/*
* $Id$
*
* 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.rest;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.DefaultActionInvocation;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Result;
import com.opensymphony.xwork2.ValidationAware;
import com.opensymphony.xwork2.config.ConfigurationException;
import com.opensymphony.xwork2.config.entities.ActionConfig;
import com.opensymphony.xwork2.config.entities.ResultConfig;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import com.opensymphony.xwork2.util.profiling.UtilTimerStack;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.HttpHeaderResult;
import org.apache.struts2.rest.handler.ContentTypeHandler;
import org.apache.struts2.rest.handler.HtmlHandler;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;
/**
* Extends the usual {@link ActionInvocation} to add support for processing the object returned
* from the action execution. This allows us to support methods that return {@link HttpHeaders}
* as well as apply content type-specific operations to the result.
*/
public class RestActionInvocation extends DefaultActionInvocation {
private static final long serialVersionUID = 3485701178946428716L;
private static final Logger LOG = LoggerFactory.getLogger(RestActionInvocation.class);
private ContentTypeHandlerManager handlerSelector;
private boolean logger;
private String defaultErrorResultName;
private boolean restrictToGet = true;
protected HttpHeaders httpHeaders;
protected Object target;
protected boolean isFirstInterceptor = true;
protected boolean hasErrors;
protected RestActionInvocation(final Map<String, Object> extraContext, boolean pushAction) {
super(extraContext, pushAction);
}
@Inject("struts.rest.logger")
public void setLogger(String value) {
logger = Boolean.valueOf(value);
}
@Inject("struts.rest.defaultErrorResultName")
public void setDefaultErrorResultName(String value) {
defaultErrorResultName = value;
}
/**
* If set to true (by default) blocks returning content from any other methods than GET,
* if set to false, the content can be returned for any kind of method
*
* @param value true or false
*/
@Inject(value = "struts.rest.content.restrictToGET", required = false)
public void setRestrictToGet(String value) {
restrictToGet = "true".equalsIgnoreCase(value);
}
@Inject
public void setMimeTypeHandlerSelector(ContentTypeHandlerManager sel) {
this.handlerSelector = sel;
}
/**
* Save the result to be used later.
* @param actionConfig current ActionConfig
* @param methodResult the result of the action.
* @return the result code to process.
*
* @throws ConfigurationException If it is an incorrect result.
*/
@Override
protected String saveResult(ActionConfig actionConfig, Object methodResult) {
if (methodResult instanceof Result) {
explicitResult = (Result) methodResult;
// Wire the result automatically
container.inject(explicitResult);
} else if (methodResult instanceof HttpHeaders) {
httpHeaders = (HttpHeaders) methodResult;
resultCode = httpHeaders.getResultCode();
} else if (methodResult instanceof String) {
resultCode = (String) methodResult;
} else if (methodResult != null) {
throw new ConfigurationException("The result type " + methodResult.getClass()
+ " is not allowed. Use the type String, HttpHeaders or Result.");
}
return resultCode;
}
@Override
public String invoke() throws Exception {
long startTime = 0;
boolean executeResult = false;
if (isFirstInterceptor) {
startTime = System.currentTimeMillis();
executeResult = true;
isFirstInterceptor = false;
}
// Normal invoke without execute the result
proxy.setExecuteResult(false);
resultCode = super.invoke();
// Execute the result when the last interceptor has finished
if (executeResult) {
long middleTime = System.currentTimeMillis();
try {
processResult();
} catch (ConfigurationException e) {
throw e;
} catch (Exception e) {
// Error proccesing the result
LOG.error("Exception processing the result.", e);
if (!ServletActionContext.getResponse().isCommitted()) {
ServletActionContext.getResponse()
.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
stack.set("exception", e);
result = null;
resultCode = null;
processResult();
}
}
// Log execution + result time
logger(startTime, middleTime);
}
return resultCode;
}
protected void processResult() throws Exception {
String timerKey = "processResult: " + getResultCode();
try {
UtilTimerStack.push(timerKey);
HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();
// Select the target
selectTarget();
// Get the httpHeaders
if (httpHeaders == null) {
httpHeaders = new DefaultHttpHeaders(resultCode);
}
// Apply headers
if (!hasErrors) {
httpHeaders.apply(request, response, target);
} else {
disableCatching(response);
}
// Don't return content on a not modified
if (httpHeaders.getStatus() != HttpServletResponse.SC_NOT_MODIFIED ) {
executeResult();
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Result not processed because the status code is not modified.");
}
}
} finally {
UtilTimerStack.pop(timerKey);
}
}
/**
* Execute the current result. If it is an error and no result is selected load
* the default error result (default-error).
