/*
* Copyright (c) 2010. All rights reserved.
*/
package ro.isdc.wro.config;
import static org.apache.commons.lang3.Validate.notNull;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.Callable;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import ro.isdc.wro.WroRuntimeException;
import ro.isdc.wro.config.jmx.WroConfiguration;
import ro.isdc.wro.config.support.ContextPropagatingCallable;
import ro.isdc.wro.http.WroFilter;
/**
* Holds the properties related to a request cycle.
*
* @author Alex Objelean
*/
public class Context
implements ReadOnlyContext {
/**
* Maps correlationId with a Context.
*/
private static final Map<String, Context> CONTEXT_MAP = Collections.synchronizedMap(new HashMap<String, Context>());
/**
* Holds a correlationId, created in {@link WroFilter}. A correlationId will be associated with a {@link Context}
* object.
*/
private static ThreadLocal<String> CORRELATION_ID = new ThreadLocal<String>();
private WroConfiguration config;
/**
* Request.
*/
private transient HttpServletRequest request;
/**
* Response.
*/
private transient HttpServletResponse response;
/**
* ServletContext.
*/
private transient ServletContext servletContext;
/**
* FilterConfig.
*/
private transient FilterConfig filterConfig;
/**
* The path to the folder, relative to the root, used to compute rewritten image url.
*/
private String aggregatedFolderPath;
/**
* @return {@link WroConfiguration} singleton instance.
*/
public WroConfiguration getConfig() {
return config;
}
/**
* DO NOT CALL THIS METHOD UNLESS YOU ARE SURE WHAT YOU ARE DOING.
* <p/>
* sets the {@link WroConfiguration} singleton instance.
*/
public void setConfig(final WroConfiguration config) {
notNull(config);
this.config = config;
}
/**
* A context useful for running in web context (inside a servlet container).
*/
public static Context webContext(final HttpServletRequest request, final HttpServletResponse response,
final FilterConfig filterConfig) {
return new Context(request, response, filterConfig);
}
/**
* A context useful for running in non web context (standalone applications).
*/
public static Context standaloneContext() {
return new Context();
}
/**
* @return {@link Context} associated with CURRENT request cycle.
*/
public static Context get() {
validateContext();
final String correlationId = CORRELATION_ID.get();
return CONTEXT_MAP.get(correlationId);
}
/**
* @return true if the call is done during wro4j request cycle. In other words, if the context is set.
*/
public static boolean isContextSet() {
return CORRELATION_ID.get() != null && CONTEXT_MAP.get(CORRELATION_ID.get()) != null;
}
/**
* Checks if the {@link Context} is accessible from current request cycle.
*/
private static void validateContext() {
if (!isContextSet()) {
throw new WroRuntimeException("No context associated with CURRENT request cycle!");
}
}
/**
* Set a context with default configuration to current thread.
*/
public static void set(final Context context) {
set(context, new WroConfiguration());
}
/**
* Associate a context with the CURRENT request cycle.
*
* @param context {@link Context} to set.
*/
public static void set(final Context context, final WroConfiguration config) {
notNull(context);
notNull(config);
context.setConfig(config);
final String correlationId = generateCorrelationId();
CORRELATION_ID.set(correlationId);
CONTEXT_MAP.put(correlationId, context);
}
/**
* @return a string representation of an unique id used to store Context in a map.
*/
private static String generateCorrelationId() {
return UUID.randomUUID().toString();
}
/**
* Remove context from the local thread.
*/
public static void unset() {
final String correlationId = CORRELATION_ID.get();
if (correlationId != null) {
CONTEXT_MAP.remove(correlationId);
}
CORRELATION_ID.remove();
}
/**
* Perform context clean-up.
*/
public static void destroy() {
unset();
//remove all context objects stored in map
CONTEXT_MAP.clear();
}
/**
* Set the correlationId to the current thread.
*/
public static void setCorrelationId(final String correlationId) {
notNull(correlationId);
CORRELATION_ID.set(correlationId);
}
/**
* Remove the correlationId from the current thread. This operation will not remove the {@link Context} associated
* with the correlationId. In order to remove context, call {@link Context#unset()}.
* <p/>
* Unsetting correlationId is useful when you create child threads which needs to access the correlationId from the
* parent thread. This simulates the {@link InheritableThreadLocal} functionality.
*/
public static void unsetCorrelationId() {
CORRELATION_ID.remove();
}
/**
* @return the correlationId associated with this thread.
*/
public static String getCorrelationId() {
validateContext();
return CORRELATION_ID.get();
}
/**
* Decorates a callable with {@link ContextPropagatingCallable} making it possible to access the {@link Context} from
* within the decorated callable.
*
* @param callable
* the {@link Callable} to decorate.
* @return the decorated callable.
*/
public static <T> Callable<T> decorate(final Callable<T> callable) {
return new ContextPropagatingCallable<T>(callable);
}
/**
* @return number of {@link Context} objects which were created but not yet destroyed. This is useful to detect leaks
* (mostly for unit testing).
*/
public static int countActive() {
return CONTEXT_MAP.size();
}
/**
* Private constructor. Used to build {@link StandAloneContext}.
*/
private Context() {}
/**
* Constructor.
*/
private Context(final HttpServletRequest request, final HttpServletResponse response, final FilterConfig filterConfig) {
notNull(request);
notNull(response);
this.request = request;
this.response = response;
this.servletContext = filterConfig != null ? filterConfig.getServletContext() : null;
this.filterConfig = filterConfig;
}
/**
* @return the request
*/
public HttpServletRequest getRequest() {
return this.request;
}
/**
* @return the response
*/
public HttpServletResponse getResponse() {
return this.response;
}
/**
* @return the servletContext
*/
public ServletContext getServletContext() {
return this.servletContext;
}
/**
* @return the filterConfig
*/
public FilterConfig getFilterConfig() {
return this.filterConfig;
}
/**
* {@inheritDoc}
*/
public String getAggregatedFolderPath() {
return this.aggregatedFolderPath;
}
/**
* @param aggregatedFolderPath the aggregatedFolderPath to set
*/
public void setAggregatedFolderPath(final String aggregatedFolderPath) {
this.aggregatedFolderPath = aggregatedFolderPath;
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this, ToStringStyle.MULTI_LINE_STYLE);
}
}