.pipeline().addLast("http-decoder", new HttpRequestDecoder());
//第2添加HttpObjectAggregator解密器，其作用是将多个消息转换为单一的FullHttpRequest或者FullHttpResponse，
//原因是HTTP解码器在每个HTTP消息中会生成多个消息对象：有1、HttpRequest/HttpResponse;2、HttpContent；3、LastHttpContent；
ch.pipeline().addLast("http-aggregator", new HttpObjectAggregator(65536));
//第3增加HTTP响应编码器，对HTTP响应信息进行编码
ch.pipeline().addLast("http-encoder", new HttpResponseEncoder());
//第4Chunked handler的主要作用是支持异步发送大的码流（例如大的文件传输），但不占用过多的内存，防止发生JAVA内存溢出错误
ch.pipeline().addLast("http-chunked", new ChunkedWriteHandler());
//第5HttpFileServerHandler用于文件服务器的业务逻辑处理
ch.pipeline().addLast("fileServerHandler", new HttpFileServerHandler(url));
}
});
ChannelFuture future = b.bind("localhost", port).sync();
System.out.println("HTTP文件目录服务器启动，网址是 : " + "http://localhost:" + port + url);
future.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
} public static void main(String[] args) throws Exception {
int port = 8080;
if (args.length > 0) {
try {
port = Integer.parseInt(args[0]);
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
String url = DEFAULT_URL;
if (args.length > 1)
url = args[1];
new HttpFileServer().run(port, url);
}
}
文件读取下载
package com.dxz.nettydemo.http;import static io.netty.handler.codec.http.HttpHeaders.isKeepAlive;
import static io.netty.handler.codec.http.HttpHeaders.setContentLength;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Names.LOCATION;
import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
import static io.netty.handler.codec.http.HttpResponseStatus.FOUND;
import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
import static io.netty.handler.codec.http.HttpResponseStatus.METHOD_NOT_ALLOWED;
import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelProgressiveFuture;
import io.netty.channel.ChannelProgressiveFutureListener;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.LastHttpContent;
import io.netty.handler.stream.ChunkedFile;
import io.netty.util.CharsetUtil;import java.io.File;
import java.io.FileNotFoundException;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.regex.Pattern;import javax.activation.MimetypesFileTypeMap;public class HttpFileServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
private final String url; public HttpFileServerHandler(String url) {
this.url = url;
} @Override
public void messageReceived(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
//http请求消息解码结果的判断，如果解码失败，直接返回构造HTTP400 错误返回
if (!request.getDecoderResult().isSuccess()) {
sendError(ctx, BAD_REQUEST);
return;
}
if (request.getMethod() != GET) {
sendError(ctx, METHOD_NOT_ALLOWED);
return;
}
final String uri = request.getUri();
final String path = sanitizeUri(uri);
if (path == null) {
sendError(ctx, FORBIDDEN);
return;
}
File file = new File(path);
if (file.isHidden() || !file.exists()) {
sendError(ctx, NOT_FOUND);
return;
}
if (file.isDirectory()) {
if (uri.endsWith("/")) {
sendListing(ctx, file);
} else {
sendRedirect(ctx, uri + '/');
}
return;
}
if (!file.isFile()) {
sendError(ctx, FORBIDDEN);
return;
}
RandomAccessFile randomAccessFile = null;
try {
randomAccessFile = new RandomAccessFile(file, "r");// 以只读的方式打开文件
} catch (FileNotFoundException fnfe) {
sendError(ctx, NOT_FOUND);
return;
} //待下载文件的长度
long fileLength = randomAccessFile.length();
HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
setContentLength(response, fileLength);
setContentTypeHeader(response, file);
if (isKeepAlive(request)) {
response.headers().set(CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
}
ctx.write(response);
ChannelFuture sendFileFuture;
//通过netty的ChunkedFile对象将文件写入到发送缓冲区
sendFileFuture = ctx.write(new ChunkedFile(randomAccessFile, 0, fileLength, 8192), ctx.newProgressivePromise());
