Java web server 基本實現原理
public class WebServer { //服務端Socket只要一個,所以定義成static, 同一時間只能一個線程訪問(主線程) private static ServerSocket ss; public static void main(String[] args) throws IOException { //綁定端口,只會執行一次 ss = new ServerSocket(8999); //遠端服務器使用ServerSocket技術打開一個端口,等待請求的到來
//主線程永遠不死,所以用了個死循環 while(true) { //這是一個IO阻塞式語句,也就是如果沒有請求(IO操作)進來,當前線程會在此等待,不再向下執行 Socket socket = ss.accept(); // socket:(本機IP+ 本機端口 +服務端IP+ 服務端端口,用來唯一標示一條TCP聯接)通道
//得到請求報文(內容) StringBuffer sb = new StringBuffer(); PrintWriter pw = null; try { InputStream socketIn= socket.getInputStream(); //從通道socket上獲得流 BufferedReader br = new BufferedReader(new InputStreamReader(socketIn)); while(true) { String msg = br.readLine(); sb.append(msg); System.out.println(msg);if (msg == null || msg.trim().equals("")) { break; } } //輸入響應報文 pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8")); // 所發送HTTP數據包
pw.println("HTTP/1.1 200 OK"); pw.println("Content-Type: text/html;charset=UTF-8"); pw.println(); pw.write("html"); pw.flush(); } catch (IOException exception) { //TODO 處理異常 } finally { socket.close(); pw.close(); //socket = null; } } } }
servlet 是單例的 只初始化一次
可以在Web.xml中配置
<init-param> <param-name></param-name> <param-value></param-value> </init-param>
然後在servlet的init函數中獲得參數
config.getInitParameter();
publicclass WebServer {
//服務端Socket只要一個,所以定義成static, 同一時間只能一個線程訪問(主線程)
privatestatic ServerSocket ss;
publicstaticvoid main(String[] args) throws IOException {
//綁定端口,只會執行一次
ss = new ServerSocket(8999);
//主線程永遠不死,所以用了個死循環
while (true) {
//這是一個IO阻塞式語句,也就是如果沒有請求(IO操作)進來,當前線程會在此等待,不再向下執行
Socket socket = ss.accept();
//得到請求報文(內容)
StringBuffer sb = new StringBuffer();
PrintWriter pw = null;
try {
InputStream socketIn = socket.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(socketIn));
while(true) {
String msg = br.readLine();
sb.append(msg);
System.out.println(msg);
if (msg == null || msg.trim().equals("")) {
break;
}
}
//輸入響應報文
pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8"));
pw.println("HTTP/1.1 200 OK");
pw.println("Content-Type: text/html;charset=UTF-8");
pw.println();
pw.write("html");
pw.flush();
} catch (IOException exception) {
//TODO處理異常
} finally {
socket.close();
pw.close();
//socket = null;
}
}
}
}
Java web server 基本實現原理