Merge pull request cdapio#15049 from cdapio/CDAP-20548-consolidate-cl…

…asspath-logic

CDAP-20548 fix MainClassLoader class path logic

cdap-common/src/main/java/io/cdap/cdap/common/app/MainClassLoader.java

@@ -21,6 +21,7 @@
 import io.cdap.cdap.api.dataset.Dataset;
 import io.cdap.cdap.common.dataset.DatasetClassRewriter;
 import io.cdap.cdap.common.lang.ClassLoaders;
+import io.cdap.cdap.common.lang.ClassPathResources;
 import io.cdap.cdap.common.lang.CombineClassLoader;
 import io.cdap.cdap.common.lang.FilterClassLoader;
 import io.cdap.cdap.common.lang.GuavaClassRewriter;
@@ -104,11 +105,8 @@ public static MainClassLoader createFromContext(FilterClassLoader.Filter filter,
 
     if (classLoader instanceof URLClassLoader) {
       classpath.addAll(Arrays.asList(((URLClassLoader) classLoader).getURLs()));
-    } else if (classLoader == ClassLoader.getSystemClassLoader()) {
-      addClassPath(classpath);
     } else {
-      // No able to create a new MainClassLoader
-      return null;
+      classpath.addAll(ClassPathResources.getClasspathUrls());
     }
 
     classpath.addAll(Arrays.asList(extraClasspath));
@@ -180,27 +178,6 @@ public byte[] rewriteClass(String className, InputStream input) throws IOExcepti
     return rewrittenCode;
   }
 
-  /**
-   * Adds {@link URL} to the given list based on the system classpath.
-   */
-  private static void addClassPath(List<URL> urls) {
-    String wildcardSuffix = File.pathSeparator + "*";
-    // In case the system classloader is not a URLClassLoader, use the classpath property (maybe from non Oracle JDK)
-    for (String path : Splitter.on(File.pathSeparatorChar)
-        .split(System.getProperty("java.class.path"))) {
-      if ("*".equals(path) || path.endsWith(wildcardSuffix)) {
-        for (File jarFile : DirUtils.listFiles(new File(path), "jar")) {
-          try {
-            urls.add(jarFile.toURI().toURL());
-          } catch (MalformedURLException e) {
-            // Shouldn't happen. Propagate the exception.
-            throw Throwables.propagate(e);
-          }
-        }
-      }
-    }
-  }
-
   private boolean isRewriteNeeded(String className) throws IOException {
     return guavaClassRewriter.needRewrite(className)
         || levelDBClassRewriter.needRewrite(className)

cdap-common/src/main/java/io/cdap/cdap/common/lang/ClassPathResources.java

@@ -19,14 +19,19 @@
 import io.cdap.cdap.common.internal.guava.ClassPath;
 import io.cdap.cdap.common.internal.guava.ClassPath.ClassInfo;
 import io.cdap.cdap.common.internal.guava.ClassPath.ResourceInfo;
+import java.io.File;
 import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Paths;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
 import org.apache.twill.api.ClassAcceptor;
@@ -41,6 +46,33 @@ public final class ClassPathResources {
 
   private static final Logger LOG = LoggerFactory.getLogger(ClassPathResources.class);
 
+  /**
+   * Return a list of all URL entries from the java class path.
+   *
+   * @return list of all URL entries from the java class path.
+   */
+  public static List<URL> getClasspathUrls() {
+    List<URL> urls = new ArrayList<>();
+
+    // wildcards are expanded before they are places in java.class.path
+    // for example, java -cp lib/* will list out all the jars in the lib directory and
+    // add each individual jars as an element in java.class.path. The exception is if
+    // the directory doesn't exist, then it will be preserved as lib/*.
+    for (String path : System.getProperty("java.class.path").split(File.pathSeparator)) {
+      try {
+        urls.add(Paths.get(path).toRealPath().toUri().toURL());
+      } catch (NoSuchFileException e) {
+        // ignore anything that doesn't exist
+      } catch (MalformedURLException e) {
+        // should never happen
+        throw new RuntimeException(e);
+      } catch (IOException e) {
+        throw new RuntimeException("Unable to get class path entry " + path, e);
+      }
+    }
+    return urls;
+  }
+
   /**
    * Returns the base set of resources needed to load the specified {@link Class} using the
    * specified {@link ClassLoader}. Also traces and includes the dependencies for the specified

cdap-runtime-ext-dataproc/src/main/java/io/cdap/cdap/runtime/spi/runtimejob/DataprocJobMain.java

@@ -24,6 +24,7 @@
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -181,7 +182,11 @@ private static URL[] getClasspath(List<String> jarFiles) throws IOException {
 
     // Add the system class path to the URL list
     for (String path : System.getProperty("java.class.path").split(File.pathSeparator)) {
-      urls.add(Paths.get(path).toRealPath().toUri().toURL());
+      try {
+        urls.add(Paths.get(path).toRealPath().toUri().toURL());
+      } catch (NoSuchFileException e) {
+        // ignore anything that doesn't exist
+      }
     }
 
     return urls.toArray(new URL[0]);

cdap-spark-core-base/src/main/java/io/cdap/cdap/app/runtime/spark/distributed/SparkContainerLauncher.java

@@ -22,11 +22,11 @@
 import io.cdap.cdap.app.runtime.spark.classloader.SparkContainerClassLoader;
 import io.cdap.cdap.app.runtime.spark.python.SparkPythonUtil;
 import io.cdap.cdap.common.lang.ClassLoaders;
+import io.cdap.cdap.common.lang.ClassPathResources;
 import io.cdap.cdap.common.lang.FilterClassLoader;
 import io.cdap.cdap.common.logging.StandardOutErrorRedirector;
 import io.cdap.cdap.common.logging.common.UncaughtExceptionHandler;
 import java.io.Closeable;
-import java.io.File;
 import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URI;
@@ -102,9 +102,7 @@ public static void launch(String mainClassName, String[] args, boolean removeMai
     Thread.setDefaultUncaughtExceptionHandler(new UncaughtExceptionHandler());
 
     Set<URL> urls = new LinkedHashSet<>();
-    for (String path : System.getProperty("java.class.path").split(File.pathSeparator)) {
-      urls.add(Paths.get(path).toRealPath().toUri().toURL());
-    }
+    urls.addAll(ClassPathResources.getClasspathUrls());
 
     ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();