HTTPCLIENT-975: committed patch to support stale-if-error from

RFC5861, with thanks to Mohammed Azeem Uddin
(mohammedazeem_uddin at comcast dot com).


git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1049179 13f79535-47bb-0310-9956-ffa450edef68

httpclient-cache/src/main/java/org/apache/http/impl/client/cache/CacheValidityPolicy.java

@@ -30,6 +30,7 @@ import java.util.Date;
 
 import org.apache.http.Header;
 import org.apache.http.HeaderElement;
+import org.apache.http.HttpRequest;
 import org.apache.http.annotation.Immutable;
 import org.apache.http.client.cache.HeaderConstants;
 import org.apache.http.client.cache.HttpCacheEntry;
@@ -119,6 +120,35 @@ class CacheValidityPolicy {
         return hasCacheControlDirective(entry, "proxy-revalidate");
     }
     
+    public boolean mayReturnStaleIfError(HttpRequest request,
+            HttpCacheEntry entry, Date now) {
+        long stalenessSecs = getStalenessSecs(entry, now);
+        return mayReturnStaleIfError(request.getHeaders("Cache-Control"),
+                                     stalenessSecs)
+                || mayReturnStaleIfError(entry.getHeaders("Cache-Control"),
+                                         stalenessSecs);
+    }
+    
+    private boolean mayReturnStaleIfError(Header[] headers, long stalenessSecs) {
+        boolean result = false;
+        for(Header h : headers) {
+            for(HeaderElement elt : h.getElements()) {
+                if ("stale-if-error".equals(elt.getName())) {
+                    try {
+                        int staleIfErrorSecs = Integer.parseInt(elt.getValue());
+                        if (stalenessSecs <= staleIfErrorSecs) {
+                            result = true;
+                            break;
+                        }
+                    } catch (NumberFormatException nfe) {
+                        // skip malformed directive
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
     protected Date getDateValue(final HttpCacheEntry entry) {
         Header dateHdr = entry.getFirstHeader(HTTP.DATE_HEADER);
         if (dateHdr == null)

httpclient-cache/src/main/java/org/apache/http/impl/client/cache/CachingHttpClient.java

@@ -692,10 +692,24 @@ public class CachingHttpClient implements HttpClient {
             return responseGenerator.generateResponse(updatedEntry);
         }
         
+        if (staleIfErrorAppliesTo(statusCode)
+            && validityPolicy.mayReturnStaleIfError(request, cacheEntry, responseDate)) {
+            final HttpResponse cachedResponse = responseGenerator.generateResponse(cacheEntry);
+            cachedResponse.addHeader(HeaderConstants.WARNING, "110 localhost \"Response is stale\"");
+            return cachedResponse; 
+        }
+
         return handleBackendResponse(target, conditionalRequest, requestDate, responseDate,
                                      backendResponse);
     }
 
+	private boolean staleIfErrorAppliesTo(int statusCode) {
+	    return statusCode == HttpStatus.SC_INTERNAL_SERVER_ERROR  
+        		|| statusCode == HttpStatus.SC_BAD_GATEWAY  
+        		|| statusCode == HttpStatus.SC_SERVICE_UNAVAILABLE  
+        		|| statusCode == HttpStatus.SC_GATEWAY_TIMEOUT;
+    }
+
     HttpResponse handleBackendResponse(
             HttpHost target,
             HttpRequest request,

httpclient-cache/src/test/java/org/apache/http/impl/client/cache/HttpTestUtils.java

