BugID 44240 factor out classpath support from JavaResource into an Abstract resource

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@612078 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/types/resources/AbstractClasspathResource.java

@@ -0,0 +1,164 @@
+/*
+ * Copyright  2007 The Apache Software Foundation
+ *
+ *  Licensed 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.tools.ant.types.resources;
+
+import org.apache.tools.ant.types.Resource;
+import org.apache.tools.ant.types.Path;
+import org.apache.tools.ant.types.Reference;
+import org.apache.tools.ant.util.FileUtils;
+
+import java.io.InputStream;
+import java.io.IOException;
+
+/**
+ *
+ * A Resource representation of anything thta is accessed via a Java classloader.
+ * The core methods to set/resolve the classpath are provided, and
+ * @since Ant 1.8
+ *
+ */
+
+public abstract class AbstractClasspathResource extends Resource {
+    protected Path classpath;
+    protected Reference loader;
+
+    /**
+     * Set the classpath to use when looking up a resource.
+     * @param classpath to add to any existing classpath
+     */
+    public void setClasspath(Path classpath) {
+        checkAttributesAllowed();
+        if (this.classpath == null) {
+            this.classpath = classpath;
+        } else {
+            this.classpath.append(classpath);
+        }
+    }
+
+    /**
+     * Add a classpath to use when looking up a resource.
+     * @return The classpath to be configured
+     */
+    public Path createClasspath() {
+        checkChildrenAllowed();
+        if (classpath == null) {
+            classpath = new Path(getProject());
+        }
+        return classpath.createPath();
+    }
+
+    /**
+     * Set the classpath to use when looking up a resource,
+     * given as reference to a <path> defined elsewhere
+     * @param r The reference value
+     */
+    public void setClasspathRef(Reference r) {
+        checkAttributesAllowed();
+        createClasspath().setRefid(r);
+    }
+
+    /**
+     * get the classpath used by this <code>LoadProperties</code>.
+     * @return The classpath
+     */
+    public Path getClasspath() {
+        return isReference()
+            ? ((JavaResource) getCheckedRef()).getClasspath() : classpath;
+    }
+
+    /**
+     * Use the reference to locate the loader. If the loader is not
+     * found, taskdef will use the specified classpath and register it
+     * with the specified name.
+     *
+     * This allow multiple taskdef/typedef to use the same class loader,
+     * so they can be used together. It eliminate the need to
+     * put them in the CLASSPATH.
+     *
+     * @param r the reference to locate the loader.
+     */
+    public void setLoaderRef(Reference r) {
+        checkAttributesAllowed();
+        loader = r;
+    }
+
+    /**
+     * Overrides the super version.
+     * @param r the Reference to set.
+     */
+    public void setRefid(Reference r) {
+        if (loader != null || classpath != null) {
+            throw tooManyAttributes();
+        }
+        super.setRefid(r);
+    }
+
+    /**
+     * Learn whether this resource exists. This implementation opens the input stream
+     * as the test.
+     * @return true if this resource exists.
+     */
+    public boolean isExists() {
+        if (isReference()) {
+            return  ((Resource) getCheckedRef()).isExists();
+        }
+        InputStream is = null;
+        try {
+            is = getInputStream();
+            return is != null;
+        } catch (IOException ex) {
+            return false;
+        } finally {
+            FileUtils.close(is);
+        }
+    }
+
+    /**
+     * Return an InputStream for reading the contents of this Resource.
+     * @return an InputStream object.
+     * @throws IOException if an error occurs.
+     */
+    public InputStream getInputStream() throws IOException {
+        if (isReference()) {
+            return ((Resource) getCheckedRef()).getInputStream();
+        }
+        ClassLoader cl = null;
+        if (loader != null) {
+            cl = (ClassLoader) loader.getReferencedObject();
+        }
+        if (cl == null) {
+            if (getClasspath() != null) {
+                cl = getProject().createClassLoader(classpath);
+            } else {
+                cl = JavaResource.class.getClassLoader();
+            }
+            if (loader != null && cl != null) {
+                getProject().addReference(loader.getRefId(), cl);
+            }
+        }
+
+        return openInputStream(cl);
+    }
+
+    /**
+     * open the inpout stream from a specific classloader
+     * @param cl the classloader to use. Will be null if the system classloader is used
+     * @return an open input stream for the resource
+     * @throws IOException if an error occurs.
+     */
+    protected abstract InputStream openInputStream(ClassLoader cl) throws IOException;
+}

src/main/org/apache/tools/ant/types/resources/JavaResource.java

@@ -29,10 +29,7 @@ import org.apache.tools.ant.types.Reference;
  * A Resource representation of something loadable via a Java classloader.
  * @since Ant 1.7
  */
-public class JavaResource extends Resource {
-
-    private Path classpath;
-    private Reference loader;
+public class JavaResource extends AbstractClasspathResource {
 
