tomcat內(nèi)部工作原理講解-資料下載頁
2025-06-25 23:12本頁面
【正文】 ServletRequest對象和一個ServletResponse對象并把它們傳遞給正在服務(wù)的servlet的service方法。 。就本身而言，它必須實現(xiàn) 。這個類必須提供這個接口所有方法的實現(xiàn)。不過，我們想要讓它非常簡單并且僅僅提供實現(xiàn)其 中一些方法，我們在以下各章中再實現(xiàn)全部的方法。要編譯Request類，你需要把這些方法的實現(xiàn)留空。假如你看過Listing ，你將會看到那些需要返回一個對象的方法返回了nullListing : Request類package 。import 。import 。import 。import 。import 。import 。import 。import 。import 。import 。public class Request implements ServletRequest {private InputStream input。private String uri。public Request(InputStream input){ = input。}public String getUri() {return uri。}private String parseUri(String requestString) {int index1, index2。index1 = (39。 39。)。if (index1 != 1) {index2 = (39。 39。, index1 + 1)。if (index2 index1)return (index1 + 1, index2)。}return null。}public void parse() {// Read a set of characters from the socketStringBuffer request = new StringBuffer(2048)。int i。byte[] buffer = new byte[2048]。try {i = (buffer)。 }catch (IOException e) {()。i = 1。}for (int j=0。 ji。 j++) {((char) buffer(j))。}(())。uri = parseUri(())。}/* implementation of 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 { }} 另外，Request類仍然有在第1章中討論的parse和getUri方法。Response類 在Listing 。就本身而言，這個類必 須提供接口里邊的所有方法的實現(xiàn)。類似于Request類，我們把除了getWriter之外的所有方法的實現(xiàn)留空。Listing : Response類 package 。import 。import 。import 。import 。import 。import 。import 。import 。import 。public class Response implements ServletResponse {private static final int BUFFER_SIZE = 1024。Request request。OutputStream output。PrintWriter writer。public Response(OutputStream output) { = output。}public void setRequest(Request request) { = request。}/* This method is used to serve static pages */public void sendStaticResource() throws IOException {byte[] bytes = new byte[BUFFER_SIZE]。FileInputstream fis = null。try {/* has been replaced by */File file = new File(, ())。fis = new FileInputstream(file)。/*HTTP Response = StatusLine*(( generalheader | responseheader | entityheader ) CRLF)CRLF[ messagebody ]StatusLine = HTTPVersion SP StatusCode SP ReasonPhrase CRLF*/int ch = (bytes, 0, BUFFER_SIZE)。while (ch!=1) {(bytes, 0, ch)。ch = (bytes, 0, BUFFER_SIZE)。}}catch (FileNotFoundException e) {String errorMessage = HTTP/ 404 File Not Found\r\n +ContentType: text/html\r\n +ContentLength: 23\r\n +\r\n +h1File Not Found/h1。(())。}finally {16
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