attempt to fix breakage in Java 6 where AutoCloseable is not available without resorting to reflection or loading classes by name

Author: mikesamuel

.travis.yml

@@ -1,4 +1,7 @@
 language: java
+sudo: false
 jdk:
   - openjdk6
-  - oraclejdk7
+  - oraclejdk7
+  - oraclejdk8
+  - oraclejdk9

pom.xml

@@ -53,6 +53,24 @@ application while protecting against XSS.
 
   <build>
     <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>build-helper-maven-plugin</artifactId>
+        <version>1.10</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>
       <plugin>
         <groupId>external.atlassian.jgitflow</groupId>
         <artifactId>jgitflow-maven-plugin</artifactId>
@@ -238,14 +256,14 @@ application while protecting against XSS.
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>[3.8.1,)</version>
+      <version>4.12</version>
       <scope>test</scope>
     </dependency>
 
     <dependency>
       <groupId>nu.validator.htmlparser</groupId>
       <artifactId>htmlparser</artifactId>
-      <version>[1.2.1,)</version>
+      <version>1.4</version>
       <scope>test</scope>
     </dependency>
   </dependencies>

src/main/java-1.6/org/owasp/html/AutoCloseableHtmlStreamRenderer.java

@@ -0,0 +1,25 @@
+package org.owasp.html;
+
+import java.io.IOException;
+import javax.annotation.WillCloseWhenClosed;
+
+final class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer {
+
+  static boolean isAutoCloseable(Object o) {
+    return false;
+  }
+
+  static AutoCloseableHtmlStreamRenderer createAutoCloseableHtmlStreamRenderer(
+      @WillCloseWhenClosed
+      Appendable output, Handler<? super IOException> errorHandler,
+      Handler<? super String> badHtmlHandler) {
+    throw new UnsupportedOperationException();
+  }
+
+  AutoCloseableHtmlStreamRenderer(
+      @WillCloseWhenClosed
+      Appendable output, Handler<? super IOException> errorHandler,
+      Handler<? super String> badHtmlHandler) {
+    super(output, errorHandler, badHtmlHandler);
+  }
+}

src/main/java-1.7/org/owasp/html/AutoCloseableHtmlStreamRenderer.java

@@ -0,0 +1,34 @@
+package org.owasp.html;
+
+import java.io.IOException;
+import javax.annotation.WillCloseWhenClosed;
+
+final class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer
+  implements AutoCloseable {
+  private final AutoCloseable closeable;
+
+  static boolean isAutoCloseable(Object o) {
+    return o instanceof AutoCloseable;
+  }
+
+  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 = (AutoCloseable) output;
+  }
+
+  public void close() throws Exception {
+    if (isDocumentOpen()) { closeDocument(); }
+    closeable.close();
+  }
+}

src/main/java-1.8/org/owasp/html/AutoCloseableHtmlStreamRenderer.java

@@ -0,0 +1,34 @@
+package org.owasp.html;
+
+import java.io.IOException;
+import javax.annotation.WillCloseWhenClosed;
+
+final class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer
+  implements AutoCloseable {
+  private final AutoCloseable closeable;
+
+  static boolean isAutoCloseable(Object o) {
+    return o instanceof AutoCloseable;
+  }
+
+  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 = (AutoCloseable) output;
+  }
+
+  public void close() throws Exception {
+    if (isDocumentOpen()) { closeDocument(); }
+    closeable.close();
+  }
+}

src/main/java-1.9/org/owasp/html/AutoCloseableHtmlStreamRenderer.java

@@ -0,0 +1,34 @@
+package org.owasp.html;
+
+import java.io.IOException;
+import javax.annotation.WillCloseWhenClosed;
+
+final class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer
+  implements AutoCloseable {
+  private final AutoCloseable closeable;
+
+  static boolean isAutoCloseable(Object o) {
+    return o instanceof AutoCloseable;
+  }
+
+  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 = (AutoCloseable) output;
+  }
+
+  public void close() throws Exception {
+    if (isDocumentOpen()) { closeDocument(); }
+    closeable.close();
+  }
+}

src/main/java/org/owasp/html/HtmlStreamRenderer.java

@@ -74,8 +74,8 @@ public static HtmlStreamRenderer create(
     if (output instanceof Closeable) {
       return new CloseableHtmlStreamRenderer(
           output, ioExHandler, badHtmlHandler);
-    } else if (output instanceof AutoCloseable) {
-      return new AutoCloseableHtmlStreamRenderer(
+    } else if (AutoCloseableHtmlStreamRenderer.isAutoCloseable(output)) {
+      return AutoCloseableHtmlStreamRenderer.createAutoCloseableHtmlStreamRenderer(
           output, ioExHandler, badHtmlHandler);
     } else {
       return new HtmlStreamRenderer(output, ioExHandler, badHtmlHandler);
@@ -96,7 +96,7 @@ public static HtmlStreamRenderer create(
     return create(output, Handler.PROPAGATE, badHtmlHandler);
   }
 
-  private HtmlStreamRenderer(
+  protected HtmlStreamRenderer(
       Appendable output, Handler<? super IOException> ioExHandler,
       Handler<? super String> badHtmlHandler) {
     this.output = output;
@@ -421,23 +421,4 @@ public void close() throws IOException {
       closeable.close();
     }
   }
-
-  static class AutoCloseableHtmlStreamRenderer extends HtmlStreamRenderer
-  implements AutoCloseable {
-    private final AutoCloseable closeable;
-
-    @SuppressWarnings("synthetic-access")
-    AutoCloseableHtmlStreamRenderer(
-        @WillCloseWhenClosed
-        Appendable output, Handler<? super IOException> errorHandler,
-        Handler<? super String> badHtmlHandler) {
-      super(output, errorHandler, badHtmlHandler);
-      this.closeable = (AutoCloseable) output;
-    }
-
-    public void close() throws Exception {
-      if (isDocumentOpen()) { closeDocument(); }
-      closeable.close();
-    }
-  }
 }