@@ -31,6 +31,7 @@ import java.util.Date;
 import java.util.Map;
 import java.util.Random;
 import org.apache.http.Header;
+import org.apache.http.HeaderElement;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpMessage;
 import org.apache.http.HttpRequest;
@@ -43,8 +44,10 @@ import org.apache.http.client.cache.HttpCacheEntry;
 import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.impl.cookie.DateUtils;
 import org.apache.http.message.BasicHeader;
+import org.apache.http.message.BasicHttpRequest;
 import org.apache.http.message.BasicHttpResponse;
 import org.apache.http.message.BasicStatusLine;
+import org.junit.Assert;
 
 public class HttpTestUtils {
 
@@ -297,4 +300,35 @@ public class HttpTestUtils {
         out.setEntity(makeBody(128));
         return out;
     }
+
+    public static final HttpResponse make200Response(Date date, String cacheControl) {
+        HttpResponse response = HttpTestUtils.make200Response();
+        response.setHeader("Date", DateUtils.formatDate(date));
+        response.setHeader("Cache-Control",cacheControl);
+        response.setHeader("Etag","\"etag\"");
+        return response;
+    }
+
+    public static final void assert110WarningFound(HttpResponse response) {
+        boolean found110Warning = false;
+        for(Header h : response.getHeaders("Warning")) {
+            for(HeaderElement elt : h.getElements()) {
+                String[] parts = elt.getName().split("\\s");
+                if ("110".equals(parts[0])) {
+                    found110Warning = true;
+                    break;
+                }
+            }
+        }
+        Assert.assertTrue(found110Warning);
+    }
+
+    public static HttpRequest makeDefaultRequest() {
+        return new BasicHttpRequest("GET","/",HttpVersion.HTTP_1_1);
+    }
+
+    public static HttpResponse make500Response() {
+        return new BasicHttpResponse(HttpVersion.HTTP_1_1,
+                HttpStatus.SC_INTERNAL_SERVER_ERROR, "Internal Server Error");
+    }
 }

httpclient-cache/src/test/java/org/apache/http/impl/client/cache/TestCacheValidityPolicy.java

@@ -26,107 +26,101 @@
  */
 package org.apache.http.impl.client.cache;
 
+import static org.junit.Assert.*;
+
 import java.util.Date;
 
 import org.apache.http.Header;
+import org.apache.http.HttpRequest;
+import org.apache.http.HttpVersion;
 import org.apache.http.client.cache.HttpCacheEntry;
 import org.apache.http.impl.cookie.DateUtils;
 import org.apache.http.message.BasicHeader;
-import org.junit.Assert;
+import org.apache.http.message.BasicHttpRequest;
+import org.junit.Before;
 import org.junit.Test;
 
 public class TestCacheValidityPolicy {
 
+    private CacheValidityPolicy impl;
+    private Date now;
+    private Date oneSecondAgo;
+    private Date sixSecondsAgo;
+    private Date tenSecondsAgo;
+    private Date elevenSecondsAgo;
+
+    @Before
+    public void setUp() {
+        impl = new CacheValidityPolicy();
+        now = new Date();
+        oneSecondAgo = new Date(now.getTime() - 1 * 1000L);
+        sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
+        tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
+        elevenSecondsAgo = new Date(now.getTime() - 11 * 1000L);
+    }
+
     @Test
     public void testApparentAgeIsMaxIntIfDateHeaderNotPresent() {
         Header[] headers = {
                 new BasicHeader("Server", "MockServer/1.0")
         };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(2147483648L, impl.getApparentAgeSecs(entry));
-        Assert.assertEquals(2147483648L, impl.getApparentAgeSecs(entry));
     }
 
     @Test
     public void testApparentAgeIsResponseReceivedTimeLessDateHeader() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
-
         Header[] headers = new Header[] { new BasicHeader("Date", DateUtils
                 .formatDate(tenSecondsAgo)) };
 
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, sixSecondsAgo, headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(4, impl.getApparentAgeSecs(entry));
-
-        Assert.assertEquals(4, impl.getApparentAgeSecs(entry));
     }
 
     @Test
     public void testNegativeApparentAgeIsBroughtUpToZero() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
-
         Header[] headers = new Header[] { new BasicHeader("Date", DateUtils
                 .formatDate(sixSecondsAgo)) };
-
         HttpCacheEntry entry  = HttpTestUtils.makeCacheEntry(now,tenSecondsAgo,headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(0, impl.getApparentAgeSecs(entry));
-        Assert.assertEquals(0, impl.getApparentAgeSecs(entry));
     }
 
