打造自己的web容器（2）

cwqcwq · 发表于 2013-2-7 20:15:09

---- 一个简单的web容器

上一篇对socket作了一下简单介绍，这一篇对其进行扩展，建立一个能够读取静态资源的web容器雏形。
由三个类完成：
Request：包装浏览器的请求
Response：包装服务器端的响应
HttpServer：HTTP服务器(接受请求，发送响应)

/** * 包装浏览器的请求 * @author chenwq */public class Request {private InputStream input;private String uri;public Request(InputStream input) {this.input = input;}public void parse() {// Read a set of characters from the socketStringBuffer request = new StringBuffer(2048);int i;byte[] buffer = new byte[2048];try {i = input.read(buffer);}catch (IOException e) {e.printStackTrace();i = -1;}for (int j = 0; j < i; j++) {request.append((char) buffer[j]);}uri = parseUri(request.toString());}private String parseUri(String requestString) {int index1, index2;index1 = requestString.indexOf(' ');if (index1 != -1) {index2 = requestString.indexOf(' ', index1 + 1);if (index2 > index1)return requestString.substring(index1 + 1, index2);}return null;}public String getUri() {return uri;}}

/** * 包装服务器端的响应 * @author chenwq */public class Response { private static final int BUFFER_SIZE = 1024;private Request request;private OutputStream output;public Response(OutputStream output) {this.output = output;}public void setRequest(Request request) {this.request = request;}public void sendStaticResource() throws IOException {byte[] bytes = new byte[BUFFER_SIZE];FileInputStream fis = null;try {//根据 parent 路径名字符串和 child 路径名字符串创建一个新 File 实例//child 路径名字符串用于表示目录或文件File file = new File(HttpServer.WEB_ROOT, request.getUri());if (file.exists()) {fis = new FileInputStream(file);int ch = fis.read(bytes, 0, BUFFER_SIZE);while (ch != -1) {output.write(bytes, 0, ch);ch = fis.read(bytes, 0, BUFFER_SIZE);}}else {// file not foundString errorMessage = "HTTP/1.1 404 File Not Found\r\n" + "Content-Type: text/html\r\n" + "Content-Length: 23\r\n" + "\r\n"+ "<h1>File Not Found</h1>";output.write(errorMessage.getBytes());}}catch (Exception e) {// thrown if cannot instantiate a File objectSystem.out.println(e.toString());}finally {if (fis != null)fis.close();}}}

/** * HTTP服务器(接受请求，发送响应) * @author chenwq */public class HttpServer {/* WEB应用的根目录 */public static final String WEB_ROOT = System.getProperty("user.dir") + File.separator + "WebContent";// shutdown commandprivate static final String SHUTDOWN_COMMAND = "/SHUTDOWN";// the shutdown command receivedprivate boolean shutdown = false;public static void main(String[] args) {HttpServer server = new HttpServer();server.await();}public void await() {ServerSocket serverSocket = null;int port = 8080;try {serverSocket = new ServerSocket(port, 1, InetAddress.getByName("127.0.0.1"));}catch (IOException e) {e.printStackTrace();System.exit(1);}// Loop waiting for a requestwhile (!shutdown) {Socket socket = null;InputStream input = null;OutputStream output = null;try {socket = serverSocket.accept();input = socket.getInputStream();output = socket.getOutputStream();// create Request object and parseRequest request = new Request(input);request.parse();// create Response objectResponse response = new Response(output);response.setRequest(request);response.sendStaticResource();// Close the socketsocket.close();//check if the previous URI is a shutdown commandshutdown = request.getUri().equals(SHUTDOWN_COMMAND);}catch (Exception e) {e.printStackTrace();continue;}}}}

测试页面：index.html，该页面位于 ${user.dir}/WebContent/ 下

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><h1> Hello! MyWebContainer </h1></body></html>

运行HttpServer，启动容器，在浏览器中键入：http://localhost:8080/index.html，得到如下反馈：

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