Initial cleanup of JRuby extension

* Recommended changes from IntelliJ, including generic type
  cleanups, inner classes to lambdas, unused methods deprecated,
  redundant code eliminated, loops simplified, imports cleaned up,
  and more.
* Added TODOs to calls to JRuby methods deprecated in 10. These
  have replacements in 10 that will be backported after release.
  These calls should not be updated to the new versions for at
  least a year after they are available in JRuby 9.4 releases.

This commit should not contain any behavioral changes. All changes
here should be simple cleanup and Java style updates.

Author: headius

ext/java/nokogiri/Html4Document.java

@@ -52,7 +52,7 @@ public class Html4Document extends XmlDocument
     super(ruby, klazz, doc);
   }
 
-  @JRubyMethod(name = "new", meta = true, rest = true, required = 0)
+  @JRubyMethod(name = "new", meta = true, rest = true)
   public static IRubyObject
   rbNew(ThreadContext context, IRubyObject klazz, IRubyObject[] args)
   {

ext/java/nokogiri/Html4ElementDescription.java

@@ -33,7 +33,7 @@ public class Html4ElementDescription extends RubyObject
   static
   {
     Map<Short, List<String>> _subElements =
-      new HashMap<Short, List<String>>();
+      new HashMap<>();
     subElements = Collections.synchronizedMap(_subElements);
   }
 
@@ -56,7 +56,7 @@ public class Html4ElementDescription extends RubyObject
     List<String> subs = subElements.get(elem.code);
 
     if (subs == null) {
-      subs = new ArrayList<String>();
+      subs = new ArrayList<>();
 
       /*
        * A bit of a hack.  NekoHtml source code shows that
@@ -127,6 +127,7 @@ public class Html4ElementDescription extends RubyObject
       ary[i] = ruby.newString(subs.get(i));
     }
 
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     return ruby.newArray(ary);
   }
 

ext/java/nokogiri/Html4EntityLookup.java

@@ -29,7 +29,7 @@ public class Html4EntityLookup extends RubyObject
 
   /**
    * Looks up an HTML entity <code>key</code>.
-   *
+   * <p>
    * The description is a bit lacking.
    */
   @JRubyMethod()
@@ -53,11 +53,10 @@ public class Html4EntityLookup extends RubyObject
 
     IRubyObject edClass =
       ruby.getClassFromPath("Nokogiri::HTML4::EntityDescription");
-    IRubyObject edObj = invoke(context, edClass, "new",
+
+    return invoke(context, edClass, "new",
                                ruby.newFixnum(val), ruby.newString(name),
                                ruby.newString(name + " entity"));
-
-    return edObj;
   }
 
 }

ext/java/nokogiri/Html4SaxParserContext.java

@@ -1,23 +1,19 @@
 package nokogiri;
 
-import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 
 import org.apache.xerces.parsers.AbstractSAXParser;
 import net.sourceforge.htmlunit.cyberneko.parsers.SAXParser;
 import org.jruby.Ruby;
 import org.jruby.RubyClass;
 import org.jruby.RubyEncoding;
-import org.jruby.RubyFixnum;
-import org.jruby.RubyString;
 import org.jruby.anno.JRubyClass;
 import org.jruby.anno.JRubyMethod;
 import org.jruby.runtime.ThreadContext;
 import org.jruby.runtime.builtin.IRubyObject;
 import org.xml.sax.SAXException;
 
 import nokogiri.internals.NokogiriHandler;
-import static nokogiri.internals.NokogiriHelpers.rubyStringToString;
 
 import static org.jruby.runtime.Helpers.invoke;
 
@@ -65,7 +61,7 @@ public class Html4SaxParserContext extends XmlSaxParserContext
       return parser;
     } catch (SAXException ex) {
       throw new SAXException(
-        "Problem while creating HTML4 SAX Parser: " + ex.toString());
+        "Problem while creating HTML4 SAX Parser: " + ex);
     }
   }
 
