Fix for JRUBY-2882. Handle error messages related to constructors better

[jruby.git] / src / org / jruby / javasupport / JavaMethod.java

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 * Copyright (C) 2001 Chad Fowler <chadfowler@chadfowler.com>
 * Copyright (C) 2001 Alan Moore <alan_moore@gmx.net>
 * Copyright (C) 2001-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004 David Corbin <dcorbin@users.sourceforge.net>
 * Copyright (C) 2005 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2006 Kresten Krab Thorup <krab@gnu.org>
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package org.jruby.javasupport;

import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;

import org.jruby.Ruby;
import org.jruby.RubyBoolean;
import org.jruby.RubyClass;
import org.jruby.RubyModule;
import org.jruby.RubyString;
import org.jruby.anno.JRubyClass;
import org.jruby.anno.JRubyMethod;
import org.jruby.javasupport.proxy.InternalJavaProxy;
import org.jruby.javasupport.proxy.JavaProxyClass;
import org.jruby.javasupport.proxy.JavaProxyMethod;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.builtin.IRubyObject;

@JRubyClass(name="Java::JavaMethod")
public class JavaMethod extends JavaCallable {
    private final Method method;
    private final Class<?>[] parameterTypes;
    private final JavaUtil.JavaConverter returnConverter;

    public static RubyClass createJavaMethodClass(Ruby runtime, RubyModule javaModule) {
        // TODO: NOT_ALLOCATABLE_ALLOCATOR is probably ok here, since we don't intend for people to monkey with
        // this type and it can't be marshalled. Confirm. JRUBY-415
        RubyClass result = 
            javaModule.defineClassUnder("JavaMethod", runtime.getObject(), ObjectAllocator.NOT_ALLOCATABLE_ALLOCATOR);

        JavaAccessibleObject.registerRubyMethods(runtime, result);
        JavaCallable.registerRubyMethods(runtime, result);
        
        result.defineAnnotatedMethods(JavaMethod.class);

        return result;
    }

    public JavaMethod(Ruby runtime, Method method) {
        super(runtime, runtime.getJavaSupport().getJavaMethodClass());
        this.method = method;
        this.parameterTypes = method.getParameterTypes();

        // Special classes like Collections.EMPTY_LIST are inner classes that are private but 
        // implement public interfaces.  Their methods are all public methods for the public 
        // interface.  Let these public methods execute via setAccessible(true). 
        if (Modifier.isPublic(method.getModifiers()) &&
            Modifier.isPublic(method.getClass().getModifiers()) &&
            !Modifier.isPublic(method.getDeclaringClass().getModifiers())) {
            accessibleObject().setAccessible(true);
        }
        
        returnConverter = JavaUtil.getJavaConverter(method.getReturnType());
    }

    public static JavaMethod create(Ruby runtime, Method method) {
        return new JavaMethod(runtime, method);
    }

    public static JavaMethod create(Ruby runtime, Class<?> javaClass, String methodName, Class<?>[] argumentTypes) {
        try {
            Method method = javaClass.getMethod(methodName, argumentTypes);
            return create(runtime, method);
        } catch (NoSuchMethodException e) {
            throw runtime.newNameError("undefined method '" + methodName + "' for class '" + javaClass.getName() + "'",
                    methodName);
        }
    }

    public static JavaMethod createDeclared(Ruby runtime, Class<?> javaClass, String methodName, Class<?>[] argumentTypes) {
        try {
            return create(runtime, javaClass.getDeclaredMethod(methodName, argumentTypes));
        } catch (NoSuchMethodException e) {
            throw runtime.newNameError("undefined method '" + methodName + "' for class '" + javaClass.getName() + "'",
                    methodName);
        }
    }

    public static JavaMethod getMatchingDeclaredMethod(Ruby runtime, Class<?> javaClass, String methodName, Class<?>[] argumentTypes) {
        // FIXME: do we really want 'declared' methods?  includes private/protected, and does _not_
        // include superclass methods.  also, the getDeclared calls may throw SecurityException if
        // we're running under a restrictive security policy.
        try {
            return create(runtime, javaClass.getDeclaredMethod(methodName, argumentTypes));
        } catch (NoSuchMethodException e) {
            // search through all declared methods to find a closest match
            MethodSearch: for (Method method : javaClass.getDeclaredMethods()) {
                if (method.getName().equals(methodName)) {
                    Class<?>[] targetTypes = method.getParameterTypes();
                