     @Test
     public void testCorrectedReceivedAgeIsAgeHeaderIfLarger() {
         Header[] headers = new Header[] { new BasicHeader("Age", "10"), };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             protected long getApparentAgeSecs(HttpCacheEntry entry) {
                 return 6;
             }
-
         };
-
+        assertEquals(10, impl.getCorrectedReceivedAgeSecs(entry));
-        Assert.assertEquals(10, impl.getCorrectedReceivedAgeSecs(entry));
     }
 
     @Test
     public void testCorrectedReceivedAgeIsApparentAgeIfLarger() {
         Header[] headers = new Header[] { new BasicHeader("Age", "6"), };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             protected long getApparentAgeSecs(HttpCacheEntry entry) {
                 return 10;
             }
-
         };
-
+        assertEquals(10, impl.getCorrectedReceivedAgeSecs(entry));
-        Assert.assertEquals(10, impl.getCorrectedReceivedAgeSecs(entry));
     }
 
     @Test
     public void testResponseDelayIsDifferenceBetweenResponseAndRequestTimes() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(tenSecondsAgo, sixSecondsAgo);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(4, impl.getResponseDelaySecs(entry));
-
-        Assert.assertEquals(4, impl.getResponseDelaySecs(entry));
     }
 
     @Test
     public void testCorrectedInitialAgeIsCorrectedReceivedAgePlusResponseDelay() {
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
+        impl = new CacheValidityPolicy() {
-
             @Override
             protected long getCorrectedReceivedAgeSecs(HttpCacheEntry entry) {
                 return 7;
@@ -136,62 +130,50 @@ public class TestCacheValidityPolicy {
             protected long getResponseDelaySecs(HttpCacheEntry entry) {
                 return 13;
             }
-
         };
-        Assert.assertEquals(20, impl.getCorrectedInitialAgeSecs(entry));
+        assertEquals(20, impl.getCorrectedInitialAgeSecs(entry));
     }
 
     @Test
     public void testResidentTimeSecondsIsTimeSinceResponseTime() {
-        final Date now = new Date();
-        final Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, sixSecondsAgo);
-
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             protected Date getCurrentDate() {
                 return now;
             }
-
         };
-
+        assertEquals(6, impl.getResidentTimeSecs(entry, now));
-        Assert.assertEquals(6, impl.getResidentTimeSecs(entry, now));
     }
 
     @Test
     public void testCurrentAgeIsCorrectedInitialAgePlusResidentTime() {
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
+        impl = new CacheValidityPolicy() {
-
             @Override
             protected long getCorrectedInitialAgeSecs(HttpCacheEntry entry) {
                 return 11;
             }
-
             @Override
             protected long getResidentTimeSecs(HttpCacheEntry entry, Date d) {
                 return 17;
             }
         };
-        Assert.assertEquals(28, impl.getCurrentAgeSecs(entry, new Date()));
+        assertEquals(28, impl.getCurrentAgeSecs(entry, new Date()));
     }
 
     @Test
     public void testFreshnessLifetimeIsSMaxAgeIfPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "s-maxage=10") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
     public void testFreshnessLifetimeIsMaxAgeIfPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "max-age=10") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
@@ -199,312 +181,269 @@ public class TestCacheValidityPolicy {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "max-age=10"),
                 new BasicHeader("Cache-Control", "s-maxage=20") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
 
         headers = new Header[] { new BasicHeader("Cache-Control", "max-age=20"),
                 new BasicHeader("Cache-Control", "s-maxage=10") };
         entry = HttpTestUtils.makeCacheEntry(headers);
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
     public void testFreshnessLifetimeIsMaxAgeEvenIfExpiresIsPresent() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "max-age=10"),
                 new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                 new BasicHeader("Expires", DateUtils.formatDate(sixSecondsAgo)) };
 
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
     public void testFreshnessLifetimeIsSMaxAgeEvenIfExpiresIsPresent() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "s-maxage=10"),
                 new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                 new BasicHeader("Expires", DateUtils.formatDate(sixSecondsAgo)) };
 
