netty 实现tomcat的示例代码

netty 实现tomcat

自定义基础类

TomcatServlet

public abstract class TomcatServlet {

public void service(ServletRequest request, ServletResponse response){
if (\”GET\”.equalsIgnoreCase(request.getMethod())){
doGet(request, response);
}else if (\”POST\”.equalsIgnoreCase(request.getMethod())){
doPost(request, response);
}else {
doResponse(response, \”暂不支持其它请求方法\”);
}
}

public abstract void doGet(ServletRequest request, ServletResponse response);
public abstract void doPost(ServletRequest request, ServletResponse response);

public void doResponse(ServletResponse response, String message){
response.write(message);
}
}

ServletRequest

@Data
public class ServletRequest {

private ChannelHandlerContext context;
private HttpRequest httpRequest;

public ServletRequest(){

}

public ServletRequest(ChannelHandlerContext context, HttpRequest httpRequest){
this.context = context;
this.httpRequest = httpRequest;
}

public String getMethod(){
return httpRequest.method().name();
}

public HttpHeaders getHeaders(){
return httpRequest.headers();
}

public Map<String, List<String>> getParameters(){
QueryStringDecoder decoder = new QueryStringDecoder(httpRequest.uri());
return decoder.parameters();
}

public Map<String,String> getPostFormParameters(){
Map<String,String> params = new HashMap<>();

HttpPostRequestDecoder decoder = new HttpPostRequestDecoder(httpRequest);
decoder.getBodyHttpDatas().forEach(item -> {
if (item.getHttpDataType() == InterfaceHttpData.HttpDataType.Attribute){
Attribute attribute = (Attribute) item;

try {
String key = attribute.getName();
String value = attribute.getValue();

params.put(key, value);
}catch (Exception e){
e.printStackTrace();
}
}
});

return params;
}

public Map<String, Object> getPostBody(){
ByteBuf content = ((FullHttpRequest)httpRequest).content();
byte[] bytes = new byte[content.readableBytes()];
content.readBytes(bytes);

return JSON.parseObject(new String(bytes)).getInnerMap();
}
}

ServletResponse

@Data
public class ServletResponse {

private ChannelHandlerContext context;
private HttpRequest httpRequest;

public ServletResponse(){

}

public ServletResponse(ChannelHandlerContext context, HttpRequest httpRequest){
this.context = context;
this.httpRequest = httpRequest;
}

public void write(String message){
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
response.headers().set(\”Content-Type\”,\”application/json;charset=utf-8\”);
response.content().writeCharSequence(message, StandardCharsets.UTF_8);

context.channel().writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
}
}

CustomServlet

ublic class CustomServlet extends TomcatServlet{

@Override
public void doGet(ServletRequest request, ServletResponse response) {
System.out.println(\”处理GET请求\”);
System.out.println(\”请求参数为：\”);
request.getParameters().forEach((key,value) -> System.out.println(key + \” ==> \”+value));

doResponse(response, \”GET success\”);
}

@Override
public void doPost(ServletRequest request, ServletResponse response) {
if (request.getHeaders().get(\”Content-Type\”).contains(\”x-www-form-urlencoded\”)){
System.out.println(\”处理POST Form请求\”);
System.out.println(\”请求参数为：\”);
request.getPostFormParameters().forEach((key,value) -> System.out.println(key + \” ==> \” + value));

doResponse(response, \”POST Form success\”);
}else if (request.getHeaders().get(\”Content-Type\”).contains(\”application/json\”)){
System.out.println(\”处理POST json请求\”);
System.out.println(\”请求参数为：\”);
request.getPostBody().forEach((key,value) -> System.out.println(key + \” ==> \” + value));

doResponse(response, \”POST json success\”);
}else {
doResponse(response, \”error：暂不支持其它post请求方式\”);
}
}
}

ServletMapping：url与对应的TomcatServlet映射

public class ServletMapping {

private static final Map<String,TomcatServlet> urlServletMapping = new HashMap<>();

public static Map<String, TomcatServlet> getUrlServletMapping(){
return urlServletMapping;
}
}

web.properties：使用properties存储url与对应的TomcatServet

servlet.url=/hello
servlet.className=com.example.demo.tomcat.servlet.CustomServlet

netty 服务端

CustomServerHandler

public class CustomServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {

@Override
protected void channelRead0(ChannelHandlerContext channelHandlerContext, FullHttpRequest request) throws Exception {
String uri = request.uri();
String path = uri;
if (uri.contains(\”?\”)){
path = uri.substring(0,uri.indexOf(\”?\”));
}

if (ServletMapping.getUrlServletMapping().containsKey(path)){
ServletRequest servletRequest = new ServletRequest(channelHandlerContext, request);
ServletResponse servletResponse = new ServletResponse(channelHandlerContext, request);

ServletMapping.getUrlServletMapping().get(path).service(servletRequest, servletResponse);
}else {
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
response.content().writeCharSequence(\”404 NOT FOUND：\”+path+\”不存在\”, StandardCharsets.UTF_8);

channelHandlerContext.channel().writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
}
}
}

NettyServer

public class NettyServer {

private static final Properties webProperties = new Properties();

public static void init(){
try {
InputStream inputStream = new FileInputStream(\”./web.properties\”);
webProperties.load(inputStream);

for (Object item : webProperties.keySet()){
String key = (String)item;
if (key.endsWith(\”.url\”)){
String servletKey = key.replaceAll(\”\\\\.url\”,\”\\\\.className\”);
String servletName = webProperties.getProperty(servletKey);

TomcatServlet servlet = (TomcatServlet) Class.forName(servletName).newInstance();
ServletMapping.getUrlServletMapping().put(webProperties.getProperty(key),servlet);
}
}
}catch (Exception e){
e.printStackTrace();
}
}

public static void startServer(int port){
init();

EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();

try {
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.SO_KEEPALIVE, true)
.childHandler(new ChannelInitializer<SocketChannel>() {

@Override
protected void initChannel(SocketChannel socketChannel) throws Exception {
ChannelPipeline channelPipeline = socketChannel.pipeline();
channelPipeline.addLast(new HttpRequestDecoder());
channelPipeline.addLast(new HttpResponseEncoder());
channelPipeline.addLast(new HttpObjectAggregator(65535));
channelPipeline.addLast(new CustomServerHandler());
}
});

ChannelFuture channelFuture = serverBootstrap.bind(port).sync();
channelFuture.channel().closeFuture().sync();
}catch (Exception e){
e.printStackTrace();
}finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}

public static void main(String[] args) {
startServer(8000);
}
}