@RubyLevelMethod(name = "require_java", alias = "import", module = true)
public static RubyValue requireJava(RubyValue receiver, RubyValue arg, RubyBlock block) {
String className = arg.toStr();
String[] names = packagePattern.split(className);
String name = names[names.length - 1];
if (name.equals("*")) {
JavaClass.addPackage(className.substring(0, className.lastIndexOf('.')));
} else {
try {
Class clazz = Class.forName(className);
JavaClass.createJavaClass(clazz);
} catch (ClassNotFoundException e) {
throw new RubyException("Couldn't find class " + className);
}
}
RubyRuntime.setJavaSupported(true);
return RubyConstant.QTRUE;
}
public static void main(String[] args) throws Exception {
String program_text =
""
+ "import 'java.util.*'\n"
+ "r = Random.new"
+ "\n"
+
// call overloaded methods
"puts r.nextInt\n"
+ "puts r.nextInt(3)\n"
+
// call methods inherited superclass(for example:Object)
"puts r.toString\n"
+
// call static methods and fields
"require_java 'java.lang.Math'\n"
+ "puts JMath.PI\n"
+ "puts JMath.cos(0)\n"
+
// access Java constant variables
"require_java 'java.lang.System'\n"
+ "out = System::out\n"
+ "out.println('ok!')\n"
+
// escape from name collision
"require_java 'java.lang.Object'\n"
+ "o = JObject.new\n"
+ "puts o.toString\n"
+
// implement a Java interface
"require_java 'java.lang.Runnable'\n"
+ "require_java 'java.lang.Thread'\n"
+ "class MyRunnable < Runnable\n"
+ " def run\n"
+ " puts 'Thread is running!'\n"
+ " end\n"
+ "end\n"
+ "r = MyRunnable.new\n"
+ "thread = JThread.new(r)\n"
+ "thread.start()\n"
+
// Creating Java Arrays and accessing Java Arrays
"require_java 'com.xruby.runtime.javasupport.AssistantTester'\n"
+ "require_java 'java.lang.reflect.Array'\n"
+ "require_java 'java.lang.String'\n"
+ "s = JArray.newInstance(JString, 2)\n"
+ "s[0]='Hello '\n"
+ "s[1]='World!'\n"
+ "AssistantTester.echo(s)\n"
+
// Handling Java exceptions
"require_java 'java.io.FileInputStream'\n"
+ "require_java 'java.io.FileNotFoundException'\n"
+ "require_java 'java.io.IOException'\n"
+ "begin\n"
+ " f = FileInputStream.new('myfile')\n"
+ "rescue FileNotFoundException=>fnfe\n"
+ " puts fnfe.getMessage\n"
+ "rescue IOException=>ioe\n"
+ " puts ioe\n"
+ "end\n"
+ "array = ArrayList.new\n"
+ "array.add 1\n"
+ "array.add 2\n"
+ "array.add 3\n"
+ "for i in 1 ... 3\n"
+ " puts array.get(i)\n"
+ "end\n"
+
// JavaBean support
"require_java 'javax.swing.JFrame'\n"
+ "f = JFrame.new('hello')\n"
+
// calls setVisible
"f.visible= true\n"
+
// calls getTitle
"puts f.title\n"
+ "\n";
RubyCompiler compiler = new RubyCompiler();
CompilationResults codes = compiler.compileString(program_text);
RubyProgram p = codes.getRubyProgram();
RubyRuntime.init(args);
p.invoke();
RubyRuntime.fini();
}