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(10, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
     public void testFreshnessLifetimeIsFromExpiresHeaderIfNoMaxAge() {
-        Date now = new Date();
-        Date sixSecondsAgo = new Date(now.getTime() - 6 * 1000L);
-        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
         Header[] headers = new Header[] {
                 new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                 new BasicHeader("Expires", DateUtils.formatDate(sixSecondsAgo)) };
 
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(4, impl.getFreshnessLifetimeSecs(entry));
-        Assert.assertEquals(4, impl.getFreshnessLifetimeSecs(entry));
     }
 
     @Test
     public void testHeuristicFreshnessLifetime() {
-        Date now = new Date();
-        Date oneSecondAgo = new Date(now.getTime() - 1 * 1000L);
-        Date elevenSecondsAgo = new Date(now.getTime() - 11 * 1000L);
-
         Header[] headers = new Header[] {
                 new BasicHeader("Date", DateUtils.formatDate(oneSecondAgo)),
                 new BasicHeader("Last-Modified", DateUtils.formatDate(elevenSecondsAgo))
         };
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertEquals(1, impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, 0));
-        Assert.assertEquals(1, impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, 0));
     }
 
     @Test
     public void testHeuristicFreshnessLifetimeDefaultsProperly() {
         long defaultFreshness = 10;
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-
+        assertEquals(defaultFreshness, impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, defaultFreshness));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        Assert.assertEquals(defaultFreshness, impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, defaultFreshness));
     }
 
     @Test
     public void testHeuristicFreshnessLifetimeIsNonNegative() {
-        Date now = new Date();
-        Date oneSecondAgo = new Date(now.getTime() - 1 * 1000L);
-        Date elevenSecondsAgo = new Date(now.getTime() - 1 * 1000L);
-
         Header[] headers = new Header[] {
                 new BasicHeader("Date", DateUtils.formatDate(elevenSecondsAgo)),
                 new BasicHeader("Last-Modified", DateUtils.formatDate(oneSecondAgo))
         };
 
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertTrue(impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, 10) >= 0);
-        Assert.assertTrue(impl.getHeuristicFreshnessLifetimeSecs(entry, 0.1f, 10) >= 0);
     }
 
     @Test
     public void testResponseIsFreshIfFreshnessLifetimeExceedsCurrentAge() {
         final HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-        final Date now = new Date();
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             public long getCurrentAgeSecs(HttpCacheEntry e, Date d) {
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
-                Assert.assertEquals(now, d);
+                assertEquals(now, d);
                 return 6;
             }
-
             @Override
             public long getFreshnessLifetimeSecs(HttpCacheEntry e) {
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
                 return 10;
             }
         };
-
+        assertTrue(impl.isResponseFresh(entry, now));
-        Assert.assertTrue(impl.isResponseFresh(entry, now));
     }
 
     @Test
     public void testResponseIsNotFreshIfFreshnessLifetimeEqualsCurrentAge() {
         final HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-        final Date now = new Date();
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             public long getCurrentAgeSecs(HttpCacheEntry e, Date d) {
-                Assert.assertEquals(now, d);
+                assertEquals(now, d);
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
                 return 6;
             }
-
             @Override
             public long getFreshnessLifetimeSecs(HttpCacheEntry e) {
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
                 return 6;
             }
         };
-
+        assertFalse(impl.isResponseFresh(entry, now));
-        Assert.assertFalse(impl.isResponseFresh(entry, now));
     }
 
     @Test
     public void testResponseIsNotFreshIfCurrentAgeExceedsFreshnessLifetime() {
         final HttpCacheEntry entry = HttpTestUtils.makeCacheEntry();
-        final Date now = new Date();
+        impl = new CacheValidityPolicy() {
-        CacheValidityPolicy impl = new CacheValidityPolicy() {
-
             @Override
             public long getCurrentAgeSecs(HttpCacheEntry e, Date d) {
-                Assert.assertEquals(now, d);
+                assertEquals(now, d);
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
                 return 10;
             }
-
             @Override
             public long getFreshnessLifetimeSecs(HttpCacheEntry e) {
-                Assert.assertSame(entry, e);
+                assertSame(entry, e);
                 return 6;
             }
         };
-
+        assertFalse(impl.isResponseFresh(entry, now));
-        Assert.assertFalse(impl.isResponseFresh(entry, now));
     }
 
