add lots of nullability annotations

(I must admit that I am not 100% all of them are correct)

doc/guide/users-guide-r7.xil

@@ -449,10 +449,9 @@ String address = "http://www.w3.org/";
 
 // render    
 try {       
-  BufferedImage buff = null;
-  buff = Graphics2DRenderer.renderToImage(address, "w3c-homepage.png", 1024);            
+  BufferedImage buff = Graphics2DRenderer.renderToImage(address, "w3c-homepage.png", 1024);            
 } catch (IOException e) {
-  e.printStackTrace();   
+  throw new RuntimeException(e);
 }
 }}
 

doc/guide/users-guide-r8.xil

@@ -450,10 +450,9 @@ String address = "http://www.w3.org/";
 
 // render    
 try {       
-  BufferedImage buff = null;
-  buff = Graphics2DRenderer.renderToImage(address, "w3c-homepage.png", 1024);            
+  BufferedImage buff = Graphics2DRenderer.renderToImage(address, "w3c-homepage.png", 1024);            
 } catch (IOException e) {
-  e.printStackTrace();   
+  throw new RuntimeException(e);
 }
 }}
 

flying-saucer-core/src/main/java/org/xhtmlrenderer/context/StylesheetFactoryImpl.java

@@ -27,6 +27,7 @@
 import org.xhtmlrenderer.extend.UserAgentCallback;
 import org.xhtmlrenderer.resource.CSSResource;
 import org.xhtmlrenderer.util.Configuration;
+import org.xhtmlrenderer.util.IOUtil;
 import org.xhtmlrenderer.util.XRLog;
 import org.xml.sax.InputSource;
 
@@ -41,7 +42,7 @@
 
 /**
  * A Factory class for Cascading Style Sheets. Sheets are parsed using a single
- * parser instance for all sheets. Sheets are cached by URI using a LRU test,
+ * parser instance for all sheets. Sheets are cached by URI using LRU test,
  * but timestamp of file is not checked.
  *
  * @author Torbjoern Gannholm
@@ -91,11 +92,7 @@ private Stylesheet parse(StylesheetInfo info) {
             // Shouldn't happen
             throw new RuntimeException(e.getMessage(), e);
         } finally {
-            try {
-                is.close();
-            } catch (IOException e) {
-                // ignore
-            }
+            IOUtil.close(is);
         }
     }
 

flying-saucer-core/src/main/java/org/xhtmlrenderer/css/parser/MakeTokens.java

@@ -44,7 +44,6 @@ public static void main(String[] args) throws IOException {
                 tokens.add(s);
             }
         }
-        // ignore
 
         StringBuilder buf = new StringBuilder();
 

flying-saucer-core/src/main/java/org/xhtmlrenderer/event/DefaultDocumentListener.java

@@ -19,32 +19,23 @@
  */
 package org.xhtmlrenderer.event;
 
+import javax.annotation.ParametersAreNonnullByDefault;
+
 /**
  * Default, do-nothing implementation of a {@link DocumentListener}; implements all methods in {@link DocumentListener}
  * but the methods do nothing. Subclass this class and override whichever methods you need to trap.
  */
+@ParametersAreNonnullByDefault
 public class DefaultDocumentListener implements DocumentListener {
-    /**
-     * {@inheritDoc}
-     */
     public void documentStarted() {
     }
 
-    /**
-     * {@inheritDoc}
-     */
     public void documentLoaded() {
     }
 
-    /**
-     * {@inheritDoc}
-     */
     public void onLayoutException(Throwable t) {
     }
 
-    /**
-     * {@inheritDoc}
-     */
     public void onRenderException(Throwable t) {
     }
 }

flying-saucer-core/src/main/java/org/xhtmlrenderer/event/DocumentListener.java

@@ -19,12 +19,15 @@
  */
 package org.xhtmlrenderer.event;
 
