## 一、 Netty是怎么做文件上传
## 服务器编写
public final class HttpUploadServer {
static final boolean SSL = System.getProperty("ssl") != null;
static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8443" : "8080"));
public static void main(String[] args) throws Exception {
// Configure SSL.
final SslContext sslCtx;
if (SSL) {
SelfSignedCertificate ssc = new SelfSignedCertificate();
sslCtx = SslContext.newServerContext(ssc.certificate(), ssc.privateKey());
} else {
sslCtx = null;
}
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup);
b.channel(NioServerSocketChannel.class);
b.handler(new LoggingHandler(LogLevel.INFO));
b.childHandler(new HttpUploadServerInitializer(sslCtx));
Channel ch = b.bind(PORT).sync().channel();
System.err.println("Open your web browser and navigate to " +
(SSL? "https" : "http") + "://127.0.0.1:" + PORT + '/');
ch.closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
## 总结
一、 System.getProperty("ssl") 主要输获取系统的jvm的参数
二、 Netty中 SelfSignedCertificate
三、 b.handler(new LoggingHandler(LogLevel.INFO)); 加入日志处理
## 二 、HttpUploadServerInitializer
public class HttpUploadServerInitializer extends ChannelInitializer<SocketChannel> {
private final SslContext sslCtx;
public HttpUploadServerInitializer(SslContext sslCtx) {
this.sslCtx = sslCtx;
}
@Override
public void initChannel(SocketChannel ch) {
ChannelPipeline pipeline = ch.pipeline();
if (sslCtx != null) {
pipeline.addLast(sslCtx.newHandler(ch.alloc()));
}
pipeline.addLast(new HttpRequestDecoder());
pipeline.addLast(new HttpResponseEncoder());
// Remove the following line if you don't want automatic content compression.
pipeline.addLast(new HttpContentCompressor());
pipeline.addLast(new HttpUploadServerHandler());
}
}
### 总结：
一、ChannelInitializer 表示在管道里面添加信息
二、ByteBufAllocator体系的里面的Netty源码架构的解说
1.架构图
ByteBufAllocator 接口
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AbstractByteAllocator
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——————————————
UnpooledByteBufAllocatior PooledByteBufAllocator
ByteBufAllocator主要用来生成三种ByteBuf :HeadBuffer,DirectBuffer,CompositeBuffer. 还有一个 ByteBufAllocator DEFAULT 静态属性。 我们可以通过io.netty.allocator.type来控制该静态属性的类型：unpooled和pooled （是否使用缓冲池）。
用于ByteBuf是通过引用计数来管理内存。在AbstractByteBufAllocator引用了一个toLeakAwareBuffer方法帮助分析内存是否泄漏 。具体参考http://blog.csdn.net/damacheng/article/details/42393757
netty根据是否使用缓存池提供了两个实现类。UnpooledByteBufAllocator和PooledByteBufAllocator（这个比较复杂，实现了jemalloc的算法）
UnpooledByteBufAllocator根据使用使用sun.misc.Unsafe类提供了两种直接缓存
UnpooledUnsafeDirectByteBuf和UnpooledDirectByteBuf 一个使用unsafe来对直接缓冲区进行操作，一个使用 bytebuffer的方法对缓冲区进行操作。
## 三、HttpUploadServerInitializer
public class HttpUploadServerHandler extends SimpleChannelInboundHandler<HttpObject> {
private static final Logger logger = Logger.getLogger(HttpUploadServerHandler.class.getName());
private HttpRequest request;
private boolean readingChunks;
private final StringBuilder responseContent = new StringBuilder();
private static final HttpDataFactory factory =
new DefaultHttpDataFactory(DefaultHttpDataFactory.MINSIZE); // Disk if size exceed
private HttpPostRequestDecoder decoder;
static {
DiskFileUpload.deleteOnExitTemporaryFile = true; // should delete file// on exit (in normal// exit)
DiskFileUpload.baseDirectory = "E:" + File.separatorChar + "aa"; // system temp directory
DiskAttribute.deleteOnExitTemporaryFile = true; // should delete file o// exit (in normal exit)
DiskAttribute.baseDirectory = "E:" + File.separatorChar + "aa"; // system temp directory
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
if (decoder != null) {
decoder.cleanFiles();
}
}
@Override
public void messageReceived(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
if (msg instanceof HttpRequest) {
HttpRequest request = this.request = (HttpRequest) msg;
URI uri = new URI(request.uri());
if (!uri.getPath().startsWith("/form")) {
// Write Menu
writeMenu(ctx);
return;
}
responseContent.setLength(0);
responseContent.append("WELCOME TO THE WILD WILD WEB SERVER\r\n");
responseContent.append("===================================\r\n");
responseContent.append("VERSION: " + request.protocolVersion().text() + "\r\n");
responseContent.append("REQUEST_URI: " + request.uri() + "\r\n\r\n");
responseContent.append("\r\n\r\n");
// new getMethod
for (Entry<CharSequence, CharSequence> entry : request.headers()) {
responseContent.append("HEADER: " + entry.getKey() + '=' + entry.getValue() + "\r\n");
}
responseContent.append("\r\n\r\n");
// new getMethod
Set<Cookie> cookies;
String value = request.headers().getAndConvert(HttpHeaderNames.COOKIE);
if (value == null) {
cookies = Collections.emptySet();
} else {
cookies = ServerCookieDecoder.decode(value);
}
for (Cookie cookie : cookies) {
responseContent.append("COOKIE: " + cookie + "\r\n");
}
responseContent.append("\r\n\r\n");
QueryStringDecoder decoderQuery = new QueryStringDecoder(request.uri());