     /**
      * Default constructor.
@@ -53,119 +50,12 @@ public class JavaResource extends Resource {
     }
 
     /**
-     * Set the classpath to use when looking up a resource.
-     * @param classpath to add to any existing classpath
-     */
-    public void setClasspath(Path classpath) {
-        checkAttributesAllowed();
-        if (this.classpath == null) {
-            this.classpath = classpath;
-        } else {
-            this.classpath.append(classpath);
-        }
-    }
-
-    /**
-     * Add a classpath to use when looking up a resource.
-     * @return The classpath to be configured
-     */
-    public Path createClasspath() {
-        checkChildrenAllowed();
-        if (this.classpath == null) {
-            this.classpath = new Path(getProject());
-        }
-        return this.classpath.createPath();
-    }
-
-    /**
-     * Set the classpath to use when looking up a resource,
-     * given as reference to a <path> defined elsewhere
-     * @param r The reference value
-     */
-    public void setClasspathRef(Reference r) {
-        checkAttributesAllowed();
-        createClasspath().setRefid(r);
-    }
-
-    /**
-     * get the classpath used by this <code>LoadProperties</code>.
-     * @return The classpath
-     */
-    public Path getClasspath() {
-        return isReference()
-            ? ((JavaResource) getCheckedRef()).getClasspath() : classpath;
-    }
-
-    /**
-     * Use the reference to locate the loader. If the loader is not
-     * found, taskdef will use the specified classpath and register it
-     * with the specified name.
-     *
-     * This allow multiple taskdef/typedef to use the same class loader,
-     * so they can be used together. It eliminate the need to
-     * put them in the CLASSPATH.
-     *
-     * @param r the reference to locate the loader.
-     */
-    public void setLoaderRef(Reference r) {
-        checkAttributesAllowed();
-        loader = r;
-    }
-
-    /**
-     * Overrides the super version.
-     * @param r the Reference to set.
-     */
-    public void setRefid(Reference r) {
-        if (loader != null || classpath != null) {
-            throw tooManyAttributes();
-        }
-        super.setRefid(r);
-    }
-
-    /**
-     * Learn whether this file exists.
-     * @return true if this resource exists.
-     */
-    public boolean isExists() {
-        if (isReference()) {
-            return  ((Resource) getCheckedRef()).isExists();
-        }
-        InputStream is = null;
-        try {
-            is = getInputStream();
-            return is != null;
-        } catch (IOException ex) {
-            return false;
-        } finally {
-            FileUtils.close(is);
-        }
-    }
-
-    /**
-     * Return an InputStream for reading the contents of this Resource.
-     * @return an InputStream object.
+     * open the inpout stream from a specific classloader
+     * @param cl the classloader to use. Will be null if the system classloader is used
+     * @return an open input stream for the resource
      * @throws IOException if an error occurs.
      */
-    public InputStream getInputStream() throws IOException {
-        if (isReference()) {
-            return ((Resource) getCheckedRef()).getInputStream();
-        }
-        ClassLoader cl = null;
-        if (loader != null) {
-            cl = (ClassLoader) loader.getReferencedObject();
-        }
-        if (cl == null) {
-            if (getClasspath() != null) {
-                cl = getProject().createClassLoader(classpath);
-            } else {
-                cl = JavaResource.class.getClassLoader();
-            }
-            if (loader != null && cl != null) {
-                getProject().addReference(loader.getRefId(), cl);
-            }
-        }
-
+    protected InputStream openInputStream(ClassLoader cl) throws IOException {
         return cl == null ? ClassLoader.getSystemResourceAsStream(getName())
             : cl.getResourceAsStream(getName());
     }