functioncall.java

java1.6众多例子参考

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: FunctionCall.java,v 1.2.4.1 2005/09/12 10:31:32 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.IFEQ;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionConstants;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.InvokeInstruction;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.NEW;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.IntType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MultiHashtable;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ObjectType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 * @author Erwin Bolwidt <[e-mail]>
 * @author Todd Miller
 */
class FunctionCall extends Expression {

    // Name of this function call
    private QName  _fname;
    // Arguments to this function call (might not be any)
    private final Vector _arguments;
    // Empty argument list, used for certain functions
    private final static Vector EMPTY_ARG_LIST = new Vector(0);

    // Valid namespaces for Java function-call extension
    protected final static String EXT_XSLTC = 
	TRANSLET_URI;

    protected final static String JAVA_EXT_XSLTC = 
	EXT_XSLTC + "/java";

    protected final static String EXT_XALAN =
	"http://xml.apache.org/xalan";

    protected final static String JAVA_EXT_XALAN =
	"http://xml.apache.org/xalan/java";

    protected final static String JAVA_EXT_XALAN_OLD =
	"http://xml.apache.org/xslt/java";
	
    protected final static String EXSLT_COMMON =
	"http://exslt.org/common";

    protected final static String EXSLT_MATH =
	"http://exslt.org/math";
	
    protected final static String EXSLT_SETS =
	"http://exslt.org/sets";

    protected final static String EXSLT_DATETIME =
	"http://exslt.org/dates-and-times";

    protected final static String EXSLT_STRINGS =
	"http://exslt.org/strings";
	
    // Namespace format constants
    protected final static int NAMESPACE_FORMAT_JAVA = 0;
    protected final static int NAMESPACE_FORMAT_CLASS = 1;
    protected final static int NAMESPACE_FORMAT_PACKAGE = 2;
    protected final static int NAMESPACE_FORMAT_CLASS_OR_PACKAGE = 3;
	
    // Namespace format
    private int _namespace_format = NAMESPACE_FORMAT_JAVA;
        
    /**
     * Stores reference to object for non-static Java calls
     */
    Expression _thisArgument = null;

    // External Java function's class/method/signature
    private String      _className;
    private Class       _clazz;
    private Method      _chosenMethod;
    private Constructor _chosenConstructor;
    private MethodType  _chosenMethodType;

    // Encapsulates all unsupported external function calls
    private boolean    unresolvedExternal;

    // If FunctionCall is a external java constructor 
    private boolean     _isExtConstructor = false; 

    // If the java method is static
    private boolean 	  _isStatic = false;

    // Legal conversions between internal and Java types.
    private static final MultiHashtable _internal2Java = new MultiHashtable();

    // Legal conversions between Java and internal types.
    private static final Hashtable _java2Internal = new Hashtable();
    
    // The mappings between EXSLT extension namespaces and implementation classes
    private static final Hashtable _extensionNamespaceTable = new Hashtable();

    // Extension functions that are implemented in BasisLibrary
    private static final Hashtable _extensionFunctionTable = new Hashtable();
    /**
     * inner class to used in internal2Java mappings, contains
     * the Java type and the distance between the internal type and
     * the Java type. 
     */
    static class JavaType {
	public Class  type;
	public int distance;
	
	public JavaType(Class type, int distance){
	    this.type = type;
	    this.distance = distance;
	}
	public boolean equals(Object query){
	    return query.equals(type);
	}
    } 

    /**
     * Defines 2 conversion tables:
     * 1. From internal types to Java types and
     * 2. From Java types to internal types.
     * These two tables are used when calling external (Java) functions.
     */
    static {
	try {
	    final Class nodeClass     = Class.forName("org.w3c.dom.Node");
	    final Class nodeListClass = Class.forName("org.w3c.dom.NodeList");

	    // -- Internal to Java --------------------------------------------
            
            // Type.Boolean -> { boolean(0), Boolean(1), Object(2) }
	    _internal2Java.put(Type.Boolean, new JavaType(Boolean.TYPE, 0));
	    _internal2Java.put(Type.Boolean, new JavaType(Boolean.class, 1));
	    _internal2Java.put(Type.Boolean, new JavaType(Object.class, 2));

