Server

• Server是配置檔案中的頂層，一個Server代表的就是一個伺服器，在整個學習Tomcat內建物件的過程中，同意的做法都是藉助ServerXmlUtil這個類來將配置檔案中的資訊解析出來並構建物件，對映到類的例項當中。

• Server類和上面的幾個類的改動不太一樣，因為已經說了Server代表的是伺服器，那麼在Bootstrap中的服務啟動和相應請求這些功能都應當放在Server中更為合理。

• 建立server類

  • package jerrymice.catalina;
    
    import cn.hutool.core.io.FileUtil;
    import cn.hutool.core.thread.ThreadUtil;
    import cn.hutool.core.util.ArrayUtil;
    import cn.hutool.core.util.StrUtil;
    import cn.hutool.log.LogFactory;
    import cn.hutool.system.SystemUtil;
    import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
    import jerrymice.http.Request;
    import jerrymice.http.Response;
    import jerrymice.util.Constant;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.nio.charset.StandardCharsets;
    import java.util.LinkedHashMap;
    import java.util.Map;
    import java.util.Set;
    
    /**
     * @author ：xiaosong
     * @description：TODO
     * @date ：2020/8/5 14:06
     */
    public class Server {
        private Service service;
        public Server(){
            this.service = new Service(this);
        }
    
        public void start(){
            logJvm();
            init();
        }
        private void logJvm() {
            // 建立一個Map用於儲存各種資訊
            Map<String, String> infoMap = new LinkedHashMap<>();
            infoMap.put("Server version", "JerryMice 1.0.0");
            infoMap.put("Server build", "2020-08-03");
            infoMap.put("OS:\t", SystemUtil.get("os.name"));
            infoMap.put("OS version", SystemUtil.get("os.version"));
            infoMap.put("Architecture", SystemUtil.get("os.arch"));
            infoMap.put("Java Home", SystemUtil.get("java.home"));
            infoMap.put("JSM Version", SystemUtil.get("java.runtime.version"));
            infoMap.put("JVM Vendor", SystemUtil.get("java.vm.specification.vendor"));
            Set<String> keys = infoMap.keySet();
            for (String key : keys) {
                // 呼叫hutool的LogFactory工廠函式獲取logger，logger會自動根據log4j.properties來對Log4j的Logger進行配置
                LogFactory.get().info(key + ":\t\t" + infoMap.get(key));
            }
        }
    
        @SuppressWarnings("InfiniteLoopStatement")
        private void init(){
            try {
                int port = 10086;
                ServerSocket serverSocket = new ServerSocket(port);
    
                while (true) {
                    Socket socket = serverSocket.accept();
                    Runnable runnable = () -> {
                        try {
                            Request request = new Request(socket, service);
                            Response response = new Response();
                            String uri = request.getUri();
                            if (null == uri){
                                return;
                            }
                            System.out.println("uri:" + uri);
                            Context context = request.getContext();
                            if ("/".equals(uri)) {
                                String html = "Hello, JerryMice";
                                response.getWriter().println(html);
                            }
                            else {
                                String fileName = StrUtil.removePrefix(uri, "/");
                                File file = FileUtil.file(context.getDocBase(), fileName);
                                if (file.exists()) {
                                    String fileContent = FileUtil.readUtf8String(file);
                                    response.getWriter().println(fileContent);
    
                                    if ("timeConsume.html".equals(fileName)) {
                                        ThreadUtil.sleep(1000);
                                    }
                                }
                                else {
                                    // 訪問檔案不存在的情況下
                                    handle404(socket, uri);
                                    return;
                                }
                            }
                            handle200(socket, response);
                        }catch (IOException e) {
                            LogFactory.get().info(e);
                        }finally {
                            // 將socket的關閉提取到最後，因為無論是200的響應還是404的響應都需要關閉socket
                            try {
                                socket.close();
                            }catch (IOException e){
                                LogFactory.get().info(e);
                            }
                        }
                    };
                    jerrymice.util.ThreadUtil.run(runnable);
                }
            }catch (IOException e) {
                LogFactory.get().info(e);
            }
        }
        private static void handle200(Socket socket, Response response) throws IOException {
            // 獲取型別
            String contentType = response.getContentType();
            String headText = Constant.responseHead200;
            headText = StrUtil.format(headText, contentType);
            byte[] head = headText.getBytes();
            // 獲取response中的html文字，這個html文字是通過writer寫到stringWriter字元流上的
            byte[] body = response.getBody();
            byte[] responseBytes = new byte[head.length + body.length];
            ArrayUtil.copy(head, 0, responseBytes, 0, head.length);
            ArrayUtil.copy(body, 0, responseBytes, head.length, body.length);
    
            OutputStream outputStream = socket.getOutputStream();
            outputStream.write(responseBytes);
        }
    }
     
    

• 將與啟動服務的方法都移動到server類中之後，Bootstrap變得異常簡潔。

  • public class Bootstrap {
        public static void main(String[] args) {
            Server server = new Server();
            server.start();
        }
    }