org.apache.tuscany.sca.common.http.HTTPCacheContext Maven / Gradle / Ivy
/*
* 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.tuscany.sca.common.http;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.http.HttpServletRequest;
/**
* A class to store cache settings for Atom and HTTP requests and responses.
*
* Predicates are statements that work in conjunction with
* ETags and LastModified dates to determine if a precondition
* or postcondition is satisfied.
* See HTTP specification for how predicates wrk:
* http://tools.ietf.org/html/rfc2616
* Example predicates in HTTP include If-Match, If-None-Match,
* If-Modified-Since, If-Unmodified-Since, If-Range.
*
* @version $Rev: 1056788 $ $Date: 2011-01-08 22:18:48 +0200 (Sat, 08 Jan 2011) $
*/
public class HTTPCacheContext {
public static final SimpleDateFormat RFC822DateFormat = new SimpleDateFormat( "EEE, dd MMM yyyy HH:mm:ss Z" ); // RFC 822 date time
public boolean enabled;
public String eTag;
public String lastModified;
public Date lastModifiedDate;
public boolean ifModifiedSince;
public boolean ifUnmodifiedSince;
public boolean ifMatch;
public boolean ifNoneMatch;
public boolean ifRange;
/**
* Enabled is true whenever ETag, LastModified, or predicate is set.
* @return the enabled
*/
public boolean isEnabled() {
return enabled;
}
/**
* @param enabled the enabled to set
*/
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
/**
* An ETag is a unique ID for an item. It changes when
* a field in the item or the update date changes.
* See HTTP specification for how ETags work:
* http://tools.ietf.org/html/rfc2616
* @return the eTag
*/
public String getETag() {
return eTag;
}
/**
* @param tag the eTag to set
*/
public void setETag(String tag) {
eTag = tag;
enabled = true;
}
/**
* The LastModified date is the time the item was last
* changed. See HTTP specification for how ETags work:
* http://tools.ietf.org/html/rfc2616
* @return the lastModified
*/
public String getLastModified() {
return lastModified;
}
/**
* The LastModified date is the time the item was last
* changed. See HTTP specification for how ETags work:
* http://tools.ietf.org/html/rfc2616
* @return the lastModified
*/
public Date getLastModifiedAsDate() {
return lastModifiedDate;
}
/**
* @param lastModified the lastModified to set
*/
public void setLastModified(String lastModified) throws java.text.ParseException {
this.lastModified = lastModified;
// Catch date formatting on input to help debugging.
lastModifiedDate = RFC822DateFormat.parse( lastModified );
enabled = true;
}
/**
* @param lastModified the lastModified to set
*/
public void setLastModified(Date updated) {
this.lastModified = RFC822DateFormat.format( updated );
lastModifiedDate = updated;
enabled = true;
}
/**
* @return the ifModifedSince
*/
public boolean isIfModifiedSince() {
return ifModifiedSince;
}
/**
* @param ifModifedSince the ifModifedSince to set
*/
public void setIfModifiedSince(boolean ifModifiedSince) {
this.ifModifiedSince = ifModifiedSince;
if ( ifModifiedSince ) {
enabled = true;
}
}
/**
* @return the ifUnModifiedSince
*/
public boolean isIfUnmodifiedSince() {
return ifUnmodifiedSince;
}
/**
* @param ifUnModifiedSince the ifUnModifiedSince to set
*/
public void setIfUnmodifiedSince(boolean ifUnmodifiedSince) {
this.ifUnmodifiedSince = ifUnmodifiedSince;
if ( ifUnmodifiedSince ) {
enabled = true;
}
}
/**
* @return the ifMatch
*/
public boolean isIfMatch() {
return ifMatch;
}
/**
* @param ifMatch the ifMatch to set
*/
public void setIfMatch(boolean ifMatch) {
this.ifMatch = ifMatch;
if ( ifMatch ) {
enabled = true;
}
}
/**
* @return the ifNoneMatch
*/
public boolean isIfNoneMatch() {
return ifNoneMatch;
}
/**
* @param ifNoneMatch the ifNoneMatch to set
*/
public void setIfNoneMatch(boolean ifNoneMatch) {
this.ifNoneMatch = ifNoneMatch;
if ( ifNoneMatch ) {
enabled = true;
}
}
/**
* @return the ifRange
*/
public boolean isIfRange() {
return ifRange;
}
/**
* @param ifRange the ifRange to set
*/
public void setIfRange(boolean ifRange) {
this.ifRange = ifRange;
if ( ifRange ) {
enabled = true;
}
}
/**
* Gets the cache context information (ETag, LastModified, predicates) from the Http request.
* @param request
* @return
*/
public static HTTPCacheContext createCacheContextFromRequest( HttpServletRequest request ) throws java.text.ParseException {
HTTPCacheContext context = new HTTPCacheContext();
String eTag = request.getHeader( "If-Match" );
if ( eTag != null ) {
context.setETag( eTag );
context.setIfMatch( true );
}
eTag = request.getHeader( "If-None-Match" );
if ( eTag != null ) {
context.setETag( eTag );
context.setIfNoneMatch( true );
}
String lastModifiedString = request.getHeader( "If-Modified-Since" );
if ( lastModifiedString != null ) {
context.setLastModified( lastModifiedString );
context.setIfModifiedSince( true );
}
lastModifiedString = request.getHeader( "If-Unmodified-Since" );
if ( lastModifiedString != null ) {
context.setLastModified( lastModifiedString );
context.setIfUnmodifiedSince( true );
}
lastModifiedString = request.getHeader( "If-Range" );
if ( lastModifiedString != null ) {
context.setLastModified( lastModifiedString );
context.setIfRange( true );
}
return context;
}
public String toString() {
final String PREDPREFIX = ", predicates=";
StringBuffer sb = new StringBuffer(PREDPREFIX);
if ( ifMatch || ifNoneMatch || ifModifiedSince || ifUnmodifiedSince || ifRange ) {
if ( ifMatch ) {
if ( sb.length() > PREDPREFIX.length() ) sb.append( ", ");
sb.append("If-Match");
}
if ( ifNoneMatch ) {
if ( sb.length() > PREDPREFIX.length() ) sb.append( ", ");
sb.append("If-None-Match");
}
if ( ifModifiedSince ) {
if ( sb.length() > PREDPREFIX.length() ) sb.append( ", ");
sb.append("If-Modified-Since");
}
if ( ifUnmodifiedSince ) {
if ( sb.length() > PREDPREFIX.length() ) sb.append( ", ");
sb.append("If-UnModified-Since");
}
if ( ifRange ) {
if ( sb.length() > PREDPREFIX.length() ) sb.append( ", ");
sb.append("If-Range");
}
} else {
sb.append("null");
}
return "eTag=" + eTag + ", lastModified=" + lastModified
+ sb.toString();
}
}