+import javax.annotation.ParametersAreNonnullByDefault;
+
 /**
  * Implementations of this listener interface receive notifications about
  * various document and layout events. Events are called on the Event Dispatch Thread, and will block
  * any EDT activity until the methods return; make sure you do as little as possible in each method, or where necessary,
  * spin the task off to a separate thread.
  */
+@ParametersAreNonnullByDefault
 public interface DocumentListener {
     /**
      * Indicates document has been requested (e.g. a new document is going to be
@@ -43,24 +46,23 @@ public interface DocumentListener {
 
     /**
      * Called when document layout failed with an exception. All
-     * <code>Throwable</code> objects thrown (except for
-     * <code>ThreadDeath</code>) during layout and not otherwise handled will
-     * be provided to this method. If a <code>DocumentListener</code> has been
+     * {@code Throwable} objects thrown (except for
+     * {@code ThreadDeath}) during layout and not otherwise handled will
+     * be provided to this method. If a {@code DocumentListener} has been
      * defined an XHTML panel, the listener is entirely responsible for
      * handling the exception. No other action will be taken.
      */
     void onLayoutException(Throwable t);
 
     /**
      * Called when document render failed with an exception. All
-     * <code>Throwable</code> objects thrown (except for
-     * <code>ThreadDeath</code>) during render and not otherwise handled will
-     * be provided to this method. If a <code>DocumentListener</code> has been
+     * {@code Throwable} objects thrown (except for
+     * {@code ThreadDeath}) during render and not otherwise handled will
+     * be provided to this method. If a {@code DocumentListener} has been
      * defined an XHTML panel, the listener is entirely responsible for
      * handling the exception. No other action will be taken.
      */
     void onRenderException(Throwable t);
-
 }
 
 /*

flying-saucer-core/src/main/java/org/xhtmlrenderer/extend/UserAgentCallback.java

@@ -23,6 +23,10 @@
 import org.xhtmlrenderer.resource.ImageResource;
 import org.xhtmlrenderer.resource.XMLResource;
 
+import javax.annotation.CheckReturnValue;
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
 
 /**
  * <p>To be implemented by any user agent using the panel. "User agent" is a
@@ -47,6 +51,7 @@
  *
  * @author Torbjoern Gannholm
  */
+@ParametersAreNonnullByDefault
 public interface UserAgentCallback {
     /**
      * Retrieves the CSS at the given URI. This is a synchronous call.
@@ -76,6 +81,8 @@ public interface UserAgentCallback {
      * Retrieves a binary resource located at a given URI and returns its contents
      * as a byte array or <code>null</code> if the resource could not be loaded.
      */
+    @Nullable
+    @CheckReturnValue
     byte[] getBinaryResource(String uri);
 
     /**
@@ -85,15 +92,16 @@ public interface UserAgentCallback {
      * @param uri A URI which may have been visited by this user agent.
      * @return The visited value
      */
-    boolean isVisited(String uri);
+    @CheckReturnValue
+    boolean isVisited(@Nullable String uri);
 
     /**
      * Does not need to be a correct URL, only an identifier that the
      * implementation can resolve.
      *
      * @param url A URL against which relative references can be resolved.
      */
-    void setBaseURL(String url);
+    void setBaseURL(@Nullable String url);
 
     /**
      * @return the base uri, possibly in the implementations private uri-space
@@ -108,6 +116,8 @@ public interface UserAgentCallback {
      * @param uri an absolute or relative (to baseURL) uri to be resolved.
      * @return the full uri in uri-spaces known to the current implementation.
      */
-    String resolveURI(String uri);
+    @Nullable
+    @CheckReturnValue
+    String resolveURI(@Nullable String uri);
 }
 

flying-saucer-core/src/main/java/org/xhtmlrenderer/layout/SharedContext.java

@@ -46,6 +46,7 @@
 import org.xhtmlrenderer.swing.SwingReplacedElementFactory;
 import org.xhtmlrenderer.util.XRLog;
 
+import javax.annotation.Nullable;
 import java.awt.*;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -370,7 +371,7 @@ public String getBaseURL() {
      *
      * @param url The new baseURL value
      */
-    public void setBaseURL(String url) {
+    public void setBaseURL(@Nullable String url) {
         uac.setBaseURL(url);
     }
 

