06-netty之http之檔案伺服器
阿新 • • 發佈:2019-02-01
Netty是一個NIO框架,讓你快速、簡單的的開發網路應用。它是一種新的開發網路應用的方式,使得開發網路應用更加簡單,容易擴充套件。它隱藏了許多複雜的細節,並提供簡單的api讓你的業務邏輯和網路處理程式碼分離開來。Netty的所有api都是非同步的,如果大家不瞭解非同步IO,可以先學習一下非同步IO方面的知識。
package netty.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;
/**
* @author lilinfeng
* @date 2014年2月14日
* @version 1.0
*/
public class HttpFileServer {
// 這裡目錄要寫完整的相對路徑,包括main/java
private static final String DEFAULT_URL = "/src/main/java/netty";
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 {
ch.pipeline().addLast("http-decoder", new HttpRequestDecoder());
ch.pipeline().addLast("http-aggregator", new HttpObjectAggregator(65536));
// 新增HTTP響應編碼器,對HTTP響應訊息進行編碼
ch.pipeline().addLast("http-encoder", new HttpResponseEncoder());
// 新增Chunked handler,主要作用是支援非同步傳送大的碼流(例如大檔案傳輸)
// 但是不佔用過多的記憶體,防止發生java記憶體溢位錯誤
ch.pipeline().addLast("http-chunked", new ChunkedWriteHandler());
// HttpFileServerHandler用於檔案伺服器的業務邏輯處理
ch.pipeline().addLast("fileServerHandler", new HttpFileServerHandler(url));
}
});
String host = "127.0.0.1";
ChannelFuture future = b.bind(host, port).sync();
System.out.println("HTTP檔案目錄伺服器啟動,網址是 : http://" + host +":" + port + url);
future.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
public static void main(String[] args) throws Exception {
int port = 8081;
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);
}
}
package netty.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;
/**
* @author lilinfeng
* @date 2014年2月14日
* @version 1.0
*/
public class HttpFileServerHandler extends
SimpleChannelInboundHandler<FullHttpRequest> {
private final String url;
public HttpFileServerHandler(String url) {
this.url = url;
}
/**
* DefaultFullHttpRequest, decodeResult: success)
* GET /src/main/java/netty/ HTTP/1.1
* Host: 127.0.0.1:8081
* Connection: keep-alive
* Cache-Control: max-age=0
* User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36
* Upgrade-Insecure-Requests: 1
* Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*;q=0.8
* Accept-Encoding: gzip, deflate, br
* Accept-Language: zh-CN,zh;q=0.9
* Content-Length: 0
*
*
* DefaultFullHttpRequest, decodeResult: success)
* GET /favicon.ico HTTP/1.1
* Host: 127.0.0.1:8081
* Connection: keep-alive
* Pragma: no-cache
* Cache-Control: no-cache
* User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.96 Safari/537.36
* Accept: image/webp,image/*,*;q=0.8
* Referer: http://127.0.0.1:8081/src/main/java/netty/
* Accept-Encoding: gzip, deflate, sdch, br
* Accept-Language: zh-CN,zh;q=0.8
* Content-Length: 0
*
* 這裡發現,每次重新整理,或者點選都會有兩個請求,很鬱悶?
