/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

package org.apache.jasper.compiler;

import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Vector;
import java.util.jar.JarFile;
import java.util.zip.ZipEntry;

import javax.el.FunctionMapper;
import javax.servlet.jsp.el.ExpressionEvaluator;


import org.apache.el.ExpressionFactoryImpl;
import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.el.ExpressionEvaluatorImpl;
import org.xml.sax.Attributes;

/** 
 * This class has all the utility method(s).
 * Ideally should move all the bean containers here.
 *
 * @author Mandar Raje.
 * @author Rajiv Mordani.
 * @author Danno Ferrin
 * @author Pierre Delisle
 * @author Shawn Bayern
 * @author Mark Roth
 */
public class JspUtil {

    private static final String WEB_INF_TAGS = "/WEB-INF/tags/";
    private static final String META_INF_TAGS = "/META-INF/tags/";

    // Delimiters for request-time expressions (JSP and XML syntax)
    private static final String OPEN_EXPR  = "<%=";
    private static final String CLOSE_EXPR = "%>";
    private static final String OPEN_EXPR_XML  = "%=";
    private static final String CLOSE_EXPR_XML = "%";

    private static int tempSequenceNumber = 0;
    
    //private static ExpressionEvaluatorImpl expressionEvaluator
    //= new ExpressionEvaluatorImpl();
    
    //tc6
    private final static ExpressionEvaluator expressionEvaluator =
        new ExpressionEvaluatorImpl(new ExpressionFactoryImpl());

    private static final String javaKeywords[] = {
        "abstract", "assert", "boolean", "break", "byte", "case",
        "catch", "char", "class", "const", "continue",
        "default", "do", "double", "else", "enum", "extends",
        "final", "finally", "float", "for", "goto",
        "if", "implements", "import", "instanceof", "int",
        "interface", "long", "native", "new", "package",
        "private", "protected", "public", "return", "short",
        "static", "strictfp", "super", "switch", "synchronized",
        "this", "throws", "transient", "try", "void",
        "volatile", "while" };

    public static final int CHUNKSIZE = 1024;
        
    public static char[] removeQuotes(char []chars) {
        CharArrayWriter caw = new CharArrayWriter();
        for (int i = 0; i < chars.length; i++) {
            if (chars[i] == '%' && chars[i+1] == '\\' &&
                chars[i+2] == '>') {
                caw.write('%');
                caw.write('>');
                i = i + 2;
            } else {
                caw.write(chars[i]);
            }
        }
        return caw.toCharArray();
    }

    public static char[] escapeQuotes (char []chars) {
        // Prescan to convert %\> to %>
        String s = new String(chars);
        while (true) {
            int n = s.indexOf("%\\>");
            if (n < 0)
                break;
            StringBuffer sb = new StringBuffer(s.substring(0, n));
            sb.append("%>");
            sb.append(s.substring(n + 3));
            s = sb.toString();
        }
        chars = s.toCharArray();
        return (chars);


        // Escape all backslashes not inside a Java string literal
        /*
        CharArrayWriter caw = new CharArrayWriter();
        boolean inJavaString = false;
        for (int i = 0; i < chars.length; i++) {
            if (chars[i] == '"') inJavaString = !inJavaString;
            // escape out the escape character
            if (!inJavaString && (chars[i] == '\\')) caw.write('\\');
            caw.write(chars[i]);
        }
        return caw.toCharArray();
        */
    }

    /**
     * Checks if the token is a runtime expression.
     * In standard JSP syntax, a runtime expression starts with '<%' and
     * ends with '%>'. When the JSP document is in XML syntax, a runtime
     * expression starts with '%=' and ends with '%'.
     *
     * @param token The token to be checked
     * return whether the token is a runtime expression or not.
     */
    public static boolean isExpression(String token, boolean isXml) {
    String openExpr;
    String closeExpr;
    if (isXml) {
        openExpr = OPEN_EXPR_XML;
        closeExpr = CLOSE_EXPR_XML;
    } else {
        openExpr = OPEN_EXPR;
        closeExpr = CLOSE_EXPR;
    }
    if (token.startsWith(openExpr) && token.endsWith(closeExpr)) {
        return true;
    } else {
        return false;
    }
    }