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/AbstractResource.java

@@ -21,46 +21,46 @@
 
 import org.xml.sax.InputSource;
 
+import javax.annotation.CheckReturnValue;
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
 import java.io.BufferedInputStream;
 import java.io.InputStream;
 
 /**
  * @author Patrick Wright
  */
+@ParametersAreNonnullByDefault
 public abstract class AbstractResource implements Resource {
-    private InputSource inputSource;
+    private final InputSource inputSource;
     private final long createTimeStamp;
     private long elapsedLoadTime;
 
-    private AbstractResource() {
-        this.createTimeStamp = System.currentTimeMillis();
-    }
-
-    /**
-     * Creates a new instance of AbstractResource
-     */
-    public AbstractResource(InputSource source) {
-        this();
+    protected AbstractResource(@Nullable InputSource source) {
         this.inputSource = source;
+        this.createTimeStamp = System.currentTimeMillis();
     }
 
-    public AbstractResource(InputStream is) {
+    protected AbstractResource(@Nullable InputStream is) {
         this(is == null ? null : new InputSource(new BufferedInputStream(is)));
     }
 
+    @Nullable
+    @CheckReturnValue
     public InputSource getResourceInputSource() {
         return this.inputSource;
     }
 
+    @CheckReturnValue
     public long getResourceLoadTimeStamp() {
         return this.createTimeStamp;
     }
 
+    @CheckReturnValue
     public long getElapsedLoadTime() {
         return elapsedLoadTime;
     }
 
-    /*package*/
     void setElapsedLoadTime(long elapsedLoadTime) {
         this.elapsedLoadTime = elapsedLoadTime;
     }

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/CSSResource.java

@@ -19,20 +19,18 @@
  */
 package org.xhtmlrenderer.resource;
 
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
 import java.io.InputStream;
 
 /**
  * @author Administrator
  */
+@ParametersAreNonnullByDefault
 public class CSSResource extends AbstractResource {
-
-    /**
-     * Creates a new instance of CSSResource
-     */
-    public CSSResource(InputStream stream) {
+    public CSSResource(@Nullable InputStream stream) {
         super(stream);
     }
-
 }
 
 /*

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/ImageResource.java

@@ -24,15 +24,19 @@
 import org.xhtmlrenderer.swing.MutableFSImage;
 import org.xml.sax.InputSource;
 
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
 /**
  * @author Administrator
  */
+@ParametersAreNonnullByDefault
 public class ImageResource extends AbstractResource {
     private final String _imageUri;
     private final FSImage _img;
 
     //HACK: at least for now, till we know what we want to do here
-    public ImageResource(final String uri, FSImage img) {
+    public ImageResource(@Nullable final String uri, @Nullable FSImage img) {
         super((InputSource) null);
         _imageUri = uri;
         _img = img;

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/Resource.java

@@ -21,21 +21,20 @@
 
 import org.xml.sax.InputSource;
 
+import javax.annotation.CheckReturnValue;
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
 /**
  *
  * @author Patrick Wright
  */
+@ParametersAreNonnullByDefault
 public interface Resource {
+    @Nullable
+    @CheckReturnValue
     InputSource getResourceInputSource();
-    long getResourceLoadTimeStamp();
-}
 
-/*
- * $Id$
- *
- * $Log$
- * Revision 1.1  2005/02/03 20:39:35  pdoubleya
- * Added to CVS.
- *
- *
- */
+    @CheckReturnValue
+    long getResourceLoadTimeStamp();
+}

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/XMLResource.java

@@ -35,6 +35,7 @@
 import org.xml.sax.helpers.XMLFilterImpl;
 import org.xml.sax.helpers.XMLReaderFactory;
 
+import javax.annotation.ParametersAreNonnullByDefault;
 import javax.xml.XMLConstants;
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
@@ -57,6 +58,7 @@
 /**
  * @author Patrick Wright
  */
+@ParametersAreNonnullByDefault
 public class XMLResource extends AbstractResource {
     private Document document;
     private static final XMLResourceBuilder XML_RESOURCE_BUILDER;