tomcat2章1
package ex02.pyrmont; import java.io.File; public class Constants { public static final String WEB_ROOT = System.getProperty("user.dir") + File.separator + "webroot"; }
package ex02.pyrmont; import java.net.Socket; import java.net.ServerSocket; import java.net.InetAddress; import java.io.InputStream; import java.io.OutputStream; import java.io.IOException; public class HttpServer1 { private static final String SHUTDOWN_COMMAND = "/SHUTDOWN"; private boolean shutdown = false; public static void main(String[] args) { HttpServer1 server = new HttpServer1(); 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); } while (!shutdown) { Socket socket = null; InputStream input = null; OutputStream output = null; try { socket = serverSocket.accept(); input = socket.getInputStream(); output = socket.getOutputStream(); Request request = new Request(input); request.parse(); Response response = new Response(output); response.setRequest(request); // a request for a servlet begins with "/servlet/" if (request.getUri().startsWith("/servlet/")) { ServletProcessor1 processor = new ServletProcessor1(); processor.process(request, response); //根据url后面的参数 找到servlet去处理 } else {//处理页面等资源 StaticResourceProcessor processor = new StaticResourceProcessor(); processor.process(request, response); } socket.close(); shutdown = request.getUri().equals(SHUTDOWN_COMMAND); } catch (Exception e) { e.printStackTrace(); System.exit(1); } } } }
package ex02.pyrmont; import java.io.InputStream; import java.io.IOException; import java.io.BufferedReader; import java.io.UnsupportedEncodingException; import java.util.Enumeration; import java.util.Locale; import java.util.Map; import javax.servlet.RequestDispatcher; import javax.servlet.ServletInputStream; import javax.servlet.ServletRequest; public class Request implements ServletRequest { private InputStream input; private String uri; public Request(InputStream input) { this.input = input; } public String getUri() { return uri; } 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 void parse() { StringBuffer 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]); } System.out.print(request.toString()); uri = parseUri(request.toString()); } /* implementation of the ServletRequest*/ public Object getAttribute(String attribute) { return null; } public Enumeration getAttributeNames() { return null; } public String getRealPath(String path) { return null; } public RequestDispatcher getRequestDispatcher(String path) { return null; } public boolean isSecure() { return false; } public String getCharacterEncoding() { return null; } public int getContentLength() { return 0; } public String getContentType() { return null; } public ServletInputStream getInputStream() throws IOException { return null; } public Locale getLocale() { return null; } public Enumeration getLocales() { return null; } public String getParameter(String name) { return null; } public Map getParameterMap() { return null; } public Enumeration getParameterNames() { return null; } public String[] getParameterValues(String parameter) { return null; } public String getProtocol() { return null; } public BufferedReader getReader() throws IOException { return null; } public String getRemoteAddr() { return null; } public String getRemoteHost() { return null; } public String getScheme() { return null; } public String getServerName() { return null; } public int getServerPort() { return 0; } public void removeAttribute(String attribute) { } public void setAttribute(String key, Object value) { } public void setCharacterEncoding(String encoding) throws UnsupportedEncodingException { } }
package ex02.pyrmont; import java.io.OutputStream; import java.io.IOException; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.File; import java.io.PrintWriter; import java.util.Locale; import javax.servlet.ServletResponse; import javax.servlet.ServletOutputStream; public class Response implements ServletResponse { private static final int BUFFER_SIZE = 1024; Request request; OutputStream output; PrintWriter writer; 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 { /* request.getUri has been replaced by request.getRequestURI */ File file = new File(Constants.WEB_ROOT, request.getUri()); fis = new FileInputStream(file); /* HTTP Response = Status-Line *(( general-header | response-header | entity-header ) CRLF) CRLF [ message-body ] Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF */ int ch = fis.read(bytes, 0, BUFFER_SIZE); while (ch!=-1) { output.write(bytes, 0, ch); ch = fis.read(bytes, 0, BUFFER_SIZE); } } catch (FileNotFoundException e) { String 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()); } finally { if (fis!=null) fis.close(); } } /** implementation of ServletResponse */ public void flushBuffer() throws IOException { } public int getBufferSize() { return 0; } public String getCharacterEncoding() { return null; } public Locale getLocale() { return null; } public ServletOutputStream getOutputStream() throws IOException { return null; } public PrintWriter getWriter() throws IOException { // autoflush is true, println() will flush, // but print() will not. writer = new PrintWriter(output, true); return writer; } public boolean isCommitted() { return false; } public void reset() { } public void resetBuffer() { } public void setBufferSize(int size) { } public void setContentLength(int length) { } public void setContentType(String type) { } public void setLocale(Locale locale) { } }
package ex02.pyrmont; import java.net.URL; import java.net.URLClassLoader; import java.net.URLStreamHandler; import java.io.File; import java.io.IOException; import javax.servlet.Servlet; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class ServletProcessor1 { public void process(Request request, Response response) { String uri = request.getUri(); String servletName = uri.substring(uri.lastIndexOf("/") + 1); URLClassLoader loader = null; try { URL[] urls = new URL[1]; URLStreamHandler streamHandler = null; File classPath = new File(Constants.WEB_ROOT); String repository = (new URL("file", null, classPath.getCanonicalPath() + File.separator)).toString() ; urls[0] = new URL(null, repository, streamHandler); loader = new URLClassLoader(urls); } catch (IOException e) { System.out.println(e.toString() ); } Class myClass = null; try { myClass = loader.loadClass(servletName); } catch (ClassNotFoundException e) { System.out.println(e.toString()); } Servlet servlet = null; try { servlet = (Servlet) myClass.newInstance(); servlet.service((ServletRequest) request, (ServletResponse) response); } catch (Exception e) { System.out.println(e.toString()); } catch (Throwable e) { System.out.println(e.toString()); } } }
package ex02.pyrmont; import java.io.IOException; public class StaticResourceProcessor { public void process(Request request, Response response) { try { response.sendStaticResource(); } catch (IOException e) { e.printStackTrace(); } } }