Map<String, List<String>> uriAttributes = decoderQuery.parameters();
for (Entry<String, List<String>> attr: uriAttributes.entrySet()) {
for (String attrVal: attr.getValue()) {
responseContent.append("URI: " + attr.getKey() + '=' + attrVal + "\r\n");
}
}
responseContent.append("\r\n\r\n");
// if GET Method: should not try to create a HttpPostRequestDecoder
if (request.method().equals(HttpMethod.GET)) {
// GET Method: should not try to create a HttpPostRequestDecoder
// So stop here
responseContent.append("\r\n\r\nEND OF GET CONTENT\r\n");
// Not now: LastHttpContent will be sent writeResponse(ctx.channel());
return;
}
try {
decoder = new HttpPostRequestDecoder(factory, request);
} catch (ErrorDataDecoderException e1) {
e1.printStackTrace();
responseContent.append(e1.getMessage());
writeResponse(ctx.channel());
ctx.channel().close();
return;
}
readingChunks = HttpHeaderUtil.isTransferEncodingChunked(request);
responseContent.append("Is Chunked: " + readingChunks + "\r\n");
responseContent.append("IsMultipart: " + decoder.isMultipart() + "\r\n");
if (readingChunks) {
// Chunk version
responseContent.append("Chunks: ");
readingChunks = true;
}
}
// check if the decoder was constructed before
// if not it handles the form get
if (decoder != null) {
if (msg instanceof HttpContent) {
// New chunk is received
HttpContent chunk = (HttpContent) msg;
try {
decoder.offer(chunk);
} catch (ErrorDataDecoderException e1) {
e1.printStackTrace();
responseContent.append(e1.getMessage());
writeResponse(ctx.channel());
ctx.channel().close();
return;
}
responseContent.append('o');
// example of reading chunk by chunk (minimize memory usage due to
// Factory)
readHttpDataChunkByChunk();
// example of reading only if at the end
if (chunk instanceof LastHttpContent) {
writeResponse(ctx.channel());
readingChunks = false;
reset();
}
}
} else {
writeResponse(ctx.channel());
}
}
private void reset() {
request = null;
// destroy the decoder to release all resources
decoder.destroy();
decoder = null;
}
/**
* Example of reading request by chunk and getting values from chunk to chunk
*/
private void readHttpDataChunkByChunk() throws Exception {
try {
while (decoder.hasNext()) {
InterfaceHttpData data = decoder.next();
if (data != null) {
try {
// new value
writeHttpData(data);
} finally {
data.release();
}
}
}
} catch (EndOfDataDecoderException e1) {
// end
responseContent.append("\r\n\r\nEND OF CONTENT CHUNK BY CHUNK\r\n\r\n");
}
}
### 这个方法主要用于上传文件的信息
private void writeHttpData(InterfaceHttpData data) throws Exception {
if (data.getHttpDataType() == HttpDataType.Attribute) {
Attribute attribute = (Attribute) data;
String value;
try {
value = attribute.getValue();
} catch (IOException e1) {
// Error while reading data from File, only print name and error
e1.printStackTrace();
responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
+ attribute.getName() + " Error while reading value: " + e1.getMessage() + "\r\n");
return;
}
if (value.length() > 100) {
responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
+ attribute.getName() + " data too long\r\n");
} else {
responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ": "
+ attribute + "\r\n");
}
} else {
responseContent.append("\r\n -----------start-------------" + "\r\n");
responseContent.append("\r\nBODY FileUpload: " + data.getHttpDataType().name() + ": " + data
+ "\r\n");
responseContent.append("\r\n ------------end------------" + "\r\n");
if (data.getHttpDataType() == HttpDataType.FileUpload) {
FileUpload fileUpload = (FileUpload) data;
if (fileUpload.isCompleted()) {
System.out.println("file name : " + fileUpload.getFilename());
System.out.println("file length: " + fileUpload.length());
System.out.println("file maxSize : " + fileUpload.getMaxSize());
// System.out.println("file path :" + fileUpload.getFile().getPath());
// System.out.println("file absolutepath :" + fileUpload.getFile().getAbsolutePath());
// System.out.println("parent path :" + fileUpload.getFile().getParentFile());
if (fileUpload.length() < 1024*1024*10) {
responseContent.append("\tContent of file\r\n");
try {
//responseContent.append(fileUpload.getString(fileUpload.getCharset()));
} catch (Exception e1) {
// do nothing for the example
e1.printStackTrace();
}
responseContent.append("\r\n");
} else {
responseContent.append("\tFile too long to be printed out:" + fileUpload.length() + "\r\n");
}
// fileUpload.isInMemory();// tells if the file is in Memory
// or on File
fileUpload.renameTo(new File(fileUpload.getFile().getPath())); // enable to move into another
// File dest
//decoder.removeFileUploadFromClean(fileUpload); //remove
// the File of to delete file
} else {
responseContent.append("\tFile to be continued but should not!\r\n");
}
}
}
}
private void writeResponse(Channel channel) {
// Convert the response content to a ChannelBuffer.
ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);
responseContent.setLength(0);
// Decide whether to close the connection or not.
boolean close = request.headers().contains(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE, true)
|| request.protocolVersion().equals(HttpVersion.HTTP_1_0)
&& !request.headers().contains(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE, true);
// Build the response object.
FullHttpResponse response = new DefaultFullHttpResponse(
HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=UTF-8");
if (!close) {
// There's no need to add 'Content-Length' header
// if this is the last response.
response.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, buf.readableBytes());
}
Set<Cookie> cookies;
String value = request.headers().getAndConvert(HttpHeaderNames.COOKIE);
if (value == null) {
cookies = Collections.emptySet();
} else {
cookies = ServerCookieDecoder.decode(value);
}
if (!cookies.isEmpty()) {
// Reset the cookies if necessary.
for (Cookie cookie : cookies) {
response.headers().add(HttpHeaderNames.SET_COOKIE, ServerCookieEncoder.encode(cookie));
}
}
// Write the response.
ChannelFuture future = channel.writeAndFlush(response);
// Close the connection after the write operation is done if necessary.
if (close) {
future.addListener(ChannelFutureListener.CLOSE);
}
}
private void writeMenu(ChannelHandlerContext ctx) {
// print several HTML forms
// Convert the response content to a ChannelBuffer.
responseContent.setLength(0);
// create Pseudo Menu
responseContent.append("<html>");
responseContent.append("<head>");
responseContent.append("<title>Netty Test Form</title>\r\n");
responseContent.append("</head>\r\n");
responseContent.append("<body bgcolor=white><style>td{font-size: 12pt;}</style>");
responseContent.append("<table border=\"0\">");
responseContent.append("<tr>");
responseContent.append("<td>");
responseContent.append("<h1>Netty Test Form</h1>");
responseContent.append("Choose one FORM");
responseContent.append("</td>");
responseContent.append("</tr>");
responseContent.append("</table>\r\n");
// GET
responseContent.append("<CENTER>GET FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
responseContent.append("<FORM ACTION=\"/formget\" METHOD=\"GET\">");
responseContent.append("<input type=hidden name=getform value=\"GET\">");
responseContent.append("<table border=\"0\">");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
responseContent
.append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
responseContent.append("</td></tr>");
responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
responseContent.append("</table></FORM>\r\n");
responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
// POST
responseContent.append("<CENTER>POST FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
responseContent.append("<FORM ACTION=\"/formpost\" METHOD=\"POST\">");
responseContent.append("<input type=hidden name=getform value=\"POST\">");
responseContent.append("<table border=\"0\">");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
responseContent
.append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
responseContent.append("<tr><td>Fill with file (only file name will be transmitted): <br> "
+ "<input type=file name=\"myfile\">");
responseContent.append("</td></tr>");
responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
responseContent.append("</table></FORM>\r\n");
responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
// POST with enctype="multipart/form-data"
responseContent.append("<CENTER>POST MULTIPART FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
responseContent.append("<FORM ACTION=\"/formpostmultipart\" ENCTYPE=\"multipart/form-data\" METHOD=\"POST\">");
responseContent.append("<input type=hidden name=getform value=\"POST\">");
responseContent.append("<table border=\"0\">");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");
responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");
responseContent
.append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");
responseContent.append("<tr><td>Fill with file: <br> <input type=file name=\"myfile\">");
responseContent.append("</td></tr>");
responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");
responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");
responseContent.append("</table></FORM>\r\n");
responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");
responseContent.append("</body>");
responseContent.append("</html>");
ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);
// Build the response object.
FullHttpResponse response = new DefaultFullHttpResponse(
HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/html; charset=UTF-8");
response.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, buf.readableBytes());
// Write the response.
ctx.channel().writeAndFlush(response);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.log(Level.WARNING, responseContent.toString(), cause);
ctx.channel().close();
}
}
### 总结
一、ChannelInitializer 这个类前面第四节详细说了这个类的使用
channelInactive ：在客户端来接服务器是否调用
messageReceived：收到信息的时候调用
exceptionCaught：异常的是否调用