    /**
     * @return the "expression" part of a runtime expression, 
     * taking the delimiters out.
     */
    public static String getExpr (String expression, boolean isXml) {
    String returnString;
    String openExpr;
    String closeExpr;
    if (isXml) {
        openExpr = OPEN_EXPR_XML;
        closeExpr = CLOSE_EXPR_XML;
    } else {
        openExpr = OPEN_EXPR;
        closeExpr = CLOSE_EXPR;
    }
    int length = expression.length();
    if (expression.startsWith(openExpr) && 
                expression.endsWith(closeExpr)) {
        returnString = expression.substring(
                               openExpr.length(), length - closeExpr.length());
    } else {
        returnString = "";
    }
    return returnString;
    }

    /**
     * Takes a potential expression and converts it into XML form
     */
    public static String getExprInXml(String expression) {
        String returnString;
        int length = expression.length();

        if (expression.startsWith(OPEN_EXPR) 
                && expression.endsWith(CLOSE_EXPR)) {
            returnString = expression.substring (1, length - 1);
        } else {
            returnString = expression;
        }

        return escapeXml(returnString);
    }

    /**
     * Checks to see if the given scope is valid.
     *
     * @param scope The scope to be checked
     * @param n The Node containing the 'scope' attribute whose value is to be
     * checked
     * @param err error dispatcher
     *
     * @throws JasperException if scope is not null and different from
     * &quot;page&quot;, &quot;request&quot;, &quot;session&quot;, and
     * &quot;application&quot;
     */
    public static void checkScope(String scope, Node n, ErrorDispatcher err)
            throws JasperException {
    if (scope != null && !scope.equals("page") && !scope.equals("request")
        && !scope.equals("session") && !scope.equals("application")) {
        err.jspError(n, "jsp.error.invalid.scope", scope);
    }
    }

    /**
     * Checks if all mandatory attributes are present and if all attributes
     * present have valid names.  Checks attributes specified as XML-style
     * attributes as well as attributes specified using the jsp:attribute
     * standard action. 
     */
    public static void checkAttributes(String typeOfTag,
                       Node n,
                       ValidAttribute[] validAttributes,
                       ErrorDispatcher err)
                throws JasperException {
        Attributes attrs = n.getAttributes();
        Mark start = n.getStart();
    boolean valid = true;

        // AttributesImpl.removeAttribute is broken, so we do this...
        int tempLength = (attrs == null) ? 0 : attrs.getLength();
    Vector temp = new Vector(tempLength, 1);
        for (int i = 0; i < tempLength; i++) {
            String qName = attrs.getQName(i);
            if ((!qName.equals("xmlns")) && (!qName.startsWith("xmlns:")))
                temp.addElement(qName);
        }

        // Add names of attributes specified using jsp:attribute
        Node.Nodes tagBody = n.getBody();
        if( tagBody != null ) {
            int numSubElements = tagBody.size();
            for( int i = 0; i < numSubElements; i++ ) {
                Node node = tagBody.getNode( i );
                if( node instanceof Node.NamedAttribute ) {
                    String attrName = node.getAttributeValue( "name" );
                    temp.addElement( attrName );
            // Check if this value appear in the attribute of the node
            if (n.getAttributeValue(attrName) != null) {
            err.jspError(n, "jsp.error.duplicate.name.jspattribute",
                    attrName);
            }
                }
                else {
                    // Nothing can come before jsp:attribute, and only
                    // jsp:body can come after it.
                    break;
                }
            }
        }

    /*
     * First check to see if all the mandatory attributes are present.
     * If so only then proceed to see if the other attributes are valid
     * for the particular tag.
     */
    String missingAttribute = null;

    for (int i = 0; i < validAttributes.length; i++) {
        int attrPos;    
        if (validAttributes[i].mandatory) {
                attrPos = temp.indexOf(validAttributes[i].name);
        if (attrPos != -1) {
            temp.remove(attrPos);
            valid = true;
        } else {
            valid = false;
            missingAttribute = validAttributes[i].name;
            break;
        }
        }
    }

