Maven classloader

This will allow us to test different versions of the client.

Also includes some extra methods to make it easier to work with the
bookkeeper client.

Master Issue: apache#903

Author: Ivan Kelly <[email protected]>
Author: Sijie Guo <[email protected]>

Reviewers: Enrico Olivelli <[email protected]>, Sijie Guo <[email protected]>

This closes apache#975 from ivankelly/maven-classloader

tests/integration-tests-utils/pom.xml

@@ -34,6 +34,7 @@
   <name>Apache BookKeeper :: Tests :: Utility module for Arquillian based integration tests</name>
 
   <properties>
+    <shrinkwrap.version>3.0.1</shrinkwrap.version>
     <arquillian-cube.version>1.13.0</arquillian-cube.version>
     <commons-compress.version>1.15</commons-compress.version>
   </properties>
@@ -45,6 +46,17 @@
       <version>${commons-compress.version}</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.jboss.shrinkwrap.resolver</groupId>
+      <artifactId>shrinkwrap-resolver-impl-maven</artifactId>
+      <version>${shrinkwrap.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.jboss.shrinkwrap.resolver</groupId>
+      <artifactId>shrinkwrap-resolver-api</artifactId>
+      <version>${shrinkwrap.version}</version>
+    </dependency>
+
     <dependency>
       <groupId>org.apache.zookeeper</groupId>
       <artifactId>zookeeper</artifactId>
@@ -81,4 +93,20 @@
     </dependency>
 
   </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <configuration>
+          <!-- forkCount=0 forces tests to run in isolated classloaders
+               which is required if want to test maven classloader without
+               test deps interfering //-->
+          <forkCount>0</forkCount>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
 </project>

tests/integration-tests-utils/src/main/java/org/apache/bookkeeper/tests/MavenClassLoader.java

@@ -0,0 +1,117 @@
+/**
+ *
+ * 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.
+ *
+ */
+package org.apache.bookkeeper.tests;
+
+import com.google.common.collect.Lists;
+
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+
+import org.jboss.shrinkwrap.resolver.api.maven.Maven;
+import org.jboss.shrinkwrap.resolver.api.maven.ScopeType;
+import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenDependencies;
+import org.jboss.shrinkwrap.resolver.api.maven.coordinate.MavenDependency;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MavenClassLoader implements AutoCloseable {
+    private static final Logger LOG = LoggerFactory.getLogger(MavenClassLoader.class);
+
+    private MavenClassLoader(URLClassLoader cl) {
+        this.classloader = cl;
+    }
+
+    private final URLClassLoader classloader;
+
+    public static MavenClassLoader forArtifact(String mainArtifact) throws Exception {
+        Optional<String> slf4jVersion = Arrays.stream(Maven.resolver().resolve(mainArtifact)
+                                                      .withTransitivity().asResolvedArtifact())
+            .filter((a) -> a.getCoordinate().getGroupId().equals("org.slf4j")
+                    && a.getCoordinate().getArtifactId().equals("slf4j-log4j12"))
+            .map((a) -> a.getCoordinate().getVersion())
+            .findFirst();
+
+        List<MavenDependency> deps = Lists.newArrayList(
+                MavenDependencies.createDependency(
+                        mainArtifact, ScopeType.COMPILE, false,
+                        MavenDependencies.createExclusion("org.slf4j:slf4j-log4j12"),
+                        MavenDependencies.createExclusion("log4j:log4j")));
+        if (slf4jVersion.isPresent()) {
+            deps.add(MavenDependencies.createDependency("org.slf4j:slf4j-simple:" + slf4jVersion.get(),
+                                                        ScopeType.COMPILE, false));
+        }
+
+        File[] files = Maven.resolver().addDependencies(deps.toArray(new MavenDependency[0]))
+            .resolve().withTransitivity().asFile();
+        URLClassLoader cl = AccessController.doPrivileged(
+                new PrivilegedAction<URLClassLoader>() {
+                    @Override
+                    public URLClassLoader run() {
+                        return new URLClassLoader(Arrays.stream(files)
+                                                  .map((f) -> {
+                                                          try {
+                                                              return f.toURI().toURL();
+                                                          } catch (Throwable t) {
+                                                              throw new RuntimeException(t);
+                                                          }
+                                                      })
+                                                  .toArray(URL[]::new),
+                                                  ClassLoader.getSystemClassLoader());
+                    }
+                });
+        return new MavenClassLoader(cl);
+    }
+
+    public static MavenClassLoader forBookKeeperVersion(String version) throws Exception {
+        return forArtifact("org.apache.bookkeeper:bookkeeper-server:" +  version);
+    }
+
+    public Object newInstance(String className, Object... args) throws Exception {
+        Class<?> klass = Class.forName(className, true, classloader);
+        return klass.getConstructor(Arrays.stream(args).map((a)-> a.getClass()).toArray(Class[]::new))
+            .newInstance(args);
+    }
+
+    public Object newBookKeeper(String zookeeper) throws Exception {
+        return newInstance("org.apache.bookkeeper.client.BookKeeper", zookeeper);
+    }
+
+    public Object digestType(String type) throws Exception {
+        String className = "org.apache.bookkeeper.client.BookKeeper$DigestType";
+        for (Object o : classloader.loadClass(className).getEnumConstants()) {
+            if (o.toString().equals(type)) {
+                return o;
+            }
+        }
+        throw new ClassNotFoundException("No such digest type " + type);
+    }
+
+    public void close() throws Exception {
+        classloader.close();
+    }
+}

tests/integration-tests-utils/src/test/java/org/apache/bookkeeper/tests/MavenClassLoaderTest.java

@@ -0,0 +1,42 @@
+/**
+ *
+ * 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.
+ *
+ */
+package org.apache.bookkeeper.tests;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class MavenClassLoaderTest {
+    @Test(expected=ClassNotFoundException.class)
+    public void testLog4JReplacement() throws Exception {
+        MavenClassLoader.forBookKeeperVersion("4.0.0")
+            .newInstance("org.apache.log4j.Logger");
+    }
+
+    @Test
+    public void testNoZooKeeperInterference() throws Exception {
+        // Use KeeperException, because ZooKeeper needs a watcher which would be a pain to construct
+        Object o = MavenClassLoader.forBookKeeperVersion("4.0.0")
+            .newInstance("org.apache.zookeeper.KeeperException$NoNodeException");
+        Assert.assertFalse(o.getClass().equals(
+                                   org.apache.zookeeper.KeeperException.NoNodeException.class));
+    }
+
+}