sendFileFuture.addListener(new ChannelProgressiveFutureListener() {
public void operationProgressed(ChannelProgressiveFuture future, long progress, long total) {
if (total < 0) { // total unknown
System.err.println("Transfer progress: " + progress);
} else {
System.err.println("Transfer progress: " + progress + " / " + total);
}
} public void operationComplete(ChannelProgressiveFuture future) throws Exception {
System.out.println("Transfer complete.");
}
});
//使用chunked编码，最后需要发送一个编码结束 的空消息体，将LastHttpContent的EMPTY_LAST_CONTENT发送到缓冲区中，标识所有的消息体已经发送完成，同时
//用flush方法将之前在发送缓冲区的消息刷新到SocketChannel中发送给对方
ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
//如果不是keep-alive，服务端在发送完成之后，服务端主动关闭连接
if (!isKeepAlive(request)) {
lastContentFuture.addListener(ChannelFutureListener.CLOSE);
}
} @Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
if (ctx.channel().isActive()) {
sendError(ctx, INTERNAL_SERVER_ERROR);
}
} private static final Pattern INSECURE_URI = Pattern.compile(".*[<>&\"].*"); /**
* 请求路径的处理
* @param uri
* @return
*/
private String sanitizeUri(String uri) {
try {
uri = URLDecoder.decode(uri, "UTF-8");
} catch (UnsupportedEncodingException e) {
try {
uri = URLDecoder.decode(uri, "ISO-8859-1");
} catch (UnsupportedEncodingException e1) {
throw new Error();
}
}
if (!uri.startsWith(url)) {
return null;
}
if (!uri.startsWith("/")) {
return null;
}
uri = uri.replace('/', File.separatorChar);
if (uri.contains(File.separator + '.') || uri.contains('.' + File.separator) || uri.startsWith(".")
|| uri.endsWith(".") || INSECURE_URI.matcher(uri).matches()) {
return null;
}
return System.getProperty("user.dir") + File.separator + uri;
} private static final Pattern ALLOWED_FILE_NAME = Pattern.compile("[A-Za-z0-9][-_A-Za-z0-9\\.]*"); private static void sendListing(ChannelHandlerContext ctx, File dir) {
//创建成功的HTTP响应消息
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK);
//设置消息头类型
response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
//构造响应消息体
StringBuilder buf = new StringBuilder();
String dirPath = dir.getPath();
buf.append("<!DOCTYPE html>\r\n");
buf.append("<html><head><title>");
buf.append(dirPath);
buf.append(" 目录：");
buf.append("</title></head><body>\r\n");
buf.append("<h3>");
buf.append(dirPath).append(" 目录：");
buf.append("</h3>\r\n");
buf.append("<ul>");
buf.append("<li>链接：<a href=\"../\">..</a></li>\r\n");
for (File f : dir.listFiles()) {
if (f.isHidden() || !f.canRead()) {
continue;
}
String name = f.getName();
if (!ALLOWED_FILE_NAME.matcher(name).matches()) {
continue;
}
buf.append("<li>链接：<a href=\"");
buf.append(name);
buf.append("\">");
buf.append(name);
buf.append("</a></li>\r\n");
}
buf.append("</ul></body></html>\r\n");
//分配对应消息的缓冲对象
ByteBuf buffer = Unpooled.copiedBuffer(buf, CharsetUtil.UTF_8);
//将缓冲区中的响应消息存放到HTTP应答消息中
response.content().writeBytes(buffer);
//释放缓冲区
buffer.release();
//将响应消息刷新到SocketChannel中
ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
} private static void sendRedirect(ChannelHandlerContext ctx, String newUri) {
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, FOUND);
response.headers().set(LOCATION, newUri);
ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
} private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, status,
Unpooled.copiedBuffer("Failure: " + status.toString() + "\r\n", CharsetUtil.UTF_8));
response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");
ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
} private static void setContentTypeHeader(HttpResponse response, File file) {
MimetypesFileTypeMap mimeTypesMap = new MimetypesFileTypeMap();
response.headers().set(CONTENT_TYPE, mimeTypesMap.getContentType(file.getPath()));
}
}
演示：
