HTTPCLIENT-1213: Avoid parsing HttpCacheEntry date attribute multiple times.

Contributed by Sam Perman <sam at permans.com>

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1463551 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -37,7 +37,10 @@ import org.apache.http.HttpResponse;
 import org.apache.http.ProtocolVersion;
 import org.apache.http.StatusLine;
 import org.apache.http.annotation.Immutable;
+import org.apache.http.impl.cookie.DateParseException;
+import org.apache.http.impl.cookie.DateUtils;
 import org.apache.http.message.HeaderGroup;
+import org.apache.http.protocol.HTTP;
 import org.apache.http.util.Args;
 
 /**
@@ -60,6 +63,7 @@ public class HttpCacheEntry implements Serializable {
     private final HeaderGroup responseHeaders;
     private final Resource resource;
     private final Map<String,String> variantMap;
+    private final Date date;
 
     /**
      * Create a new {@link HttpCacheEntry} with variants.
@@ -100,6 +104,7 @@ public class HttpCacheEntry implements Serializable {
         this.variantMap = variantMap != null
             ? new HashMap<String,String>(variantMap)
             : null;
+        this.date = parseDate();
     }
 
     /**
@@ -123,6 +128,22 @@ public class HttpCacheEntry implements Serializable {
                 new HashMap<String,String>());
     }
 
+    /**
+     * Find the "Date" response header and parse it into a java.util.Date
+     * @return the Date value of the header or null if the header is not present
+     */
+    private Date parseDate() {
+        final Header dateHdr = getFirstHeader(HTTP.DATE_HEADER);
+        if (dateHdr == null)
+            return null;
+        try {
+            return DateUtils.parseDate(dateHdr.getValue());
+        } catch (final DateParseException dpe) {
+            // ignore malformed date
+        }
+        return null;
+    }
+
     /**
      * Returns the {@link StatusLine} from the origin {@link HttpResponse}.
      */
@@ -192,6 +213,16 @@ public class HttpCacheEntry implements Serializable {
         return responseHeaders.getHeaders(name);
     }
 
+    /**
+     * Gets the Date value of the "Date" header or null if the header is missing or cannot be
+     * parsed.
+     *
+     * @since 4.3
+     */
+    public Date getDate() {
+        return date;
+    }
+
     /**
      * Returns the {@link Resource} containing the origin response body.
      */
@@ -231,4 +262,5 @@ public class HttpCacheEntry implements Serializable {
         return "[request date=" + this.requestDate + "; response date=" + this.responseDate
                 + "; statusLine=" + this.statusLine + "]";
     }
+
 }

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

@@ -60,7 +60,7 @@ class CacheValidityPolicy {
             return maxage;
         }
 
-        final Date dateValue = getDateValue(entry);
+        final Date dateValue = entry.getDate();
         if (dateValue == null) {
             return 0L;
         }
@@ -97,7 +97,7 @@ class CacheValidityPolicy {
 
     public long getHeuristicFreshnessLifetimeSecs(final HttpCacheEntry entry,
             final float coefficient, final long defaultLifetime) {
-        final Date dateValue = getDateValue(entry);
+        final Date dateValue = entry.getDate();
         final Date lastModifiedValue = getLastModifiedValue(entry);
 
         if (dateValue != null && lastModifiedValue != null) {
@@ -172,17 +172,14 @@ class CacheValidityPolicy {
         return result;
     }
 
+    /**
+     * @deprecated (4.3) use {@link HttpCacheEntry#getDate()}.
+     * @param entry
+     * @return
+     */
+    @Deprecated
     protected Date getDateValue(final HttpCacheEntry entry) {
-        final Header dateHdr = entry.getFirstHeader(HTTP.DATE_HEADER);
-        if (dateHdr == null) {
-            return null;
-        }
-        try {
-            return DateUtils.parseDate(dateHdr.getValue());
-        } catch (final DateParseException dpe) {
-            // ignore malformed date
-        }
-        return null;
+        return entry.getDate();
     }
 
     protected Date getLastModifiedValue(final HttpCacheEntry entry) {
@@ -227,7 +224,7 @@ class CacheValidityPolicy {
     }
 
     protected long getApparentAgeSecs(final HttpCacheEntry entry) {
-        final Date dateValue = getDateValue(entry);
+        final Date dateValue = entry.getDate();
         if (dateValue == null) {
             return MAX_AGE;
         }

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

@@ -30,6 +30,7 @@ import static org.easymock.classextension.EasyMock.createNiceMock;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
@@ -304,4 +305,34 @@ public class TestHttpCacheEntry {
         assertNotNull(entry.toString());
         assertFalse("".equals(entry.toString()));
     }
+
+    @Test
+    public void testMissingDateHeaderIsIgnored() {
+        final Header[] headers = new Header[] {};
+        entry = new HttpCacheEntry(new Date(), new Date(), statusLine,
+                                   headers, mockResource);
+        assertNull(entry.getDate());
+    }
+
+    @Test
+    public void testMalformedDateHeaderIsIgnored() {
+        final Header[] headers = new Header[] { new BasicHeader("Date", "asdf") };
+        entry = new HttpCacheEntry(new Date(), new Date(), statusLine,
+                                   headers, mockResource);
+        assertNull(entry.getDate());
+    }
+
+    @Test
+    public void testValidDateHeaderIsParsed() {
+        final long now = System.currentTimeMillis();
+        // round down to nearest second to make comparison easier
+        final Date date = new Date(now - (now % 1000L));
+        final Header[] headers = new Header[] { new BasicHeader("Date", DateUtils.formatDate(date)) };
+        entry = new HttpCacheEntry(new Date(), new Date(), statusLine,
+                                   headers, mockResource);
+        final Date dateHeaderValue = entry.getDate();
+        assertNotNull(dateHeaderValue);
+        assertEquals(date.getTime(), dateHeaderValue.getTime());
+    }
+
 }

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

@@ -355,13 +355,6 @@ public class TestCacheValidityPolicy {
         assertFalse(impl.contentLengthHeaderMatchesActualLength(entry));
     }
 
-    @Test
-    public void testMalformedDateHeaderIsIgnored() {
-        final Header[] headers = new Header[] { new BasicHeader("Date", "asdf") };
-        final HttpCacheEntry entry = HttpTestUtils.makeCacheEntry(headers);
-        assertNull(impl.getDateValue(entry));
-    }
-
     @Test
     public void testMalformedContentLengthReturnsNegativeOne() {
         final Header[] headers = new Header[] { new BasicHeader("Content-Length", "asdf") };