* 瀏覽器每次發起請求,都會同時請求一次favicon.ico(本次不討論瀏覽器快取了favicon.ico)
*
*/
@Override
public void messageReceived(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
// 過濾掉瀏覽器每次發起請求,都會同時請求一次favicon.ico
if(request.getUri().equals("/favicon.ico")){
return;
}
System.out.println("伺服器接受訊息"+request);
// 首先對HTTP請求小弟的解碼結果進行判斷,如果解碼失敗,直接構造HTTP 400錯誤返回。
if (!request.getDecoderResult().isSuccess()) {
sendError(ctx, BAD_REQUEST);
return;
}
// 請求方法:如果不是從瀏覽器或者表單設定為get請求,構造http 405錯誤返回
if (request.getMethod() != GET) {
sendError(ctx, METHOD_NOT_ALLOWED);
return;
}
// 對請求的的URL進行包裝
final String uri = request.getUri();
// 展開URL分析
final String path = sanitizeUri(uri);
if (path == null) {
sendError(ctx, FORBIDDEN);
return;
}
File file = new File(path);
// 如果檔案不存在或者是系統隱藏檔案,則構造404 異常返回
if (file.isHidden() || !file.exists()) {
sendError(ctx, NOT_FOUND);
return;
}
// 如果檔案是目錄,則傳送目錄的連線給客戶端瀏覽器
if (file.isDirectory()) {
if (uri.endsWith("/")) {
sendListing(ctx, file);
} else {
sendRedirect(ctx, uri + '/');
}
return;
}
// 使用者在瀏覽器上第幾超連結直接開啟或者下載檔案,合法性監測
if (!file.isFile()) {
sendError(ctx, FORBIDDEN);
return;
}
// IE下才會開啟檔案,其他瀏覽器都是直接下載
// 隨機檔案讀寫類以讀的方式開啟檔案
RandomAccessFile randomAccessFile = null;
try {
randomAccessFile = new RandomAccessFile(file, "r");// 以只讀的方式開啟檔案
} catch (FileNotFoundException fnfe) {
sendError(ctx, NOT_FOUND);
return;
}
// 獲取檔案長度,構建成功的http應答訊息
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;
// 同過netty的村可多File物件直接將檔案寫入到傳送緩衝區,最後為sendFileFeature增加GenericFeatureListener,
// 如果傳送完成,列印“Transfer complete”
sendFileFuture = ctx.write(new ChunkedFile(randomAccessFile, 0,
fileLength, 8192), ctx.newProgressivePromise());
sendFileFuture.addListener(new ChannelProgressiveFutureListener() {
@Override
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);
}
}
@Override
public void operationComplete(ChannelProgressiveFuture future)
throws Exception {
System.out.println("Transfer complete.");
}
});
ChannelFuture lastContentFuture = ctx
.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
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(".*[<>&\"].*");
private String sanitizeUri(String uri) {
try {
// 使用JDK的URLDecoder進行解碼
uri = URLDecoder.decode(uri, "UTF-8");
} catch (UnsupportedEncodingException e) {
try {
uri = URLDecoder.decode(uri, "ISO-8859-1");
} catch (UnsupportedEncodingException e1) {
throw new Error();
}
}
// URL合法性判斷
if (!uri.startsWith(url)) {
return null;
}
if (!uri.startsWith("/")) {
return null;
}
// 將硬編碼的檔案路徑
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\\.]*");
/**
* 這裡是構建了一個html頁面返回給瀏覽器
* @param ctx
* @param dir
*/
private static void sendListing(ChannelHandlerContext ctx, File dir) {
FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, OK);
response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
StringBuilder buf = new StringBuilder();
String dirPath = dir.getPath();
buf.append("<!DOCTYPE html>\r\n");
buf.append("<html><head><title>");
buf.append(dirPath);
buf.append(" 目錄:");
buf.append("</title></head><body>\r\n");
buf.append("<h3>");
buf.append(dirPath).append(" 目錄:");
buf.append("</h3>\r\n");
buf.append("<ul>");
// 此處列印了一個 .. 的連結
buf.append("<li>連結:<a href=\"../\">..</a></li>\r\n");
// 用於展示根目錄下的所有檔案和資料夾,同時使用超連結標識
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>連結:<a href=\"");
buf.append(name);
buf.append("\">");
buf.append(name);
buf.append("</a></li>\r\n");
}
buf.append("</ul></body></html>\r\n");
ByteBuf buffer = Unpooled.copiedBuffer(buf, CharsetUtil.UTF_8);
response.content().writeBytes(buffer);
buffer.release();
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()));
}
}