[JavaScript知识库]基于netty实现简易版的tomcat服务器

运行效果图:

servlet url配置信息保存在application.properties中，通过解析得到对应的url与方法的映射，并保存到内存中去,基于netty实现访问:代码如下

public void init() throws FileNotFoundException {
String basePath = this.getClass().getResource("/").getPath() ;
FileInputStream ins = new FileInputStream(new File(basePath + “application.properties”)) ;
try {
prop.load(ins);
for (Object obj : prop.keySet()){
String key = trimToEmpty(obj) ;
String property = prop.getProperty(key);
if (key.endsWith(".port")){
if (!(property == “” || property == null)){
this.port = Integer.parseInt(property) ;
}
}
if (key.endsWith(".url")) {
Class clazz = Class.forName(prop.getProperty(key.replaceAll("\.url$",".className"))) ;
Constructor constructor = clazz.getDeclaredConstructor();
if (!constructor.isAccessible()){
constructor.setAccessible(true);
}
urlMapping.put(property,(EasyServlet) constructor.newInstance()) ;
}
}

    if (this.port <= 0){
        this.port = 8080 ;
    }
} catch (Exception e) {
    e.printStackTrace();
}

}
处理器类:

public class EasyTomcatHandler extends ChannelInboundHandlerAdapter {

private Map<String,EasyServlet> urlMapping ;

public EasyTomcatHandler(Map<String, EasyServlet> mapping){
    this.urlMapping = mapping ;
}

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
   if (msg instanceof HttpRequest){
       HttpRequest req = (HttpRequest) msg;

       EasyRequest request = new EasyRequest(ctx,req) ;
       EasyResponse response = new EasyResponse(ctx,req) ;

       String url = request.getUrl();
       if (urlMapping.containsKey(url)){
           EasyServlet servlet = urlMapping.get(url) ;
           servlet.service(request,response);
       }
   }
}

}
当接收到请求的时候队请求进行处理

netty服务端代码：

**

• @Author: drainli
  **/
  public class EasyApplication {

  private int port ;

  Map<String, EasyServlet> urlMapping = new HashMap<>() ;
  Properties prop = new Properties() ;

  public static void main(String[] args) throws InterruptedException {
  new EasyApplication().startUp();
  }

  public void startUp() throws InterruptedException {

   try {
       init();
   } catch (FileNotFoundException e) {
       e.printStackTrace();
   }
  
   ServerBootstrap bootstrap = new ServerBootstrap() ;
  
   EventLoopGroup boss = new NioEventLoopGroup() ;
   EventLoopGroup works = new NioEventLoopGroup() ;
  
   bootstrap.group(boss,works)
           .channel(NioServerSocketChannel.class)
           .childHandler(new ChannelInitializer<>() {
               @Override
               protected void initChannel(Channel ch) throws Exception {
                   ch.pipeline().addLast(new HttpResponseEncoder())
                                   .addLast(new HttpRequestDecoder())
                                   .addLast(new EasyTomcatHandler(urlMapping)) ;
               }
           })
           .option(ChannelOption.SO_BACKLOG,128)
           .childOption(ChannelOption.SO_KEEPALIVE,true) ;
  
   ChannelFuture sync = bootstrap.bind(port).sync();
  
   System.out.printf("server has startup,the listening port is :%d%n",port);
  
   sync.channel().closeFuture().sync() ;
  
   boss.shutdownGracefully() ;
   works.shutdownGracefully() ;
  

  }

  public void init() throws FileNotFoundException {
  String basePath = this.getClass().getResource("/").getPath() ;
  FileInputStream ins = new FileInputStream(new File(basePath + “application.properties”)) ;
  try {
  prop.load(ins);
  for (Object obj : prop.keySet()){
  String key = trimToEmpty(obj) ;
  String property = prop.getProperty(key);
  if (key.endsWith(".port")){
  if (!(property == “” || property == null)){
  this.port = Integer.parseInt(property) ;
  }
  }
  if (key.endsWith(".url")) {
  Class clazz = Class.forName(prop.getProperty(key.replaceAll("\.url$",".className"))) ;
  Constructor constructor = clazz.getDeclaredConstructor();
  if (!constructor.isAccessible()){
  constructor.setAccessible(true);
  }
  urlMapping.put(property,(EasyServlet) constructor.newInstance()) ;
  }
  }

       if (this.port <= 0){
           this.port = 8080 ;
       }
   } catch (Exception e) {
       e.printStackTrace();
   }
  

  }

  private String trimToEmpty(Object obj){
  return obj == null ? “” : String.valueOf(obj).trim() ;
  }
  }
  访问 firstservlet.do接口时的效果图:

完整代码地址: https://gitee.com/drainli/easy-tomcat