                    // for zero args case we can stop searching
                    if (targetTypes.length == 0 && argumentTypes.length == 0) {
                        return create(runtime, method);
                    }
                    
                    TypeScan: for (int i = 0; i < argumentTypes.length; i++) {
                        if (i >= targetTypes.length) continue MethodSearch;

                        if (targetTypes[i].isAssignableFrom(argumentTypes[i])) {
                            continue TypeScan;
                        } else {
                            continue MethodSearch;
                        }
                    }

                    // if we get here, we found a matching method, use it
                    // TODO: choose narrowest method by continuing to search
                    return create(runtime, method);
                }
            }
        }
        // no matching method found
        return null;
    }
    
    public boolean equals(Object other) {
        return other instanceof JavaMethod &&
            this.method == ((JavaMethod)other).method;
    }
    
    public int hashCode() {
        return method.hashCode();
    }

    @JRubyMethod
    public RubyString name() {
        return getRuntime().newString(method.getName());
    }

    public int getArity() {
        return parameterTypes.length;
    }

    @JRubyMethod(name = "public?")
    public RubyBoolean public_p() {
        return getRuntime().newBoolean(Modifier.isPublic(method.getModifiers()));
    }

    @JRubyMethod(name = "final?")
    public RubyBoolean final_p() {
        return getRuntime().newBoolean(Modifier.isFinal(method.getModifiers()));
    }

    @JRubyMethod(rest = true)
    public IRubyObject invoke(IRubyObject[] args) {
        if (args.length != 1 + getArity()) {
            throw getRuntime().newArgumentError(args.length, 1 + getArity());
        }

        Object[] arguments = new Object[args.length - 1];
        convertArguments(getRuntime(), arguments, args, 1);

        IRubyObject invokee = args[0];
        if(invokee.isNil()) {
            return invokeWithExceptionHandling(method, null, arguments);
        }

        Object javaInvokee = JavaUtil.unwrapJavaObject(getRuntime(), invokee, "invokee not a java object").getValue();

        if (! method.getDeclaringClass().isInstance(javaInvokee)) {
            throw getRuntime().newTypeError("invokee not instance of method's class (" +
                                              "got" + javaInvokee.getClass().getName() + " wanted " +
                                              method.getDeclaringClass().getName() + ")");
        }
        
        //
        // this test really means, that this is a ruby-defined subclass of a java class
        //
        if (javaInvokee instanceof InternalJavaProxy &&
                // don't bother to check if final method, it won't
                // be there (not generated, can't be!)
                !Modifier.isFinal(method.getModifiers())) {
            JavaProxyClass jpc = ((InternalJavaProxy) javaInvokee)
                    .___getProxyClass();
            JavaProxyMethod jpm;
            if ((jpm = jpc.getMethod(method.getName(), parameterTypes)) != null &&
                    jpm.hasSuperImplementation()) {
                return invokeWithExceptionHandling(jpm.getSuperMethod(), javaInvokee, arguments);
            }
        }
        return invokeWithExceptionHandling(method, javaInvokee, arguments);
    }

    public IRubyObject invoke(IRubyObject self, Object[] args) {
        if (args.length != getArity()) {
            throw getRuntime().newArgumentError(args.length, getArity());
        }

        if (! (self instanceof JavaObject)) {
            throw getRuntime().newTypeError("invokee not a java object");
        }
        Object javaInvokee = ((JavaObject) self).getValue();

        if (! method.getDeclaringClass().isInstance(javaInvokee)) {
            throw getRuntime().newTypeError("invokee not instance of method's class (" +
                                              "got" + javaInvokee.getClass().getName() + " wanted " +
                                              method.getDeclaringClass().getName() + ")");
        }
        
