issue 50 : AutoCloseable ClassNotFoundError on JDK6

Author: mikesamuel

pom.xml

@@ -13,25 +13,6 @@
 
   <build>
     <plugins>
-      <plugin>
-        <groupId>org.codehaus.mojo</groupId>
-        <artifactId>build-helper-maven-plugin</artifactId>
-        <version>1.1</version>
-        <executions>
-          <!-- This is a horrible hack.  We need to support AutoCloseable
-               which is @since 1.7 but also need to compile on 1.6. -->
-          <execution>
-            <phase>generate-sources</phase>
-            <goals><goal>add-source</goal></goals>
-            <configuration>
-              <sources>
-                <source>src/main/java-${java.vm.specification.version}</source>
-              </sources>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-
       <!-- http://www.javaworld.com/article/2074515/core-java/
            unit-test-code-coverage-with-maven-and-jacoco.html -->
       <plugin>

src/main/java-1.0/org/owasp/html/AutoCloseableHtmlStreamRenderer.java

@@ -0,0 +1,90 @@
+package org.owasp.html;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import javax.annotation.WillCloseWhenClosed;
+
+import com.google.common.base.Throwables;
+
+final class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer
+  // This is available on JDK6 and makes this class extend AutoCloseable.
+  implements Closeable {
+  private final Object closeable;
+
+  private static final Class<?> CLASS_AUTO_CLOSEABLE;
+
+  static {
+    Class<?> classAutoCloseable = null;
+    for (Class<?> superInterface : Closeable.class.getInterfaces()) {
+      if ("java.lang.Autocloseable".equals(superInterface.getName())) {
+        classAutoCloseable = superInterface;
+        break;
+      }
+    }
+    CLASS_AUTO_CLOSEABLE = classAutoCloseable;
+  }
+
+  private static final Method METHOD_CLOSE;
+
+  static {
+    Method methodClose = null;
+    if (CLASS_AUTO_CLOSEABLE != null) {
+      try {
+        methodClose = CLASS_AUTO_CLOSEABLE.getMethod("close");
+      } catch (NoSuchMethodException ex) {
+        throw (NoSuchMethodError) new NoSuchMethodError().initCause(ex);
+      }
+    }
+    METHOD_CLOSE = methodClose;
+  }
+
+  static boolean isAutoCloseable(Object o) {
+    return o instanceof Closeable
+        || CLASS_AUTO_CLOSEABLE != null && CLASS_AUTO_CLOSEABLE.isInstance(o);
+  }
+
+  static AutoCloseableHtmlStreamRenderer createAutoCloseableHtmlStreamRenderer(
+      @WillCloseWhenClosed
+      Appendable output, Handler<? super IOException> errorHandler,
+      Handler<? super String> badHtmlHandler) {
+    return new AutoCloseableHtmlStreamRenderer(
+        output, errorHandler, badHtmlHandler);
+  }
+
+  private AutoCloseableHtmlStreamRenderer(
+      @WillCloseWhenClosed
+      Appendable output, Handler<? super IOException> errorHandler,
+      Handler<? super String> badHtmlHandler) {
+    super(output, errorHandler, badHtmlHandler);
+    this.closeable = output;
+  }
+
+  private static final Object[] ZERO_OBJECTS = new Object[0];
+
+  public void close() throws IOException {
+    if (isDocumentOpen()) { closeDocument(); }
+    closeIfAnyCloseable(closeable);
+  }
+
+  static void closeIfAnyCloseable(Object closeable) throws IOException {
+    if (closeable instanceof Closeable) {
+      ((Closeable) closeable).close();
+    } else if (METHOD_CLOSE != null) {
+      try {
+        METHOD_CLOSE.invoke(closeable, ZERO_OBJECTS);
+      } catch (IllegalAccessException ex) {
+        throw new AssertionError("close not public", ex);
+      } catch (InvocationTargetException ex) {
+        Throwable tgt = ex.getTargetException();
+        if (tgt instanceof IOException) {
+          throw (IOException) tgt;
+        } else {
+          Throwables.propagate(tgt);
+        }
+      }
+    }
+  }
+}