浏览器请求,根据地址,列出本地目录,点击具体文件可以查看右键另存为下载。,示例可以直接运行,只需要添加对应的 netty 包就可以,
注意: DEFAULT_URL
这个值是需要根据自己电脑目录进行修改的。
HttpFileServer.java
package club.wujingjian.com.wujingjian.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;
public class HttpFileServer {
private static final String DEFAULT_URL = "/accumulate-common/src/main/";
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 socketChannel) throws Exception {
socketChannel.pipeline().addLast("http-decoder", new HttpRequestDecoder());
//HttpObjectAggregator 作用是将多个消息转换为单一的FullHttpRequest或者FullHttpResponse,原因是Http解码器会在每个HTTP消息中会生成多个消息对象
//1. HttpRequest / HttpResponse
//2. HttpContent
//3. LastHttpContent
socketChannel.pipeline().addLast("http-aggregator", new HttpObjectAggregator(65536));
//对HTTP响应消息进行编码
socketChannel.pipeline().addLast("http-encoder", new HttpResponseEncoder());
//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
socketChannel.pipeline().addLast("http-chunked", new ChunkedWriteHandler());
socketChannel.pipeline().addLast("fileServerHandler", new HttpFileServerHandler(url));
}
});
ChannelFuture f = b.bind("127.0.0.1", port).sync();
System.out.println("HTTP 文件目录服务器启动,网址是: " + "http://127.0.0.1:" + port + url);
f.channel().closeFuture().sync();
}finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
public static void main(String[] args) throws Exception {
int port = 8080;
if (args != null && args.length > 0) {
port = Integer.parseInt(args[0]);
}
String url = DEFAULT_URL;
if (args.length > 1) {
url = args[1];
}
new HttpFileServer().run(port,url);
}
}
HttpFileServerHandler.java
package club.wujingjian.com.wujingjian.netty.http;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.handler.codec.http.*;
import io.netty.handler.stream.ChunkedFile;
import io.netty.util.CharsetUtil;
import javax.activation.MimetypesFileTypeMap;
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 static io.netty.handler.codec.http.HttpHeaders.Names.*;
import static io.netty.handler.codec.http.HttpHeaders.Values.KEEP_ALIVE;
import static io.netty.handler.codec.http.HttpResponseStatus.*;
public class HttpFileServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
private final String url;
public HttpFileServerHandler(String url) {
this.url = url;
}
@Override
protected void messageReceived(ChannelHandlerContext ctx, FullHttpRequest fullHttpRequest) throws Exception {
//首先对HTTP请求消息的解码结果进行判断,如果解码失败,直接构造HTTP400错误返回
if (!fullHttpRequest.getDecoderResult().isSuccess()) {
sendError(ctx, BAD_REQUEST);
return;
}
//对请求行中的方法进行判断,如果不是GET请求则构造HTTP405 错误返回
if(fullHttpRequest.getMethod() != HttpMethod.GET) {
sendError(ctx, METHOD_NOT_ALLOWED);
return;
}
final String uri = fullHttpRequest.getUri();
final String path = sanitizeUri(uri); //校验url
if (path == null) {
sendError(ctx, FORBIDDEN);
return;
}
File file = new File(path);
//如果文件不存在或者是系统隐藏文件,则构造HTTP404异常返回
if (file.isHidden() || !file.exists()) {
sendError(ctx, NOT_FOUND);
return;
}
//如果文件是目录,则发送目录的链接给客户端浏览器
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 e) {
sendError(ctx, NOT_FOUND);
return;
}
long fileLength = randomAccessFile.length();
HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, OK);
setContentLength(response, fileLength);
setContentTypeHeader(response, file);
if (isKeepAlive(fullHttpRequest)) {
response.headers().set(CONNECTION, KEEP_ALIVE);
}
ctx.write(response);
ChannelFuture sendFileFuture;
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) throws Exception {
if (total < 0) {
System.err.println("Transfer progress: " + progress);
} else {
System.err.println("Transfer progress: " + progress + "/" + total);
}
}
@Override
public void operationComplete(ChannelProgressiveFuture channelProgressiveFuture) throws Exception {
System.out.println("Transfer complete");
}
});
ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
if (!isKeepAlive(fullHttpRequest)) {
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 {
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) {
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.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")
.append("<html><head><title>")
.append(dirPath)
.append(" 目录: ")
.append("</title></head><body>\r\n")
.append("<h3>")
.append(dirPath).append("目录: ")
.append("</h3>\r\n")
.append("<ul>")
.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=\"")
.append(name)
.append("\">")
.append(name)
.append("</a></li>\r\n");
}
buf.append("</ul></body></html>\r\n");
ByteBuf buffer = Unpooled.copiedBuffer(buf, CharsetUtil.UTF_8);
//将构造好的缓冲区中的响应消息存放到HTTP应答消息中
response.content().writeBytes(buffer);
//然后释放缓冲区
buffer.release();
//将响应消息发送到缓冲区并刷新到SocketChannel中
ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
}
private static void sendRedirect(ChannelHandlerContext ctx, String newUri) {
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.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(HttpVersion.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 mimetypesFileTypeMap = new MimetypesFileTypeMap();
response.headers().set(CONTENT_TYPE, mimetypesFileTypeMap.getContentType(file.getPath()));
}
private static void setContentLength(HttpResponse response,long length){
response.headers().set(CONTENT_LENGTH, length);
}
private static boolean isKeepAlive(FullHttpRequest fullHttpRequest) {
if(HttpHeaders.isKeepAlive(fullHttpRequest)){
return true;
}
return false;
}
}
运行效果:
注意:
单机某个文件可以进行下载了,之前不可以,是因为把下面的 DefaultHttpResponse 写成了 DefaultFullHttpResponse 了。
long fileLength = randomAccessFile.length();
HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, OK);
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