@@ -76,9 +72,10 @@ public class Html4SaxParserContext extends XmlSaxParserContext
     String java_encoding = null;
     if (encoding != context.runtime.getNil()) {
       if (!(encoding instanceof RubyEncoding)) {
+        // TODO: switch to common undeprecated API when 9.4 adds 10 methods
         throw context.runtime.newTypeError("encoding must be kind_of Encoding");
       }
-      java_encoding = ((RubyEncoding)encoding).toString();
+      java_encoding = encoding.toString();
     }
 
     Html4SaxParserContext ctx = Html4SaxParserContext.newInstance(context.runtime, (RubyClass) klazz);
@@ -98,9 +95,10 @@ public class Html4SaxParserContext extends XmlSaxParserContext
     String java_encoding = null;
     if (encoding != context.runtime.getNil()) {
       if (!(encoding instanceof RubyEncoding)) {
+        // TODO: switch to common undeprecated API when 9.4 adds 10 methods
         throw context.runtime.newTypeError("encoding must be kind_of Encoding");
       }
-      java_encoding = ((RubyEncoding)encoding).toString();
+      java_encoding = encoding.toString();
     }
 
     Html4SaxParserContext ctx = Html4SaxParserContext.newInstance(context.runtime, (RubyClass) klass);
@@ -118,15 +116,17 @@ public class Html4SaxParserContext extends XmlSaxParserContext
   parse_io(ThreadContext context, IRubyObject klazz, IRubyObject data, IRubyObject encoding)
   {
     if (!invoke(context, data, "respond_to?", context.runtime.newSymbol("read")).isTrue()) {
+      // TODO: switch to common undeprecated API when 9.4 adds 10 methods
       throw context.runtime.newTypeError("argument expected to respond to :read");
     }
 
     String java_encoding = null;
     if (encoding != context.runtime.getNil()) {
       if (!(encoding instanceof RubyEncoding)) {
+        // TODO: switch to common undeprecated API when 9.4 adds 10 methods
         throw context.runtime.newTypeError("encoding must be kind_of Encoding");
       }
-      java_encoding = ((RubyEncoding)encoding).toString();
+      java_encoding = encoding.toString();
     }
 
     Html4SaxParserContext ctx = Html4SaxParserContext.newInstance(context.runtime, (RubyClass) klazz);

ext/java/nokogiri/Html4SaxPushParser.java

@@ -24,7 +24,6 @@
 /**
  * Class for Nokogiri::HTML4::SAX::PushParser
  *
- * @author
  * @author Piotr Szmielew <p.szmielew@ava.waw.pl> - based on Nokogiri::XML::SAX::PushParser
  */
 @JRubyClass(name = "Nokogiri::HTML4::SAX::PushParser")
@@ -93,6 +92,7 @@ public class Html4SaxPushParser extends RubyObject
   setOptions(ThreadContext context, IRubyObject opts)
   {
     invoke(context, parse_options(context), "options=", opts);
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     options = new ParserContext.Options(opts.convertToInteger().getLongValue());
     return getOptions(context);
   }
@@ -148,14 +148,11 @@ public class Html4SaxPushParser extends RubyObject
       assert saxParser != null : "saxParser null";
       parserTask = new ParserTask(context, saxParser, stream);
       futureTask = new FutureTask<Html4SaxParserContext>((Callable) parserTask);
-      executor = Executors.newSingleThreadExecutor(new ThreadFactory() {
-        @Override
-        public Thread newThread(Runnable r) {
-          Thread t = new Thread(r);
-          t.setName("Html4SaxPushParser");
-          t.setDaemon(true);
-          return t;
-        }
+      executor = Executors.newSingleThreadExecutor(r -> {
+        Thread t = new Thread(r);
+        t.setName("Html4SaxPushParser");
+        t.setDaemon(true);
+        return t;
       });
       executor.submit(futureTask);
     }
@@ -168,8 +165,6 @@ public Thread newThread(Runnable r) {
 
     try {
       terminateImpl();
-    } catch (InterruptedException e) {
-      throw runtime.newRuntimeError(e.toString());
     } catch (Exception e) {
       throw runtime.newRuntimeError(e.toString());
     }

ext/java/nokogiri/NokogiriService.java

@@ -5,7 +5,6 @@
 import java.util.Map;
 