     @Test
     public void testCacheEntryIsRevalidatableIfHeadersIncludeETag() {
-
         Header[] headers = {
                 new BasicHeader("Expires", DateUtils.formatDate(new Date())),
                 new BasicHeader("ETag", "somevalue")};
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertTrue(impl.isRevalidatable(entry));
-
-        Assert.assertTrue(impl.isRevalidatable(entry));
     }
 
     @Test
     public void testCacheEntryIsRevalidatableIfHeadersIncludeLastModifiedDate() {
-
         Header[] headers = {
                 new BasicHeader("Expires", DateUtils.formatDate(new Date())),
                 new BasicHeader("Last-Modified", DateUtils.formatDate(new Date())) };
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertTrue(impl.isRevalidatable(entry));
-
-        Assert.assertTrue(impl.isRevalidatable(entry));
     }
 
     @Test
     public void testCacheEntryIsNotRevalidatableIfNoAppropriateHeaders() {
-
         Header[] headers =  {
                 new BasicHeader("Expires", DateUtils.formatDate(new Date())),
                 new BasicHeader("Cache-Control", "public") };
-
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertFalse(impl.isRevalidatable(entry));
-
-        Assert.assertFalse(impl.isRevalidatable(entry));
     }
 
     @Test
     public void testMalformedDateHeaderIsIgnored() {
-
         Header[] headers = new Header[] { new BasicHeader("Date", "asdf") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertNull(impl.getDateValue(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        Date d = impl.getDateValue(entry);
-
-        Assert.assertNull(d);
     }
 
     @Test
     public void testMalformedContentLengthReturnsNegativeOne() {
-
         Header[] headers = new Header[] { new BasicHeader("Content-Length", "asdf") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertEquals(-1, impl.getContentLengthValue(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        long length = impl.getContentLengthValue(entry);
-
-        Assert.assertEquals(-1, length);
     }
 
     @Test
     public void testNegativeAgeHeaderValueReturnsMaxAge() {
-
         Header[] headers = new Header[] { new BasicHeader("Age", "-100") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertEquals(CacheValidityPolicy.MAX_AGE, impl.getAgeValue(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        long length = impl.getAgeValue(entry);
-
-        Assert.assertEquals(CacheValidityPolicy.MAX_AGE, length);
     }
 
     @Test
     public void testMalformedAgeHeaderValueReturnsMaxAge() {
-
         Header[] headers = new Header[] { new BasicHeader("Age", "asdf") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertEquals(CacheValidityPolicy.MAX_AGE, impl.getAgeValue(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        long length = impl.getAgeValue(entry);
-
-        Assert.assertEquals(CacheValidityPolicy.MAX_AGE, length);
     }
 
     @Test
     public void testMalformedCacheControlMaxAgeHeaderReturnsZero() {
-
         Header[] headers = new Header[] { new BasicHeader("Cache-Control", "max-age=asdf") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertEquals(0, impl.getMaxAge(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        long maxage = impl.getMaxAge(entry);
-
-        Assert.assertEquals(0, maxage);
     }
 
     @Test
     public void testMalformedExpirationDateReturnsNull() {
         Header[] headers = new Header[] { new BasicHeader("Expires", "asdf") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-
+        assertNull(impl.getExpirationDate(entry));
-        CacheValidityPolicy impl = new CacheValidityPolicy();
-        Date expirationDate = impl.getExpirationDate(entry);
-
-        Assert.assertNull(expirationDate);
     }
 
     @Test
     public void testMustRevalidateIsFalseIfDirectiveNotPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control","public") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertFalse(impl.mustRevalidate(entry));
-
-        Assert.assertFalse(impl.mustRevalidate(entry));
     }
 