    // If mandatory attribute is missing then the exception is thrown
    if (!valid)
        err.jspError(start, "jsp.error.mandatory.attribute", typeOfTag,
             missingAttribute);

    // Check to see if there are any more attributes for the specified tag.
        int attrLeftLength = temp.size();
    if (attrLeftLength == 0)
        return;

    // Now check to see if the rest of the attributes are valid too.
    String attribute = null;

    for (int j = 0; j < attrLeftLength; j++) {
        valid = false;
        attribute = (String) temp.elementAt(j);
        for (int i = 0; i < validAttributes.length; i++) {
        if (attribute.equals(validAttributes[i].name)) {
            valid = true;
            break;
        }
        }
        if (!valid)
        err.jspError(start, "jsp.error.invalid.attribute", typeOfTag,
                 attribute);
    }
    // XXX *could* move EL-syntax validation here... (sb)
    }
    
    public static String escapeQueryString(String unescString) {
    if ( unescString == null )
        return null;
    
    String escString    = "";
    String shellSpChars = "\\\"";
    
    for(int index=0; index<unescString.length(); index++) {
        char nextChar = unescString.charAt(index);
        
        if( shellSpChars.indexOf(nextChar) != -1 )
        escString += "\\";
        
        escString += nextChar;
    }
    return escString;
    }
 
    /**
     *  Escape the 5 entities defined by XML.
     */
    public static String escapeXml(String s) {
        if (s == null) return null;
        StringBuffer sb = new StringBuffer();
        for(int i=0; i<s.length(); i++) {
            char c = s.charAt(i);
            if (c == '<') {
                sb.append("&lt;");
            } else if (c == '>') {
                sb.append("&gt;");
            } else if (c == '\'') {
                sb.append("&apos;");
            } else if (c == '&') {
                sb.append("&amp;");
            } else if (c == '"') {
                sb.append("&quot;");
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }

    /**
     * Replaces any occurrences of the character <tt>replace</tt> with the
     * string <tt>with</tt>.
     */
    public static String replace(String name, char replace, String with) {
    StringBuffer buf = new StringBuffer();
    int begin = 0;
    int end;
    int last = name.length();

    while (true) {
        end = name.indexOf(replace, begin);
        if (end < 0) {
        end = last;
        }
        buf.append(name.substring(begin, end));
        if (end == last) {
        break;
        }
        buf.append(with);
        begin = end + 1;
    }
    
    return buf.toString();
    }

    public static class ValidAttribute {
    String name;
    boolean mandatory;
    boolean rtexprvalue;    // not used now

    public ValidAttribute (String name, boolean mandatory,
            boolean rtexprvalue )
        {
        this.name = name;
        this.mandatory = mandatory;
            this.rtexprvalue = rtexprvalue;
        }

       public ValidAttribute (String name, boolean mandatory) {
            this( name, mandatory, false );
    }

    public ValidAttribute (String name) {
        this (name, false);
    }
    }
    
    /**
     * Convert a String value to 'boolean'.
     * Besides the standard conversions done by
     * Boolean.valueOf(s).booleanValue(), the value "yes"
     * (ignore case) is also converted to 'true'. 
     * If 's' is null, then 'false' is returned.
     *
     * @param s the string to be converted
     * @return the boolean value associated with the string s
     */
    public static boolean booleanValue(String s) {
    boolean b = false;
    if (s != null) {
        if (s.equalsIgnoreCase("yes")) {
        b = true;
        } else {
        b = Boolean.valueOf(s).booleanValue();
        }
    }
    return b;
    }