 import org.jruby.Ruby;
-import org.jruby.RubyArray;
 import org.jruby.RubyClass;
 import org.jruby.RubyFixnum;
 import org.jruby.RubyModule;
@@ -33,13 +32,14 @@ public class NokogiriService implements BasicLibraryService
   public static Map<String, RubyClass>
   getNokogiriClassCache(Ruby ruby)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     return (Map<String, RubyClass>) ruby.getModule("Nokogiri").getInternalVariable("cache");
   }
 
   private static Map<String, RubyClass>
   populateNokogiriClassCache(Ruby ruby)
   {
-    Map<String, RubyClass> nokogiriClassCache = new HashMap<String, RubyClass>();
+    Map<String, RubyClass> nokogiriClassCache = new HashMap<>();
     nokogiriClassCache.put("Nokogiri::HTML4::Document", (RubyClass)ruby.getClassFromPath("Nokogiri::HTML4::Document"));
     nokogiriClassCache.put("Nokogiri::HTML4::ElementDescription",
                            (RubyClass)ruby.getClassFromPath("Nokogiri::HTML4::ElementDescription"));
@@ -78,6 +78,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   init(Ruby ruby)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyModule nokogiri = ruby.defineModule("Nokogiri");
     RubyModule xmlModule = nokogiri.defineModuleUnder("XML");
     RubyModule xmlSaxModule = xmlModule.defineModuleUnder("SAX");
@@ -97,6 +98,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   createSyntaxErrors(Ruby ruby, RubyModule nokogiri, RubyModule xmlModule)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass syntaxError = nokogiri.defineClassUnder("SyntaxError", ruby.getStandardError(),
                             ruby.getStandardError().getAllocator());
     RubyClass xmlSyntaxError = xmlModule.defineClassUnder("SyntaxError", syntaxError, XML_SYNTAXERROR_ALLOCATOR);
@@ -106,6 +108,7 @@ public class NokogiriService implements BasicLibraryService
   private RubyClass
   createXmlModule(Ruby ruby, RubyModule xmlModule)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass node = xmlModule.defineClassUnder("Node", ruby.getObject(), XML_NODE_ALLOCATOR);
     node.defineAnnotatedMethods(XmlNode.class);
 
@@ -183,6 +186,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   createHtmlModule(Ruby ruby, RubyModule htmlModule)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass htmlElemDesc = htmlModule.defineClassUnder("ElementDescription", ruby.getObject(),
                              HTML_ELEMENT_DESCRIPTION_ALLOCATOR);
     htmlElemDesc.defineAnnotatedMethods(Html4ElementDescription.class);
@@ -195,6 +199,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   createDocuments(Ruby ruby, RubyModule xmlModule, RubyModule htmlModule, RubyClass node)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass xmlDocument = xmlModule.defineClassUnder("Document", node, XML_DOCUMENT_ALLOCATOR);
     xmlDocument.defineAnnotatedMethods(XmlDocument.class);
 
@@ -206,6 +211,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   createSaxModule(Ruby ruby, RubyModule xmlSaxModule, RubyModule htmlSaxModule)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass xmlSaxParserContext = xmlSaxModule.defineClassUnder("ParserContext", ruby.getObject(),
                                     XML_SAXPARSER_CONTEXT_ALLOCATOR);
     xmlSaxParserContext.defineAnnotatedMethods(XmlSaxParserContext.class);
@@ -225,6 +231,7 @@ public class NokogiriService implements BasicLibraryService
   private void
   createXsltModule(Ruby ruby, RubyModule xsltModule)
   {
+    // TODO: switch to common undeprecated API when 9.4 adds 10 methods
     RubyClass stylesheet = xsltModule.defineClassUnder("Stylesheet", ruby.getObject(), XSLT_STYLESHEET_ALLOCATOR);
     stylesheet.defineAnnotatedMethods(XsltStylesheet.class);
   }
@@ -259,21 +266,9 @@ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
     }
   };
 
