From 787749988f028ae16aef055346d6fee707f0d5bf Mon Sep 17 00:00:00 2001
From: James Roper <jroper@vz.net>
Date: Tue, 3 Jan 2012 20:43:57 +0100
Subject: [PATCH] Added support for leading versions from maven pom.properties
 files

---
 .../jackson/core/util/VersionUtil.java        | 36 +++++++++++++++++++
 .../jackson/core/util/TestVersionUtil.java    |  6 +++-
 .../maven/foo/bar/foo-bar/pom.properties      |  3 ++
 3 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 src/test/resources/META-INF/maven/foo/bar/foo-bar/pom.properties

diff --git a/src/main/java/com/fasterxml/jackson/core/util/VersionUtil.java b/src/main/java/com/fasterxml/jackson/core/util/VersionUtil.java
index fc084e1fcd..a70913d8de 100644
--- a/src/main/java/com/fasterxml/jackson/core/util/VersionUtil.java
+++ b/src/main/java/com/fasterxml/jackson/core/util/VersionUtil.java
@@ -1,6 +1,7 @@
 package com.fasterxml.jackson.core.util;
 
 import java.io.*;
+import java.util.Properties;
 import java.util.regex.Pattern;
 
 import com.fasterxml.jackson.core.Version;
@@ -97,6 +98,41 @@ public static Version versionFor(Class<?> cls)
         return (version == null) ? Version.unknownVersion() : version;
     }
 
+    /**
+     * Will attempt to load the maven version for the given groupId and
+     * artifactId.  Maven puts a pom.properties file in
+     * META-INF/maven/groupId/artifactId, containing the groupId,
+     * artifactId and version of the library.
+     *
+     * @param classLoader the ClassLoader to load the pom.properties file from
+     * @param groupId the groupId of the library
+     * @param artifactId the artifactId of the library
+     * @return The version
+     */
+    public static Version mavenVersionFor(ClassLoader classLoader, String groupId, String artifactId) {
+        InputStream pomPoperties = classLoader.getResourceAsStream("META-INF/maven/" + groupId.replaceAll("\\.", "/")
+                + "/" + artifactId + "/pom.properties");
+        if (pomPoperties != null) {
+            try {
+                Properties props = new Properties();
+                props.load(pomPoperties);
+                String versionStr = props.getProperty("version");
+                String pomPropertiesArtifactId = props.getProperty("artifactId");
+                String pomPropertiesGroupId = props.getProperty("groupId");
+                return parseVersion(versionStr, pomPropertiesGroupId, pomPropertiesArtifactId);
+            } catch (IOException e) {
+                // Ignore
+            } finally {
+                try {
+                    pomPoperties.close();
+                } catch (IOException e) {
+                    // Ignore
+                }
+            }
+        }
+        return Version.unknownVersion();
+    }
+
     /**
      * Use variant that takes three arguments instead
      * 
diff --git a/src/test/java/com/fasterxml/jackson/core/util/TestVersionUtil.java b/src/test/java/com/fasterxml/jackson/core/util/TestVersionUtil.java
index 05a4a5c3bc..f52d1773fc 100644
--- a/src/test/java/com/fasterxml/jackson/core/util/TestVersionUtil.java
+++ b/src/test/java/com/fasterxml/jackson/core/util/TestVersionUtil.java
@@ -1,7 +1,6 @@
 package com.fasterxml.jackson.core.util;
 
 import com.fasterxml.jackson.core.Version;
-import com.fasterxml.jackson.core.util.VersionUtil;
 
 public class TestVersionUtil extends com.fasterxml.jackson.test.BaseTest
 {
@@ -16,4 +15,9 @@ public void testVersionParsing()
     {
         assertEquals(new Version(1, 2, 15, "foo"), VersionUtil.parseVersion("1.2.15-foo"));
     }
+
+    public void testMavenVersionParsing() {
+        assertEquals(new Version(1, 2, 3, "SNAPSHOT", "foo.bar", "foo-bar"),
+                VersionUtil.mavenVersionFor(TestVersionUtil.class.getClassLoader(), "foo.bar", "foo-bar"));
+    }
 }
diff --git a/src/test/resources/META-INF/maven/foo/bar/foo-bar/pom.properties b/src/test/resources/META-INF/maven/foo/bar/foo-bar/pom.properties
new file mode 100644
index 0000000000..5ae4d1680a
--- /dev/null
+++ b/src/test/resources/META-INF/maven/foo/bar/foo-bar/pom.properties
@@ -0,0 +1,3 @@
+groupId=foo.bar
+artifactId=foo-bar
+version=1.2.3-SNAPSHOT
\ No newline at end of file