    /**
     * Returns the <tt>Class</tt> object associated with the class or
     * interface with the given string name.
     *
     * <p> The <tt>Class</tt> object is determined by passing the given string
     * name to the <tt>Class.forName()</tt> method, unless the given string
     * name represents a primitive type, in which case it is converted to a
     * <tt>Class</tt> object by appending ".class" to it (e.g., "int.class").
     */
    public static Class toClass(String type, ClassLoader loader)
        throws ClassNotFoundException {

    Class c = null;
    int i0 = type.indexOf('[');
    int dims = 0;
    if (i0 > 0) {
        // This is an array.  Count the dimensions
        for (int i = 0; i < type.length(); i++) {
        if (type.charAt(i) == '[')
            dims++;
        }
        type = type.substring(0, i0);
    }

    if ("boolean".equals(type))
        c = boolean.class;
    else if ("char".equals(type))
        c = char.class;
    else if ("byte".equals(type))
        c =  byte.class;
    else if ("short".equals(type))
        c = short.class;
    else if ("int".equals(type))
        c = int.class;
    else if ("long".equals(type))
        c = long.class;
    else if ("float".equals(type))
        c = float.class;
    else if ("double".equals(type))
        c = double.class;
    else if ("void".equals(type))
        c = void.class;
    else if (type.indexOf('[') < 0)
        c = loader.loadClass(type);

    if (dims == 0)
        return c;

    if (dims == 1)
        return java.lang.reflect.Array.newInstance(c, 1).getClass();

    // Array of more than i dimension
    return java.lang.reflect.Array.newInstance(c, new int[dims]).getClass();
    }
    
    /**
     * Produces a String representing a call to the EL interpreter.
     * @param expression a String containing zero or more "${}" expressions
     * @param expectedType the expected type of the interpreted result
     * @param fnmapvar Variable pointing to a function map.
     * @param XmlEscape True if the result should do XML escaping
     * @return a String representing a call to the EL interpreter.
     */
    public static String interpreterCall(boolean isTagFile,
                     String expression,
                                         Class expectedType,
                                         String fnmapvar,
                                         boolean XmlEscape ) 
    {
        /*
         * Determine which context object to use.
         */
    String jspCtxt = null;
    if (isTagFile)
        jspCtxt = "this.getJspContext()";
    else
        jspCtxt = "_jspx_page_context";

    /*
         * Determine whether to use the expected type's textual name
     * or, if it's a primitive, the name of its correspondent boxed
     * type.
         */
    String targetType = getCanonicalName(expectedType);
    String primitiveConverterMethod = null;
    if (expectedType.isPrimitive()) {
        if (expectedType.equals(Boolean.TYPE)) {
        targetType = Boolean.class.getName();
        primitiveConverterMethod = "booleanValue";
        } else if (expectedType.equals(Byte.TYPE)) {
        targetType = Byte.class.getName();
        primitiveConverterMethod = "byteValue";
        } else if (expectedType.equals(Character.TYPE)) {
        targetType = Character.class.getName();
        primitiveConverterMethod = "charValue";
        } else if (expectedType.equals(Short.TYPE)) {
        targetType = Short.class.getName();
        primitiveConverterMethod = "shortValue";
        } else if (expectedType.equals(Integer.TYPE)) {
        targetType = Integer.class.getName();
        primitiveConverterMethod = "intValue";
        } else if (expectedType.equals(Long.TYPE)) {
        targetType = Long.class.getName();
        primitiveConverterMethod = "longValue";
        } else if (expectedType.equals(Float.TYPE)) {
        targetType = Float.class.getName();
        primitiveConverterMethod = "floatValue";
        } else if (expectedType.equals(Double.TYPE)) { 
        targetType = Double.class.getName();
        primitiveConverterMethod = "doubleValue";
        }
    }
 