*/
private void executeResult() throws Exception {
// Get handler by representation
ContentTypeHandler handler = handlerSelector.getHandlerForResponse(
ServletActionContext.getRequest(), ServletActionContext.getResponse());
// get the result
this.result = createResult();
if (this.result instanceof HttpHeaderResult) {
// execute the result to apply headers and status in every representations
this.result.execute(this);
updateStatusFromResult();
}
if (handler != null && !(handler instanceof HtmlHandler)) {
// Specific representation (json, xml...)
resultCode = handlerSelector.handleResult(
this.getProxy().getConfig(), httpHeaders, target);
} else {
// Normal struts execution (html o other struts result)
findResult();
if (result != null) {
this.result.execute(this);
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("No result returned for action " + getAction().getClass().getName()
+ " at " + proxy.getConfig().getLocation());
}
}
}
}
/**
* Get the status code from HttpHeaderResult and it is saved in the HttpHeaders object.
*/
protected void updateStatusFromResult() {
if (result instanceof HttpHeaderResult) {
int status = ((HttpHeaderResult) result).getStatus();
if (status != -1) {
httpHeaders.setStatus(status);
}
}
}
/**
* Find the most appropriate result:
* - Find by result code.
* - If it is an error, find the default error result.
*
* @throws ConfigurationException If not result can be found
*/
private void findResult() throws Exception {
boolean isHttpHeaderResult = false;
if (result != null && result instanceof HttpHeaderResult) {
result = null;
isHttpHeaderResult = true;
}
if (result == null && resultCode != null && !Action.NONE.equals(resultCode)
&& unknownHandlerManager.hasUnknownHandlers()) {
// Find result by resultCode
this.result = unknownHandlerManager.handleUnknownResult(
invocationContext, proxy.getActionName(), proxy.getConfig(), resultCode);
}
if (result == null && hasErrors && defaultErrorResultName != null) {
// Get default error result
ResultConfig resultConfig = this.proxy.getConfig().getResults().get(defaultErrorResultName);
if (resultConfig != null) {
this.result = objectFactory.buildResult(resultConfig, invocationContext.getContextMap());
if (LOG.isDebugEnabled()) {
LOG.debug("Found default error result.");
}
}
}
if (result == null && resultCode != null &&
!Action.NONE.equals(resultCode) && !isHttpHeaderResult) {
throw new ConfigurationException("No result defined for action "
+ getAction().getClass().getName()
+ " and result " + getResultCode(), proxy.getConfig());
}
}
@SuppressWarnings("unchecked")
protected void selectTarget() {
// Select target (content to return)
Throwable e = (Throwable)stack.findValue("exception");
if (e != null) {
// Exception
target = e;
hasErrors = true;
} else if (action instanceof ValidationAware && ((ValidationAware)action).hasErrors()) {
// Error messages
ValidationAware validationAwareAction = ((ValidationAware)action);
Map errors = new HashMap();
if (validationAwareAction.getActionErrors().size() > 0) {
errors.put("actionErrors", validationAwareAction.getActionErrors());
}
if (validationAwareAction.getFieldErrors().size() > 0) {
errors.put("fieldErrors", validationAwareAction.getFieldErrors());
}
target = errors;
hasErrors = true;
} else if (action instanceof ModelDriven) {
// Model
target = ((ModelDriven)action).getModel();
} else {
target = action;
}
if (shouldRestrictToGET()) {
target = null;
}
}
// don't return any content for PUT, DELETE, and POST where there are no errors
// or backward compatible restrictToGET flag is set to true
private boolean shouldRestrictToGET() {
return !hasErrors
&& !"get".equalsIgnoreCase(ServletActionContext.getRequest().getMethod())
&& restrictToGet;
}
private void disableCatching(HttpServletResponse response) {
// No cache
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Last-Modified", 0);
response.setHeader("ETag", "-1");
}
private void logger(long startTime, long middleTime) {
if (logger && LOG.isInfoEnabled()) {
long endTime = System.currentTimeMillis();
long executionTime = middleTime - startTime;
long processResult = endTime - middleTime;
long total = endTime - startTime;
String message = "Executed action [/";
String namespace = getProxy().getNamespace();
if ((namespace != null) && (namespace.trim().length() > 1)) {
message += namespace + "/";
}
message += getProxy().getActionName() + "!" + getProxy().getMethod();
String extension = handlerSelector.findExtension(
ServletActionContext.getRequest().getRequestURI());
if (extension != null) {
message += "!" + extension;
}
if (httpHeaders != null) {
message += "!" + httpHeaders.getStatus();
}
message += "] took " + total + " ms (execution: " + executionTime
+ " ms, result: " + processResult + " ms)";
LOG.info(message);
}
}
}