[ABDERA-259] NullPointerException happens when trying to decode HEAD response

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.4.0, 1.0
• Assignee: Christine Koppelt
• Reporter: Tong Xiang Fan
• Created: 20/Jul/10 08:37
• Updated: 30/Jan/11 11:34
• Resolved: 30/Jan/11 11:34

Description

The client code sends HEAD request to HTTP server. The Content-Encoding header is not null so it tries to decode the response. However httpclient HeadMethod returns null as response body stream. Hence NullPointerException happens.

java.lang.NullPointerException
at java.util.zip.InflaterInputStream.<init>(InflaterInputStream.java:91)
at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:81)
at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:93)
at org.apache.abdera.util.CompressionUtil.getDecodingInputStream(CompressionUtil.java:71)
at org.apache.abdera.protocol.util.EncodingUtil.getDecodingInputStream(EncodingUtil.java:160)
at org.apache.abdera.protocol.client.CommonsResponse.getInputStream(CommonsResponse.java:156)
at org.apache.abdera.protocol.client.cache.InMemoryCachedResponse.<init>(InMemoryCachedResponse.java:55)
at org.apache.abdera.protocol.client.cache.InMemoryCache.createCachedResponse(InMemoryCache.java:44)
at org.apache.abdera.protocol.client.cache.AbstractCache.update(AbstractCache.java:142)
at org.apache.abdera.protocol.client.cache.AbstractCache.update(AbstractCache.java:130)
at org.apache.abdera.protocol.client.AbderaClient.execute(AbderaClient.java:698)
at org.apache.abdera.protocol.client.AbderaClient.head(AbderaClient.java:167)
at org.apache.abdera.protocol.client.AbderaClient.head(AbderaClient.java:344)

Sample response:

Date: Tue, 20 Jul 2010 07:53:08 GMT
Server: IBM_HTTP_Server/6.1 Apache/2.0.47 (Win32)
Expires: Thu, 1 Jan 1970 00:00:00 GMT
Cache-Control: no-store, no-cache, must-revalidate
Pragma: no-cache
Vary: Accept-Encoding
Content-Encoding: gzip
Keep-Alive: timeout=10, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html; charset=UTF-8
Content-Language: en-US

org.apache.abdera.protocol.client.CommonsResponse:

public InputStream getInputStream() throws IOException {
if (in == null)

{ String ce = getHeader("Content-Encoding"); in = method.getResponseBodyAsStream(); // returns null if method is HEAD if (ce != null) in = EncodingUtil.getDecodingInputStream(in, ce); in = new AutoReleasingInputStream(method,in); }

return in;
}