From 9f71f8eb1cbd812ca9f2484619f63ec9cf2aafcf Mon Sep 17 00:00:00 2001
From: "Taro L. Saito" <leo@xerial.org>
Date: Wed, 6 Apr 2011 12:05:55 +0900
Subject: [PATCH] An attempt to use system class loader when loading dll

---
 pom.xml                                       |   7 +++
 .../java/org/xerial/snappy/LoadSnappy.java    |   4 +-
 src/main/java/org/xerial/snappy/Snappy.java   |  43 ++++++++++++++++++
 .../java/org/xerial/snappy/SnappyNative.java  |   3 --
 .../snappy/native/Windows/amd64/snappy.dll    | Bin 644608 -> 644608 bytes
 .../java/org/xerial/snappy/SnappyTest.java    |   7 ++-
 6 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/pom.xml b/pom.xml
index c6f648c..4cd0681 100755
--- a/pom.xml
+++ b/pom.xml
@@ -195,5 +195,12 @@
       <type>jar</type>
       <scope>test</scope>
     </dependency>
+    <dependency>
+    	<groupId>org.codehaus.plexus</groupId>
+    	<artifactId>plexus-classworlds</artifactId>
+    	<version>2.4</version>
+    	<type>jar</type>
+    	<scope>test</scope>
+    </dependency>
   </dependencies>
 </project>
diff --git a/src/main/java/org/xerial/snappy/LoadSnappy.java b/src/main/java/org/xerial/snappy/LoadSnappy.java
index aff7436..40ba313 100755
--- a/src/main/java/org/xerial/snappy/LoadSnappy.java
+++ b/src/main/java/org/xerial/snappy/LoadSnappy.java
@@ -48,8 +48,10 @@ public class LoadSnappy
     private static boolean isLoaded = false;
 
     public static boolean load() {
-        if (!isLoaded)
+        if (!isLoaded) {
+            ClassLoader cl = Thread.currentThread().getContextClassLoader();
             loadSnappyNativeLibrary();
+        }
         return isLoaded;
     }
 
diff --git a/src/main/java/org/xerial/snappy/Snappy.java b/src/main/java/org/xerial/snappy/Snappy.java
index 76f545d..6bbde4d 100755
--- a/src/main/java/org/xerial/snappy/Snappy.java
+++ b/src/main/java/org/xerial/snappy/Snappy.java
@@ -24,6 +24,9 @@
 //--------------------------------------
 package org.xerial.snappy;
 
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
 import java.nio.ByteBuffer;
 
 /**
@@ -35,6 +38,46 @@ import java.nio.ByteBuffer;
 public class Snappy
 {
 
+    static {
+        URL resource = Snappy.class.getResource("/org/xerial/snappy/SnappyNative.class");
+        // jar:file:/C:/.../snappy-java-1.0.1-rc4-SNAPSHOT.jar!/org/xerial/snappy/SnappyNative.class
+        if (resource == null) {
+            LoadSnappy.load();
+        }
+        else {
+            String path = resource.toString();
+            if (path.startsWith("jar:")) {
+                int pos = path.indexOf(".jar!");
+                if (pos >= 0) {
+                    path = path.substring(4, pos + 4);
+                }
+            }
+            else {
+                path = path.replace("SnappyNative", "LoadSnappy");
+            }
+            try {
+                URL loaderPath = new URL(path);
+                ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();
+                if (URLClassLoader.class.isInstance(systemClassLoader)) {
+
+                    URLClassLoader cl = URLClassLoader.class.cast(systemClassLoader);
+                    Method addURLmethod = URLClassLoader.class.getDeclaredMethod("addURL",
+                            new Class< ? >[] { URL.class });
+                    addURLmethod.setAccessible(true);
+
+                    addURLmethod.invoke(cl, loaderPath);
+                    Class< ? > snappyLoader = cl.loadClass("org.xerial.snappy.LoadSnappy");
+                    Method loader = snappyLoader.getMethod("load");
+                    loader.invoke(null);
+                }
+            }
+            catch (Exception e) {
+                e.printStackTrace();
+            }
+
+        }
+    }
+
     /**
      * Get the native library version of the snappy
      * 
diff --git a/src/main/java/org/xerial/snappy/SnappyNative.java b/src/main/java/org/xerial/snappy/SnappyNative.java
index 7b63851..7674e0c 100755
--- a/src/main/java/org/xerial/snappy/SnappyNative.java
+++ b/src/main/java/org/xerial/snappy/SnappyNative.java
@@ -34,9 +34,6 @@ import java.nio.ByteBuffer;
  */
 public class SnappyNative
 {
-    static {
-        LoadSnappy.load();
-    }
 
     public native static String nativeLibraryVersion();
 
diff --git a/src/main/resources/org/xerial/snappy/native/Windows/amd64/snappy.dll b/src/main/resources/org/xerial/snappy/native/Windows/amd64/snappy.dll
index aab93e0db43f58bd725bd7de4d749a8432e5598e..2da27c97e94fd74aaf62c201c10d46aceab8e9a8 100755
GIT binary patch
delta 60
zcmV-C0K@-)tS5l1Cy<B(<1v(xi%kRG;|YP=h1&sz+X98#1BKfJh1&&%+XjW(2Zh@R
Swc80PuLI&Sl(z@43Hc>lzZ=j1

delta 60
zcmV-C0K@-)tS5l1Cy<B(E-IOki%kQ4)Cz&yh1&sz+X98#1BKfJh1&&%+XjW(2Zh@R
Swc80PuLCVAnYRb93Hc=+&KdIn

diff --git a/src/test/java/org/xerial/snappy/SnappyTest.java b/src/test/java/org/xerial/snappy/SnappyTest.java
index 6412275..0a7cb6c 100755
--- a/src/test/java/org/xerial/snappy/SnappyTest.java
+++ b/src/test/java/org/xerial/snappy/SnappyTest.java
@@ -210,7 +210,12 @@ public class SnappyTest
         byte[] compressed = Snappy.compress(input.getBytes("UTF-8"));
         byte[] uncompressed = Snappy.uncompress(compressed);
         String result = new String(uncompressed, "UTF-8");
-        System.out.println(result);
+        _logger.debug(result);
+
+    }
+
+    @Test
+    public void loadByDifferentClassLoader() throws Exception {
 
     }