     @Test
     public void testMustRevalidateIsTrueWhenDirectiveIsPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control","public, must-revalidate") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertTrue(impl.mustRevalidate(entry));
-
-        Assert.assertTrue(impl.mustRevalidate(entry));
     }
 
     @Test
     public void testProxyRevalidateIsFalseIfDirectiveNotPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control","public") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertFalse(impl.proxyRevalidate(entry));
-
-        Assert.assertFalse(impl.proxyRevalidate(entry));
     }
 
     @Test
     public void testProxyRevalidateIsTrueWhenDirectiveIsPresent() {
         Header[] headers = new Header[] { new BasicHeader("Cache-Control","public, proxy-revalidate") };
         HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        CacheValidityPolicy impl = new CacheValidityPolicy();
+        assertTrue(impl.proxyRevalidate(entry));
-
-        Assert.assertTrue(impl.proxyRevalidate(entry));
     }
 
+    @Test
+    public void testMayReturnStaleIfErrorInResponseIsTrueWithinStaleness(){
+        Header[] headers = new Header[] {
+                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
+                new BasicHeader("Cache-Control", "max-age=5, stale-if-error=15")
+        };
+        HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, now, headers);
+        HttpRequest req = new BasicHttpRequest("GET","/",HttpVersion.HTTP_1_1);
+        assertTrue(impl.mayReturnStaleIfError(req, entry, now));
+    }
+
+    @Test
+    public void testMayReturnStaleIfErrorInRequestIsTrueWithinStaleness(){
+        Header[] headers = new Header[] {
+                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
+                new BasicHeader("Cache-Control", "max-age=5")
+        };
+        HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, now, headers);
+        HttpRequest req = new BasicHttpRequest("GET","/",HttpVersion.HTTP_1_1);
+        req.setHeader("Cache-Control","stale-if-error=15");
+        assertTrue(impl.mayReturnStaleIfError(req, entry, now));
+    }
+
+    @Test
+    public void testMayNotReturnStaleIfErrorInResponseAndAfterResponseWindow(){
+        Header[] headers = new Header[] {
+                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
+                new BasicHeader("Cache-Control", "max-age=5, stale-if-error=1")
+        };
+        HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, now, headers);
+        HttpRequest req = new BasicHttpRequest("GET","/",HttpVersion.HTTP_1_1);
+        assertFalse(impl.mayReturnStaleIfError(req, entry, now));
+    }
+
+    @Test
+    public void testMayNotReturnStaleIfErrorInResponseAndAfterRequestWindow(){
+        Header[] headers = new Header[] {
+                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
+                new BasicHeader("Cache-Control", "max-age=5")
+        };
+        HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(now, now, headers);
+        HttpRequest req = new BasicHttpRequest("GET","/",HttpVersion.HTTP_1_1);
+        req.setHeader("Cache-Control","stale-if-error=1");
+        assertFalse(impl.mayReturnStaleIfError(req, entry, now));
+    }
 }

httpclient-cache/src/test/java/org/apache/http/impl/client/cache/TestRFC5861Compliance.java

