org.springframework.web.servlet.view.RedirectView Maven / Gradle / Ivy
/*
* Copyright 2002-2004 the original author or authors.
*
* Licensed 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.springframework.web.servlet.view;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* View that redirects to an internal or external URL,
* exposing all model attributes as HTTP query parameters.
*
* A URL for this view is supposed to be a HTTP redirect URL,
* i.e. suitable for HttpServletResponse's sendRedirect method.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see javax.servlet.http.HttpServletResponse#sendRedirect
*/
public class RedirectView extends AbstractUrlBasedView {
public static final String DEFAULT_ENCODING_SCHEME = "UTF-8";
private boolean contextRelative = false;
private boolean http10Compatible = true;
private String encodingScheme = DEFAULT_ENCODING_SCHEME;
/**
* Constructor for use as a bean.
*/
public RedirectView() {
}
/**
* Create a new RedirectView with the given URL.
* @param url the URL to redirect to
*/
public RedirectView(String url) {
setUrl(url);
}
/**
* Create a new RedirectView with the given URL.
* @param url the URL to redirect to
* @param contextRelative whether to interpret the given URL as
* relative to the current ServletContext
*/
public RedirectView(String url, boolean contextRelative) {
setUrl(url);
this.contextRelative = contextRelative;
}
/**
* Create a new RedirectView with the given URL.
* @param url the URL to redirect to
* @param contextRelative whether to interpret the given URL as
* relative to the current ServletContext
* @param http10Compatible whether to stay compatible with HTTP 1.0 clients
*/
public RedirectView(String url, boolean contextRelative, boolean http10Compatible) {
setUrl(url);
this.contextRelative = contextRelative;
this.http10Compatible = http10Compatible;
}
/**
* Set whether to interpret the given URL as relative to the current
* ServletContext, i.e. as relative to the web application root.
*
Default is false: The URL will be intepreted as absolute, i.e.
* taken as-is. If true, the context path will be prepended to the URL.
* @see javax.servlet.http.HttpServletRequest#getContextPath
*/
public void setContextRelative(boolean contextRelative) {
this.contextRelative = contextRelative;
}
/**
* Set whether to stay compatible with HTTP 1.0 clients.
*
In the default implementation, this will enforce HTTP status code
* 302 in any case, i.e. delegate to HttpServletResponse.sendRedirect.
* Turning this off will send HTTP status code 303, which is the correct
* code for HTTP 1.1 clients, but not understood by HTTP 1.0 clients.
*
Many HTTP 1.1 clients treat 302 just like 303, not making any
* difference. However, some clients depend on 303 when redirecting
* after a POST request; turn this flag off in such a scenario.
* @see javax.servlet.http.HttpServletResponse#sendRedirect
*/
public void setHttp10Compatible(boolean http10Compatible) {
this.http10Compatible = http10Compatible;
}
/**
* Set the encoding scheme for this view.
*/
public void setEncodingScheme(String encodingScheme) {
this.encodingScheme = encodingScheme;
}
/**
* Convert model to request parameters and redirect to the given URL.
* @see #appendQueryProperties
* @see #sendRedirect
*/
protected final void renderMergedOutputModel(
Map model, HttpServletRequest request, HttpServletResponse response) throws IOException {
// prepare target URL
StringBuffer targetUrl = new StringBuffer();
if (this.contextRelative) {
targetUrl.append(request.getContextPath());
}
targetUrl.append(getUrl());
appendQueryProperties(targetUrl, model, this.encodingScheme);
sendRedirect(request, response, targetUrl.toString(), this.http10Compatible);
}
/**
* Append query properties to the redirect URL.
* Stringifies, URL-encodes and formats model attributes as query properties.
* @param targetUrl the StringBuffer to append the properties to
* @param model Map that contains model attributes
* @param encodingScheme the encoding scheme to use
* @throws UnsupportedEncodingException if string encoding failed
* @see #queryProperties
*/
protected void appendQueryProperties(StringBuffer targetUrl, Map model, String encodingScheme)
throws UnsupportedEncodingException {
// if there are not already some parameters, we need a ?
boolean first = (getUrl().indexOf('?') < 0);
Iterator entries = queryProperties(model).entrySet().iterator();
while (entries.hasNext()) {
if (first) {
targetUrl.append('?');
first = false;
}
else {
targetUrl.append('&');
}
Map.Entry entry = (Map.Entry) entries.next();
String encodedKey = URLEncoder.encode(entry.getKey().toString());
String encodedValue = (entry.getValue() != null ? URLEncoder.encode(entry.getValue().toString()) : "");
targetUrl.append(new String(encodedKey.getBytes(encodingScheme), encodingScheme));
targetUrl.append("=");
targetUrl.append(new String(encodedValue.getBytes(encodingScheme), encodingScheme));
}
}
/**
* Determine name-value pairs for query strings, which will be stringified,
* URL-encoded and formatted by appendQueryProperties.
*
This implementation returns all model elements as-is.
* @see #appendQueryProperties
*/
protected Map queryProperties(Map model) {
return model;
}
/**
* Send a redirect back to the HTTP client
* @param request current HTTP request (allows for reacting to request method)
* @param response current HTTP response (for sending response headers)
* @param targetUrl the target URL to redirect to
* @param http10Compatible whether to stay compatible with HTTP 1.0 clients
* @throws IOException if thrown by response methods
*/
protected void sendRedirect(
HttpServletRequest request, HttpServletResponse response, String targetUrl, boolean http10Compatible)
throws IOException {
if (http10Compatible) {
// always send status code 302
response.sendRedirect(response.encodeRedirectURL(targetUrl));
}
else {
// correct HTTP status code is 303, in particular for POST requests
response.setStatus(303);
response.setHeader("Location", response.encodeRedirectURL(targetUrl));
}
}
}