-  private static ObjectAllocator HTML_ELEMENT_DESCRIPTION_ALLOCATOR =
-    new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new Html4ElementDescription(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator HTML_ELEMENT_DESCRIPTION_ALLOCATOR = Html4ElementDescription::new;
 
-  private static ObjectAllocator HTML_ENTITY_LOOKUP_ALLOCATOR =
-    new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new Html4EntityLookup(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator HTML_ENTITY_LOOKUP_ALLOCATOR = Html4EntityLookup::new;
 
   public static final ObjectAllocator XML_ATTR_ALLOCATOR = new ObjectAllocator()
   {
@@ -486,25 +481,12 @@ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
     }
   };
 
-  private static ObjectAllocator XML_ATTRIBUTE_DECL_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new XmlAttributeDecl(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator XML_ATTRIBUTE_DECL_ALLOCATOR = XmlAttributeDecl::new;
 
-  private static ObjectAllocator XML_ENTITY_DECL_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new XmlEntityDecl(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator XML_ENTITY_DECL_ALLOCATOR = XmlEntityDecl::new;
 
-  private static ObjectAllocator XML_ELEMENT_CONTENT_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      throw runtime.newNotImplementedError("not implemented");
-    }
+  private static final ObjectAllocator XML_ELEMENT_CONTENT_ALLOCATOR = (runtime, klazz) -> {
+    throw runtime.newNotImplementedError("not implemented");
   };
 
   public static final ObjectAllocator XML_RELAXNG_ALLOCATOR = new ObjectAllocator()
@@ -537,19 +519,9 @@ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
     }
   };
 
-  private static final ObjectAllocator XML_SAXPUSHPARSER_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new XmlSaxPushParser(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator XML_SAXPUSHPARSER_ALLOCATOR = XmlSaxPushParser::new;
 
-  private static final ObjectAllocator HTML_SAXPUSHPARSER_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new Html4SaxPushParser(runtime, klazz);
-    }
-  };
+  private static final ObjectAllocator HTML_SAXPUSHPARSER_ALLOCATOR = Html4SaxPushParser::new;
 
   public static final ObjectAllocator XML_SCHEMA_ALLOCATOR = new ObjectAllocator()
   {
@@ -566,12 +538,7 @@ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
     }
   };
 
-  public static final ObjectAllocator XML_SYNTAXERROR_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new XmlSyntaxError(runtime, klazz);
-    }
-  };
+  public static final ObjectAllocator XML_SYNTAXERROR_ALLOCATOR = XmlSyntaxError::new;
 
   public static final ObjectAllocator XML_TEXT_ALLOCATOR = new ObjectAllocator()
   {
@@ -588,12 +555,7 @@ public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
     }
   };
 
-  public static final ObjectAllocator XML_XPATHCONTEXT_ALLOCATOR = new ObjectAllocator()
-  {
-    public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
-      return new XmlXpathContext(runtime, klazz);
-    }
-  };
+  public static final ObjectAllocator XML_XPATHCONTEXT_ALLOCATOR = XmlXpathContext::new;
 
   public static ObjectAllocator XSLT_STYLESHEET_ALLOCATOR = new ObjectAllocator()
   {

ext/java/nokogiri/XmlAttr.java

@@ -27,6 +27,8 @@ public class XmlAttr extends XmlNode
 {
   private static final long serialVersionUID = 1L;
 
+  // unused
+  @Deprecated
   public static final String[] HTML_BOOLEAN_ATTRS = {
     "checked", "compact", "declare", "defer", "disabled", "ismap",
     "multiple", "nohref", "noresize", "noshade", "nowrap", "readonly",
@@ -45,6 +47,8 @@ public class XmlAttr extends XmlNode
     super(ruby, rubyClass);
   }
 
+  // unused
+  @Deprecated
   public
   XmlAttr(Ruby ruby, RubyClass rubyClass, Node attr)
   {
@@ -56,6 +60,7 @@ public class XmlAttr extends XmlNode
   init(ThreadContext context, IRubyObject[] args)
   {
     if (args.length < 2) {
+      // TODO: switch to common undeprecated API when 9.4 adds 10 methods
       throw context.runtime.newArgumentError(args.length, 2);
     }