    if (primitiveConverterMethod != null) {
        XmlEscape = false;
    }

    /*
         * Build up the base call to the interpreter.
         */
        // XXX - We use a proprietary call to the interpreter for now
        // as the current standard machinery is inefficient and requires
        // lots of wrappers and adapters.  This should all clear up once
        // the EL interpreter moves out of JSTL and into its own project.
        // In the future, this should be replaced by code that calls
        // ExpressionEvaluator.parseExpression() and then cache the resulting
        // expression objects.  The interpreterCall would simply select
        // one of the pre-cached expressions and evaluate it.
        // Note that PageContextImpl implements VariableResolver and
        // the generated Servlet/SimpleTag implements FunctionMapper, so
        // that machinery is already in place (mroth).
    targetType = toJavaSourceType(targetType);
    StringBuffer call = new StringBuffer(
             "(" + targetType + ") "
               + "org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate"
               + "(" + Generator.quote(expression) + ", "
               +       targetType + ".class, "
           +       "(PageContext)" + jspCtxt 
               +       ", " + fnmapvar
           + ", " + XmlEscape
               + ")");
 
    /*
         * Add the primitive converter method if we need to.
         */
    if (primitiveConverterMethod != null) {
        call.insert(0, "(");
        call.append(")." + primitiveConverterMethod + "()");
    }
 
    return call.toString();
    }

    /**
     * Validates the syntax of all ${} expressions within the given string.
     * @param where the approximate location of the expressions in the JSP page
     * @param expressions a string containing zero or more "${}" expressions
     * @param err an error dispatcher to use
     * @deprecated now delegated to the org.apache.el Package
     */
    public static void validateExpressions(Mark where,
                                           String expressions,
                                           Class expectedType,
                                           FunctionMapper functionMapper,
                                           ErrorDispatcher err)
            throws JasperException {

//        try {
//            
//            JspUtil.expressionEvaluator.parseExpression( expressions, 
//                expectedType, functionMapper );
//        }
//        catch( ELParseException e ) {
//            err.jspError(where, "jsp.error.invalid.expression", expressions,
//                e.toString() );
//        }
//        catch( ELException e ) {
//            err.jspError(where, "jsp.error.invalid.expression", expressions,
//                e.toString() );
//        }
    }

    /**
     * Resets the temporary variable name.
     * (not thread-safe)
     * @deprecated
     */
    public static void resetTemporaryVariableName() {
        tempSequenceNumber = 0;
    }

    /**
     * Generates a new temporary variable name.
     * (not thread-safe)
     * @deprecated
     */
    public static String nextTemporaryVariableName() {
        return Constants.TEMP_VARIABLE_NAME_PREFIX + (tempSequenceNumber++);
    }

    public static String coerceToPrimitiveBoolean(String s,
                          boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToBoolean(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "false";
        else
        return Boolean.valueOf(s).toString();
    }
    }

    public static String coerceToBoolean(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Boolean) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Boolean.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Boolean(false)";
        } else {
        // Detect format error at translation time
        return "new Boolean(" + Boolean.valueOf(s).toString() + ")";
        }
    }
    }

    public static String coerceToPrimitiveByte(String s,
                           boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToByte(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "(byte) 0";
        else
        return "((byte)" + Byte.valueOf(s).toString() + ")";
    }
    }

    public static String coerceToByte(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Byte) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Byte.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Byte((byte) 0)";
        } else {
        // Detect format error at translation time
        return "new Byte((byte)" + Byte.valueOf(s).toString() + ")";
        }
    }
    }

    public static String coerceToChar(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToChar(" + s + ")";
    } else {
        if (s == null || s.length() == 0) {
        return "(char) 0";
        } else {
        char ch = s.charAt(0);
        // this trick avoids escaping issues
        return "((char) " + (int) ch + ")";
        }
    }
    }

    public static String coerceToCharacter(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Character) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Character.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Character((char) 0)";
        } else {
        char ch = s.charAt(0);
        // this trick avoids escaping issues
        return "new Character((char) " + (int) ch + ")";
        }
    }
    }

    public static String coerceToPrimitiveDouble(String s,
                         boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToDouble(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "(double) 0";
        else
        return Double.valueOf(s).toString();
    }
    }

    public static String coerceToDouble(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Double) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Double.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Double(0)";
        } else {
        // Detect format error at translation time
        return "new Double(" + Double.valueOf(s).toString() + ")";
        }
    }
    }