            // Type.Real -> { double(0), Double(1), float(2), long(3), int(4),
            //                short(5), byte(6), char(7), Object(8) }
	    _internal2Java.put(Type.Real, new JavaType(Double.TYPE, 0));
	    _internal2Java.put(Type.Real, new JavaType(Double.class, 1));
	    _internal2Java.put(Type.Real, new JavaType(Float.TYPE, 2));
	    _internal2Java.put(Type.Real, new JavaType(Long.TYPE, 3));
	    _internal2Java.put(Type.Real, new JavaType(Integer.TYPE, 4));
	    _internal2Java.put(Type.Real, new JavaType(Short.TYPE, 5));
	    _internal2Java.put(Type.Real, new JavaType(Byte.TYPE, 6));
	    _internal2Java.put(Type.Real, new JavaType(Character.TYPE, 7)); 
	    _internal2Java.put(Type.Real, new JavaType(Object.class, 8));
            
            // Type.Int must be the same as Type.Real
	    _internal2Java.put(Type.Int, new JavaType(Double.TYPE, 0));
	    _internal2Java.put(Type.Int, new JavaType(Double.class, 1));
	    _internal2Java.put(Type.Int, new JavaType(Float.TYPE, 2));
	    _internal2Java.put(Type.Int, new JavaType(Long.TYPE, 3));
	    _internal2Java.put(Type.Int, new JavaType(Integer.TYPE, 4));
	    _internal2Java.put(Type.Int, new JavaType(Short.TYPE, 5));
	    _internal2Java.put(Type.Int, new JavaType(Byte.TYPE, 6));
	    _internal2Java.put(Type.Int, new JavaType(Character.TYPE, 7)); 
	    _internal2Java.put(Type.Int, new JavaType(Object.class, 8));
            
            // Type.String -> { String(0), Object(1) }
	    _internal2Java.put(Type.String, new JavaType(String.class, 0)); 
	    _internal2Java.put(Type.String, new JavaType(Object.class, 1));

            // Type.NodeSet -> { NodeList(0), Node(1), Object(2), String(3) }
	    _internal2Java.put(Type.NodeSet, new JavaType(nodeListClass, 0)); 
	    _internal2Java.put(Type.NodeSet, new JavaType(nodeClass, 1)); 
	    _internal2Java.put(Type.NodeSet, new JavaType(Object.class, 2));
	    _internal2Java.put(Type.NodeSet, new JavaType(String.class, 3)); 

            // Type.Node -> { Node(0), NodeList(1), Object(2), String(3) }
	    _internal2Java.put(Type.Node, new JavaType(nodeListClass, 0));
	    _internal2Java.put(Type.Node, new JavaType(nodeClass, 1));  
	    _internal2Java.put(Type.Node, new JavaType(Object.class, 2));
	    _internal2Java.put(Type.Node, new JavaType(String.class, 3));

            // Type.ResultTree -> { NodeList(0), Node(1), Object(2), String(3) }
	    _internal2Java.put(Type.ResultTree, new JavaType(nodeListClass, 0));
	    _internal2Java.put(Type.ResultTree, new JavaType(nodeClass, 1)); 
	    _internal2Java.put(Type.ResultTree, new JavaType(Object.class, 2));
	    _internal2Java.put(Type.ResultTree, new JavaType(String.class, 3));

	    _internal2Java.put(Type.Reference, new JavaType(Object.class, 0));

	    // Possible conversions between Java and internal types
	    _java2Internal.put(Boolean.TYPE, Type.Boolean); 
	    _java2Internal.put(Void.TYPE, Type.Void);
	    _java2Internal.put(Character.TYPE, Type.Real); 
	    _java2Internal.put(Byte.TYPE, Type.Real);
	    _java2Internal.put(Short.TYPE, Type.Real);
	    _java2Internal.put(Integer.TYPE, Type.Real);
	    _java2Internal.put(Long.TYPE, Type.Real);
	    _java2Internal.put(Float.TYPE, Type.Real);
	    _java2Internal.put(Double.TYPE, Type.Real);

	    _java2Internal.put(String.class, Type.String);

	    _java2Internal.put(Object.class, Type.Reference);

	    // Conversions from org.w3c.dom.Node/NodeList to internal NodeSet
	    _java2Internal.put(nodeListClass, Type.NodeSet);
	    _java2Internal.put(nodeClass, Type.NodeSet);
	    
