PostbackResult.java
/*
* 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.struts2.result;
import org.apache.struts2.ActionContext;
import org.apache.struts2.ActionInvocation;
import org.apache.struts2.inject.Inject;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.struts2.dispatcher.mapper.ActionMapper;
import org.apache.struts2.dispatcher.mapper.ActionMapping;
import java.io.PrintWriter;
import java.io.Serial;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.Map;
/**
* <!-- START SNIPPET: description -->
* <p>
* A result that renders the current request parameters as a form which
* immediately submits a <a href="http://en.wikipedia.org/wiki/Postback">postback</a>
* to the specified destination.
* </p>
* <!-- END SNIPPET: description -->
* <p>
* <b>Parameters:</b>
* </p>
* <!-- START SNIPPET: params -->
* <ul>
* <li>location - http location to post the form</li>
* <li>prependServletContext (true|false) - when location is relative, controls if to add Servlet Context, default "true"</li>
* <li>actionName - action name to post the form (resolved as an expression)</li>
* <li>namespace - action's namespace to use (resolved as an expression)</li>
* <li>method - actions' method to use (resolved as an expression)</li>
* <li>cache (true|false) - when set to true adds cache control headers, default "true"</li>
* <li>parse (true|false) - when set to true actionName, namespace and method are parsed, default "true"</li>
* </ul>
* <!-- END SNIPPET: params -->
* <p>
* <b>Examples:</b>
* </p>
* <pre>
* <!-- START SNIPPET: example -->
* <action name="registerThirdParty" >
* <result type="postback">https://www.example.com/register</result>
* </action>
*
* <action name="registerThirdParty" >
* <result type="postback">
* <param name="namespace">/secure</param>
* <param name="actionName">register2</param>
* </result>
* </action>
* <!-- END SNIPPET: example -->
* </pre>
*/
public class PostbackResult extends StrutsResultSupport {
@Serial
private static final long serialVersionUID = -2283504349296877429L;
private String actionName;
private String namespace;
private String method;
private boolean prependServletContext = true;
private boolean cache = true;
protected ActionMapper actionMapper;
@Override
protected void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
ActionContext ctx = invocation.getInvocationContext();
HttpServletRequest request = ctx.getServletRequest();
HttpServletResponse response = ctx.getServletResponse();
// Cache?
if (!cache) {
response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1
response.setHeader("Pragma", "no-cache"); // HTTP 1.0
response.setDateHeader("Expires", 0); // Proxies
}
//set contenttype @see ww-4564
response.setContentType("text/html");
// Render
PrintWriter pw = new PrintWriter(response.getOutputStream());
pw.write("<!DOCTYPE html><html><body><form action=\"" + finalLocation + "\" method=\"POST\">");
writeFormElements(request, pw);
writePrologueScript(pw);
pw.write("</html>");
pw.flush();
}
@Override
public void execute(ActionInvocation invocation) throws Exception {
if (invocation == null) {
throw new IllegalArgumentException("Invocation cannot be null!");
}
String postbackUri = makePostbackUri(invocation);
setLocation(postbackUri);
super.execute(invocation);
}
/**
* Determines if the specified form input element should be included.
*
* @param name the input element name
* @param values the input element values
* @return {@code true} if included; otherwise {@code false}
*/
protected boolean isElementIncluded(String name, String[] values) {
return !name.startsWith("action:");
}
protected String makePostbackUri(ActionInvocation invocation) {
ActionContext ctx = invocation.getInvocationContext();
HttpServletRequest request = ctx.getServletRequest();
String postbackUri;
if (actionName != null) {
actionName = conditionalParse(actionName, invocation);
parseLocation = false;
if (namespace == null) {
namespace = invocation.getProxy().getNamespace();
} else {
namespace = conditionalParse(namespace, invocation);
}
if (method == null) {
method = "";
} else {
method = conditionalParse(method, invocation);
}
postbackUri = request.getContextPath() + actionMapper.getUriFromActionMapping(new ActionMapping(actionName, namespace, method, null));
} else {
String location = getLocation();
// Do not prepend if the URL is a FQN
if (!location.matches("^([a-zA-Z]+:)?//.*")) {
// If the URL is relative to the servlet context, prepend the servlet context path
if (prependServletContext && request.getContextPath() != null && !request.getContextPath().isEmpty()) {
location = request.getContextPath() + location;
}
}
postbackUri = location;
}
return postbackUri;
}
@Inject
public final void setActionMapper(ActionMapper mapper) {
this.actionMapper = mapper;
}
/**
* Sets the name of the destination action.
*
* @param actionName the action name
*/
public final void setActionName(String actionName) {
this.actionName = actionName;
}
/**
* Stores the option to cache the rendered intermediate page. The default
* is {@code true}.
*
* @param cache enable/disable cache
*/
public final void setCache(boolean cache) {
this.cache = cache;
}
/**
* Sets the method of the destination action.
*
* @param method the method
*/
public final void setMethod(String method) {
this.method = method;
}
/**
* Sets the namespace of the destination action.
*
* @param namespace the namespace
*/
public final void setNamespace(String namespace) {
this.namespace = namespace;
}
public final void setPrependServletContext(boolean prependServletContext) {
this.prependServletContext = prependServletContext;
}
protected void writeFormElement(PrintWriter pw, String name, String[] values) throws UnsupportedEncodingException {
for (String value : values) {
String encName = URLEncoder.encode(name, StandardCharsets.UTF_8);
String encValue = URLEncoder.encode(value, StandardCharsets.UTF_8);
pw.write("<input type=\"hidden\" name=\"" + encName + "\" value=\"" + encValue + "\"/>");
}
}
private void writeFormElements(HttpServletRequest request, PrintWriter pw) throws UnsupportedEncodingException {
Map<String, String[]> params = request.getParameterMap();
for (Map.Entry<String, String[]> entry : params.entrySet()) {
String name = entry.getKey();
String[] values = entry.getValue();
if (isElementIncluded(name, values)) {
writeFormElement(pw, name, values);
}
}
}
/**
* Outputs the script after the form has been emitted. The default script
* is to submit the form using a JavaScript time out that immediately expires.
*
* @param pw the print writer
*/
protected void writePrologueScript(PrintWriter pw) {
pw.write("<script>");
pw.write("setTimeout(function(){document.forms[0].submit();},0);");
pw.write("</script>");
}
}