    public static String coerceToPrimitiveFloat(String s,
                        boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToFloat(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "(float) 0";
        else
        return Float.valueOf(s).toString() + "f";
    }
    }

    public static String coerceToFloat(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Float) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Float.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Float(0)";
        } else {
        // Detect format error at translation time
        return "new Float(" + Float.valueOf(s).toString() + "f)";
        }
    }
    }

    public static String coerceToInt(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToInt(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "0";
        else
        return Integer.valueOf(s).toString();
    }
    }

    public static String coerceToInteger(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Integer) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Integer.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Integer(0)";
        } else {
        // Detect format error at translation time
        return "new Integer(" + Integer.valueOf(s).toString() + ")";
        }
    }
    }

    public static String coerceToPrimitiveShort(String s,
                        boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToShort(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "(short) 0";
        else
        return "((short) " + Short.valueOf(s).toString() + ")";
    }
    }
    
    public static String coerceToShort(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Short) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Short.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Short((short) 0)";
        } else {
        // Detect format error at translation time
        return "new Short(\"" + Short.valueOf(s).toString() + "\")";
        }
    }
    }
    
    public static String coerceToPrimitiveLong(String s,
                           boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "org.apache.jasper.runtime.JspRuntimeLibrary.coerceToLong(" + s + ")";
    } else {
        if (s == null || s.length() == 0)
        return "(long) 0";
        else
        return Long.valueOf(s).toString() + "l";
    }
    }

    public static String coerceToLong(String s, boolean isNamedAttribute) {
    if (isNamedAttribute) {
        return "(Long) org.apache.jasper.runtime.JspRuntimeLibrary.coerce(" + s + ", Long.class)";
    } else {
        if (s == null || s.length() == 0) {
        return "new Long(0)";
        } else {
        // Detect format error at translation time
        return "new Long(" + Long.valueOf(s).toString() + "l)";
        }
    }
    }

    public static InputStream getInputStream(String fname, JarFile jarFile,
                         JspCompilationContext ctxt,
                         ErrorDispatcher err)
        throws JasperException, IOException {

        InputStream in = null;

    if (jarFile != null) {
        String jarEntryName = fname.substring(1, fname.length());
        ZipEntry jarEntry = jarFile.getEntry(jarEntryName);
        if (jarEntry == null) {
        err.jspError("jsp.error.file.not.found", fname);
        }
        in = jarFile.getInputStream(jarEntry);
    } else {
        in = ctxt.getResourceAsStream(fname);
    }

    if (in == null) {
        err.jspError("jsp.error.file.not.found", fname);
    }

    return in;
    }

    /**
     * Gets the fully-qualified class name of the tag handler corresponding to
     * the given tag file path.
     *
     * @param path Tag file path
     * @param err Error dispatcher
     *
     * @return Fully-qualified class name of the tag handler corresponding to 
     * the given tag file path
     * 
     * @deprecated Use {@link #getTagHandlerClassName(String, String,
     *             ErrorDispatcher)}
     *             See https://issues.apache.org/bugzilla/show_bug.cgi?id=46471
     */
    public static String getTagHandlerClassName(String path,
                        ErrorDispatcher err)
                throws JasperException {
        return getTagHandlerClassName(path, null, err);
    }
    
    /**
     * Gets the fully-qualified class name of the tag handler corresponding to
     * the given tag file path.
     * 
     * @param path
     *            Tag file path
     * @param err
     *            Error dispatcher
     * 
     * @return Fully-qualified class name of the tag handler corresponding to
     *         the given tag file path
     */
    public static String getTagHandlerClassName(String path, String urn,
            ErrorDispatcher err) throws JasperException {

        String className = null;
        int begin = 0;
        int index;
        
        index = path.lastIndexOf(".tag");
        if (index == -1) {
            err.jspError("jsp.error.tagfile.badSuffix", path);
        }