	    // Initialize the extension namespace table
	    _extensionNamespaceTable.put(EXT_XALAN, "com.sun.org.apache.xalan.internal.lib.Extensions");
	    _extensionNamespaceTable.put(EXSLT_COMMON, "com.sun.org.apache.xalan.internal.lib.ExsltCommon");
	    _extensionNamespaceTable.put(EXSLT_MATH, "com.sun.org.apache.xalan.internal.lib.ExsltMath");
	    _extensionNamespaceTable.put(EXSLT_SETS, "com.sun.org.apache.xalan.internal.lib.ExsltSets");
	    _extensionNamespaceTable.put(EXSLT_DATETIME, "com.sun.org.apache.xalan.internal.lib.ExsltDatetime");
	    _extensionNamespaceTable.put(EXSLT_STRINGS, "com.sun.org.apache.xalan.internal.lib.ExsltStrings");
	    
	    // Initialize the extension function table
	    _extensionFunctionTable.put(EXSLT_COMMON + ":nodeSet", "nodeset");
	    _extensionFunctionTable.put(EXSLT_COMMON + ":objectType", "objectType");	    
	    _extensionFunctionTable.put(EXT_XALAN + ":nodeset", "nodeset");
	}
	catch (ClassNotFoundException e) {
	    System.err.println(e);
	}
    }
		
    public FunctionCall(QName fname, Vector arguments) {
	_fname = fname;
	_arguments = arguments;
	_type = null;
    }

    public FunctionCall(QName fname) {
	this(fname, EMPTY_ARG_LIST);
    }

    public String getName() {
	return(_fname.toString());
    }

    public void setParser(Parser parser) {
	super.setParser(parser);
	if (_arguments != null) {
	    final int n = _arguments.size();
	    for (int i = 0; i < n; i++) {
		final Expression exp = (Expression)_arguments.elementAt(i);
		exp.setParser(parser);
		exp.setParent(this);
	    }
	}
    }

    public String getClassNameFromUri(String uri) 
    {   
        String className = (String)_extensionNamespaceTable.get(uri);
    
        if (className != null)
            return className;
        else {
            if (uri.startsWith(JAVA_EXT_XSLTC)) {
      	    	int length = JAVA_EXT_XSLTC.length() + 1;
            	return (uri.length() > length) ? uri.substring(length) : EMPTYSTRING;
            }
            else if (uri.startsWith(JAVA_EXT_XALAN)) {
      	    	int length = JAVA_EXT_XALAN.length() + 1;
            	return (uri.length() > length) ? uri.substring(length) : EMPTYSTRING;
            }
            else if (uri.startsWith(JAVA_EXT_XALAN_OLD)) {
      	    	int length = JAVA_EXT_XALAN_OLD.length() + 1;
            	return (uri.length() > length) ? uri.substring(length) : EMPTYSTRING;
            }
            else {
      	    	int index = uri.lastIndexOf('/');
      	    	return (index > 0) ? uri.substring(index+1) : uri;
            }      
        }
    }

    /**
     * Type check a function call. Since different type conversions apply,
     * type checking is different for standard and external (Java) functions.
     */
    public Type typeCheck(SymbolTable stable) 
	throws TypeCheckError 
    {
        if (_type != null) return _type;

	final String namespace = _fname.getNamespace();
	String local = _fname.getLocalPart();

	if (isExtension()) {
	    _fname = new QName(null, null, local);
	    return typeCheckStandard(stable);
	}
	else if (isStandard()) {
	    return typeCheckStandard(stable);
	}
	// Handle extension functions (they all have a namespace)
	else {
	    try {
	    	_className = getClassNameFromUri(namespace);
		  
                final int pos = local.lastIndexOf('.');
		if (pos > 0) {
		    _isStatic = true;
		    if (_className != null && _className.length() > 0) {
		    	_namespace_format = NAMESPACE_FORMAT_PACKAGE;
		     	_className = _className + "." + local.substring(0, pos);
		    }
		    else {
		     	_namespace_format = NAMESPACE_FORMAT_JAVA;
		     	_className = local.substring(0, pos);
		    }
			  
		    _fname = new QName(namespace, null, local.substring(pos + 1));
		}
		else {
		    if (_className != null && _className.length() > 0) {
		    	try {
                            _clazz = ObjectFactory.findProviderClass(
                                _className, ObjectFactory.findClassLoader(), true);
		            _namespace_format = NAMESPACE_FORMAT_CLASS;
		    	}
		    	catch (ClassNotFoundException e) {
		      	    _namespace_format = NAMESPACE_FORMAT_PACKAGE;	
		        }
		    }
		    else
	            	_namespace_format = NAMESPACE_FORMAT_JAVA;