Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.wicket.request.http; import java.nio.charset.Charset; import java.util.List; import java.util.Locale; import javax.servlet.http.Cookie; import org.apache.wicket.request.IRequestParameters; import org.apache.wicket.request.Request; import org.apache.wicket.request.Url; import org.apache.wicket.util.string.StringValueConversionException; import org.apache.wicket.util.string.Strings; import org.apache.wicket.util.time.Time; /** * Base class for request that provides additional web-related information. * * @author Matej Knopp * @author Igor Vaynberg */ public abstract class WebRequest extends Request { /** marker for Ajax requests */ public static final String PARAM_AJAX = "wicket-ajax"; /** marker for Ajax requests */ public static final String HEADER_AJAX = "Wicket-Ajax"; /** marker for Ajax-relative url */ public static final String PARAM_AJAX_BASE_URL = "wicket-ajax-baseurl"; /** marker for Ajax-relative url */ public static final String HEADER_AJAX_BASE_URL = "Wicket-Ajax-BaseURL"; /** anti-cache query parameter added by Wicket.Ajax.Request at its URL */ public static final String PARAM_AJAX_REQUEST_ANTI_CACHE = "_"; /** {@code Origin} http header */ public static final String HEADER_ORIGIN = "Origin"; /** {@code Referer} http header */ public static final String HEADER_REFERER = "Referer"; /** * @return request cookies */ public abstract List<Cookie> getCookies(); /** * @param cookieName * @return cookie with specified name or <code>null</code> if the cookie does not exist */ public Cookie getCookie(final String cookieName) { for (Cookie cookie : getCookies()) { if (cookie.getName().equals(cookieName)) { return cookie; } } return null; } /** * Returns all the values of the specified request header. * * @param name * @return unmodifiable list of header values */ public abstract List<String> getHeaders(String name); /** * Returns the value of the specified request header as a <code>String</code> * * @param name * @return string value of request header */ public abstract String getHeader(String name); /** * Returns the value of the specified request header as a <code>long</code> value that * represents a <code>Date</code> object. Use this method with headers that contain dates, such * as <code>If-Modified-Since</code>. * * @param name * @return date value of request header or <code>null</code> if not found */ public abstract Time getDateHeader(String name); /** * Convenience method for retrieving If-Modified-Since header. * * @return date representing the header or <code>null</code> if not set */ public final Time getIfModifiedSinceHeader() { return getDateHeader("If-Modified-Since"); } /** * Returns whether this request is an Ajax request. This implementation checks for values of * {@value #PARAM_AJAX} url parameter or the {@value #HEADER_AJAX} header. Subclasses can use * other approaches. * * @return <code>true</code> if this request is an ajax request, <code>false</code> otherwise. */ public boolean isAjax() { try { return Strings.isTrue(getHeader(HEADER_AJAX)) || Strings.isTrue(getQueryParameters().getParameterValue(PARAM_AJAX).toString()); } catch (StringValueConversionException invalidValue) { return false; } } /** * Signals whether or not request processing should preserve the current client url - in other * words, handle this request without redirecting. By default, this method returns {@code false} * . * * For example, this method can be used to preserve the url that caused a 404 in the browser if * Wicket is also responsible for rendering the 404 page. If this method returns the default * value of {@code false} then Wicket will redirect to the bookmarkable url of the error page, * instead of preserving the url that caused the 404 in the browser. * * @return {@code true} if current client url should be preserved */ public boolean shouldPreserveClientUrl() { return false; } /** * Returns request with specified URL and same POST parameters as this request. * * @param url * Url instance * @return request with specified URL. */ @Override public WebRequest cloneWithUrl(final Url url) { return new WebRequest() { @Override public Url getUrl() { return url; } @Override public Url getOriginalUrl() { return WebRequest.this.getOriginalUrl(); } @Override public IRequestParameters getPostParameters() { return WebRequest.this.getPostParameters(); } @Override public List<Cookie> getCookies() { return WebRequest.this.getCookies(); } @Override public Time getDateHeader(final String name) { return WebRequest.this.getDateHeader(name); } @Override public Locale getLocale() { return WebRequest.this.getLocale(); } @Override public String getHeader(final String name) { return WebRequest.this.getHeader(name); } @Override public List<String> getHeaders(final String name) { return WebRequest.this.getHeaders(name); } @Override public Charset getCharset() { return WebRequest.this.getCharset(); } @Override public Url getClientUrl() { return WebRequest.this.getClientUrl(); } @Override public Object getContainerRequest() { return WebRequest.this.getContainerRequest(); } @Override public boolean shouldPreserveClientUrl() { return WebRequest.this.shouldPreserveClientUrl(); } }; } }