@@ -0,0 +1,157 @@
+/*
+ * ====================================================================
+ * 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.http.impl.client.cache;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Date;
+
+import org.apache.http.HttpRequest;
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.junit.Test;
+
+/** 
+ * A suite of acceptance tests for compliance with RFC5861, which
+ * describes the stale-if-error and stale-while-revalidate
+ * Cache-Control extensions.
+ */
+public class TestRFC5861Compliance extends AbstractProtocolTest {
+
+    /*	
+     * "The stale-if-error Cache-Control extension indicates that when an
+     * error is encountered, a cached stale response MAY be used to satisfy
+     * the request, regardless of other freshness information.When used as a 
+     * request Cache-Control extension, its scope of application is the request
+     * it appears in; when used as a response Cache-Control extension, its 
+     * scope is any request applicable to the cached response in which it 
+     * occurs.Its value indicates the upper limit to staleness; when the cached
+     * response is more stale than the indicated amount, the cached response
+     * SHOULD NOT be used to satisfy the request, absent other information.
+     * In this context, an error is any situation that would result in a
+     * 500, 502, 503, or 504 HTTP response status code being returned."
+     *  
+     * http://tools.ietf.org/html/rfc5861
+     */
+    @Test
+    public void testStaleIfErrorInResponseIsTrueReturnsStaleEntryWithWarning()
+    		throws Exception{
+        Date tenSecondsAgo = new Date(new Date().getTime() - 10 * 1000L);
+        HttpRequest req1 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp1 = HttpTestUtils.make200Response(tenSecondsAgo,
+        		"public, max-age=5, stale-if-error=60");
+        
+        backendExpectsAnyRequest().andReturn(resp1);
+
+        HttpRequest req2 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp2 = HttpTestUtils.make500Response();
+        
+        backendExpectsAnyRequest().andReturn(resp2);
+        
+        replayMocks();
+        impl.execute(host,req1);
+        HttpResponse result = impl.execute(host,req2);
+        verifyMocks();
+        
+        HttpTestUtils.assert110WarningFound(result);
+    }
+
+    @Test
+    public void testStaleIfErrorInRequestIsTrueReturnsStaleEntryWithWarning()
+    		throws Exception{
+        Date tenSecondsAgo = new Date(new Date().getTime() - 10 * 1000L);
+        HttpRequest req1 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp1 = HttpTestUtils.make200Response(tenSecondsAgo,
+        		"public, max-age=5");
+        
+        backendExpectsAnyRequest().andReturn(resp1);
+
+        HttpRequest req2 = HttpTestUtils.makeDefaultRequest();
+        req2.setHeader("Cache-Control","public, max-age=5, stale-if-error=60");
+        HttpResponse resp2 = HttpTestUtils.make500Response();
+        
+        backendExpectsAnyRequest().andReturn(resp2);
+        
+        replayMocks();
+        impl.execute(host,req1);
+        HttpResponse result = impl.execute(host,req2);
+        verifyMocks();
+        
+        HttpTestUtils.assert110WarningFound(result);
+    }
+    
+    @Test
+    public void testStaleIfErrorInResponseIsFalseReturnsError()
+    		throws Exception{
+    	Date now = new Date();
+        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
+        HttpRequest req1 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp1 = HttpTestUtils.make200Response(tenSecondsAgo,
+        		"public, max-age=5, stale-if-error=2");
+        
+        backendExpectsAnyRequest().andReturn(resp1);
+
+        HttpRequest req2 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp2 = HttpTestUtils.make500Response();
+        
+        backendExpectsAnyRequest().andReturn(resp2);
+        
+        replayMocks();
+        impl.execute(host,req1);
+        HttpResponse result = impl.execute(host,req2);
+        verifyMocks();
+
+        assertEquals(HttpStatus.SC_INTERNAL_SERVER_ERROR,
+                result.getStatusLine().getStatusCode());
+    }
+    
+    @Test
+    public void testStaleIfErrorInRequestIsFalseReturnsError()
+    		throws Exception{
+    	Date now = new Date();
+        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
+        HttpRequest req1 = HttpTestUtils.makeDefaultRequest();
+        HttpResponse resp1 = HttpTestUtils.make200Response(tenSecondsAgo,
+        		"public, max-age=5");
+        
+        backendExpectsAnyRequest().andReturn(resp1);
+
+        HttpRequest req2 = HttpTestUtils.makeDefaultRequest();
+        req2.setHeader("Cache-Control","stale-if-error=2");
+        HttpResponse resp2 = HttpTestUtils.make500Response();
+        
+        backendExpectsAnyRequest().andReturn(resp2);
+        
+        replayMocks();
+        impl.execute(host,req1);
+        HttpResponse result = impl.execute(host,req2);
+        verifyMocks();
+
+        assertEquals(HttpStatus.SC_INTERNAL_SERVER_ERROR,
+                result.getStatusLine().getStatusCode());
+    }
+}