        //
        // this test really means, that this is a ruby-defined subclass of a java class
        //
        if (javaInvokee instanceof InternalJavaProxy &&
                // don't bother to check if final method, it won't
                // be there (not generated, can't be!)
                !Modifier.isFinal(method.getModifiers())) {
            JavaProxyClass jpc = ((InternalJavaProxy) javaInvokee)
                    .___getProxyClass();
            JavaProxyMethod jpm;
            if ((jpm = jpc.getMethod(method.getName(), parameterTypes)) != null &&
                    jpm.hasSuperImplementation()) {
                return invokeWithExceptionHandling(jpm.getSuperMethod(), javaInvokee, args);
            }
        }
        return invokeWithExceptionHandling(method, javaInvokee, args);
    }

    @JRubyMethod(rest = true)
    public IRubyObject invoke_static(IRubyObject[] args) {
        if (args.length != getArity()) {
            throw getRuntime().newArgumentError(args.length, getArity());
        }
        Object[] arguments = new Object[args.length];
        System.arraycopy(args, 0, arguments, 0, arguments.length);
        convertArguments(getRuntime(), arguments, args, 0);
        return invokeWithExceptionHandling(method, null, arguments);
    }

    public IRubyObject invoke_static(Object[] args) {
        if (args.length != getArity()) {
            throw getRuntime().newArgumentError(args.length, getArity());
        }
        
        return invokeWithExceptionHandling(method, null, args);
    }

    @JRubyMethod
    public IRubyObject return_type() {
        Class<?> klass = method.getReturnType();
        
        if (klass.equals(void.class)) {
            return getRuntime().getNil();
        }
        return JavaClass.get(getRuntime(), klass);
    }

    @JRubyMethod
    public IRubyObject type_parameters() {
        return Java.getInstance(getRuntime(), method.getTypeParameters());
    }

    private IRubyObject invokeWithExceptionHandling(Method method, Object javaInvokee, Object[] arguments) {
        try {
            Object result = method.invoke(javaInvokee, arguments);
            return returnConverter.convert(getRuntime(), result);
        } catch (IllegalArgumentException iae) {
            throw getRuntime().newTypeError("for method " + method.getName() + " expected " + argument_types().inspect() + "; got: "
                        + dumpArgTypes(arguments)
                        + "; error: " + iae.getMessage());
        } catch (IllegalAccessException iae) {
            throw getRuntime().newTypeError("illegal access on '" + method.getName() + "': " + iae.getMessage());
        } catch (InvocationTargetException ite) {
            getRuntime().getJavaSupport().handleNativeException(ite.getTargetException());
            // This point is only reached if there was an exception handler installed.
            return getRuntime().getNil();
        }
    }

    private String dumpArgTypes(Object[] arguments) {
        StringBuilder str = new StringBuilder("[");
        for (int i = 0; i < arguments.length; i++) {
            if (i > 0) {
                str.append(",");
            }
            if (arguments[i] == null) {
                str.append("null");
            } else {
                str.append(arguments[i].getClass().getName());
            }
        }
        str.append("]");
        return str.toString();
    }

    private void convertArguments(Ruby runtime, Object[] arguments, Object[] args, int from) {
        Class<?>[] types = parameterTypes;
        for (int i = arguments.length; --i >= 0; ) {
            arguments[i] = JavaUtil.convertArgument(runtime, args[i+from], types[i]);
        }
    }

    public Class<?>[] getParameterTypes() {
        return parameterTypes;
    }

    public Class<?>[] getExceptionTypes() {
        return method.getExceptionTypes();
    }

    public Type[] getGenericParameterTypes() {
        return method.getGenericParameterTypes();
    }

    public Type[] getGenericExceptionTypes() {
        return method.getGenericExceptionTypes();
    }
    
    public Annotation[][] getParameterAnnotations() {
        return method.getParameterAnnotations();
    }

    public boolean isVarArgs() {
        return method.isVarArgs();
    }

    protected String nameOnInspection() {
        return "#<" + getType().toString() + "/" + method.getName() + "(";
    }

    public RubyBoolean static_p() {
        return getRuntime().newBoolean(isStatic());
    }
    
    public RubyBoolean bridge_p() {
        return getRuntime().newBoolean(method.isBridge());
    }

    private boolean isStatic() {
        return Modifier.isStatic(method.getModifiers());
    }

    public int getModifiers() {
        return method.getModifiers();
    }

    public String toGenericString() {
        return method.toGenericString();
    }

    protected AccessibleObject accessibleObject() {
        return method;
    }
}