package cn.how2j.diytomcat.util; import java.io.*; import java.net.InetSocketAddress; import java.net.Socket; import java.net.URL; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.Set; import cn.hutool.core.convert.Convert; import cn.hutool.core.util.ZipUtil; import cn.hutool.http.HttpUtil; public class MiniBrowser { public static void main(String[] args) throws Exception { String url = "http://static.how2j.cn/diytomcat.html"; String contentString= getContentString(url,false); System.out.println(contentString); String httpString= getHttpString(url,false); System.out.println(httpString); } public static byte[] getContentBytes(String url) { return getContentBytes(url, false); } public static String getContentString(String url) { return getContentString(url,false); } public static String getContentString(String url, boolean gzip) { byte[] result = getContentBytes(url, gzip); if(null==result) return null; try { return new String(result,"utf-8").trim(); } catch (UnsupportedEncodingException e) { return null; } } public static byte[] getContentBytes(String url, boolean gzip) { byte[] response = getHttpBytes(url,gzip); byte[] doubleReturn = "\r\n\r\n".getBytes(); int pos = -1; for (int i = 0; i < response.length-doubleReturn.length; i++) { byte[] temp = Arrays.copyOfRange(response, i, i + doubleReturn.length); if(Arrays.equals(temp, doubleReturn)) { pos = i; break; } } if(-1==pos) return null; pos += doubleReturn.length; byte[] result = Arrays.copyOfRange(response, pos, response.length); return result; } public static String getHttpString(String url,boolean gzip) { byte[] bytes=getHttpBytes(url,gzip); return new String(bytes).trim(); } public static String getHttpString(String url) { return getHttpString(url,false); } public static byte[] getHttpBytes(String url,boolean gzip) { byte[] result = null; try { URL u = new URL(url); Socket client = new Socket(); int port = u.getPort(); if(-1==port) port = 80; InetSocketAddress inetSocketAddress = new InetSocketAddress(u.getHost(), port); client.connect(inetSocketAddress, 1000); Map<String,String> requestHeaders = new HashMap<>(); requestHeaders.put("Host", u.getHost()+":"+port); requestHeaders.put("Accept", "text/html"); requestHeaders.put("Connection", "close"); requestHeaders.put("User-Agent", "how2j mini brower / java1.8"); if(gzip) requestHeaders.put("Accept-Encoding", "gzip"); String path = u.getPath(); if(path.length()==0) path = "/"; String firstLine = "GET " + path + " HTTP/1.1\r\n"; StringBuffer httpRequestString = new StringBuffer(); httpRequestString.append(firstLine); Set<String> headers = requestHeaders.keySet(); for (String header : headers) { String headerLine = header + ":" + requestHeaders.get(header)+"\r\n"; httpRequestString.append(headerLine); } PrintWriter pWriter = new PrintWriter(client.getOutputStream(), true); pWriter.println(httpRequestString); InputStream is = client.getInputStream(); result = readBytes(is); client.close(); } catch (Exception e) { e.printStackTrace(); try { result = e.toString().getBytes("utf-8"); } catch (UnsupportedEncodingException e1) { e1.printStackTrace(); } } return result; } public static byte[] readBytes(InputStream is) throws IOException { int buffer_size = 1024; byte buffer[] = new byte[buffer_size]; ByteArrayOutputStream baos = new ByteArrayOutputStream(); while(true) { int length = is.read(buffer); if(-1==length) break; baos.write(buffer, 0, length); if(length!=buffer_size) break; } byte[] result =baos.toByteArray(); return result; } }

package cn.how2j.diytomcat.http; import cn.how2j.diytomcat.util.MiniBrowser; import cn.hutool.core.util.StrUtil; import java.io.IOException; import java.io.InputStream; import java.net.Socket; public class Request { private String requestString; private String uri; private Socket socket; public Request(Socket socket) throws IOException { this.socket = socket; parseHttpRequest(); if(StrUtil.isEmpty(requestString)) return; parseUri(); } private void parseHttpRequest() throws IOException { InputStream is = this.socket.getInputStream(); byte[] bytes = MiniBrowser.readBytes(is); requestString = new String(bytes, "utf-8"); } private void parseUri() { String temp; temp = StrUtil.subBetween(requestString, " ", " "); if (!StrUtil.contains(temp, '?')) { uri = temp; return; } temp = StrUtil.subBefore(temp, '?', false); uri = temp; } public String getUri() { return uri; } public String getRequestString(){ return requestString; } }

package cn.how2j.diytomcat; import cn.how2j.diytomcat.http.Request; import cn.hutool.core.util.NetUtil; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; public class Bootstrap { public static void main(String[] args) { try { int port = 18080; if(!NetUtil.isUsableLocalPort(port)) { System.out.println(port +" 端口已经被占用了，排查并关闭本端口的办法请用：\r\nhttps://how2j.cn/k/tomcat/tomcat-portfix/545.html"); return; } ServerSocket ss = new ServerSocket(port); while(true) { Socket s = ss.accept(); Request request = new Request(s); System.out.println("浏览器的输入信息： \r\n" + request.getRequestString()); System.out.println("uri:" + request.getUri()); OutputStream os = s.getOutputStream(); String response_head = "HTTP/1.1 200 OK\r\n" + "Content-Type: text/html\r\n\r\n"; String responseString = "Hello DIY Tomcat from how2j.cn"; responseString = response_head + responseString; os.write(responseString.getBytes()); os.flush(); s.close(); } } catch (IOException e) { e.printStackTrace(); } } }