        //It's tempting to remove the ".tag" suffix here, but we can't.
        //If we remove it, the fully-qualified class name of this tag
        //could conflict with the package name of other tags.
        //For instance, the tag file
        //    /WEB-INF/tags/foo.tag
        //would have fully-qualified class name
        //    org.apache.jsp.tag.web.foo
        //which would conflict with the package name of the tag file
        //    /WEB-INF/tags/foo/bar.tag

        index = path.indexOf(WEB_INF_TAGS);
        if (index != -1) {
            className = "org.apache.jsp.tag.web.";
            begin = index + WEB_INF_TAGS.length();
        } else {
            index = path.indexOf(META_INF_TAGS);
            if (index != -1) {
                className = getClassNameBase(urn);
                begin = index + META_INF_TAGS.length();
            } else {
                err.jspError("jsp.error.tagfile.illegalPath", path);
            }
        }

        className += makeJavaPackage(path.substring(begin));
  
       return className;
    }

    private static String getClassNameBase(String urn) {
        StringBuffer base = new StringBuffer("org.apache.jsp.tag.meta.");
        if (urn != null) {
            base.append(makeJavaPackage(urn));
            base.append('.');
        }
        return base.toString();
    }

    /**
     * Converts the given path to a Java package or fully-qualified class name
     *
     * @param path Path to convert
     *
     * @return Java package corresponding to the given path
     */
    public static final String makeJavaPackage(String path) {
        String classNameComponents[] = split(path,"/");
        StringBuffer legalClassNames = new StringBuffer();
        for (int i = 0; i < classNameComponents.length; i++) {
            legalClassNames.append(makeJavaIdentifier(classNameComponents[i]));
            if (i < classNameComponents.length - 1) {
                legalClassNames.append('.');
            }
        }
        return legalClassNames.toString();
    }

    /**
     * Splits a string into it's components.
     * @param path String to split
     * @param pat Pattern to split at
     * @return the components of the path
     */
    private static final String [] split(String path, String pat) {
        Vector comps = new Vector();
        int pos = path.indexOf(pat);
        int start = 0;
        while( pos >= 0 ) {
            if(pos > start ) {
                String comp = path.substring(start,pos);
                comps.add(comp);
            }
            start = pos + pat.length();
            pos = path.indexOf(pat,start);
        }
        if( start < path.length()) {
            comps.add(path.substring(start));
        }
        String [] result = new String[comps.size()];
        for(int i=0; i < comps.size(); i++) {
            result[i] = (String)comps.elementAt(i);
        }
        return result;
    }
            
    /**
     * Converts the given identifier to a legal Java identifier
     *
     * @param identifier Identifier to convert
     *
     * @return Legal Java identifier corresponding to the given identifier
     */
    public static final String makeJavaIdentifier(String identifier) {
        return makeJavaIdentifier(identifier, true);
    }

    /**
     * Converts the given identifier to a legal Java identifier
     * to be used for JSP Tag file attribute names. 
     * 
     * @param identifier
     *            Identifier to convert
     * 
     * @return Legal Java identifier corresponding to the given identifier
     */
    public static final String makeJavaIdentifierForAttribute(String identifier) {
        return makeJavaIdentifier(identifier, false);
    }

    /**
     * Converts the given identifier to a legal Java identifier.
     * 
     * @param identifier
     *            Identifier to convert
     * 
     * @return Legal Java identifier corresponding to the given identifier
     */
    private static final String makeJavaIdentifier(String identifier,
            boolean periodToUnderscore) {
        StringBuilder modifiedIdentifier =
            new StringBuilder(identifier.length());
        if (!Character.isJavaIdentifierStart(identifier.charAt(0))) {
            modifiedIdentifier.append('_');
        }
        for (int i = 0; i < identifier.length(); i++) {
            char ch = identifier.charAt(i);
            if (Character.isJavaIdentifierPart(ch) &&
                    (ch != '_' || !periodToUnderscore)) {
                modifiedIdentifier.append(ch);
            } else if (ch == '.' && periodToUnderscore) {
                modifiedIdentifier.append('_');
            } else {
                modifiedIdentifier.append(mangleChar(ch));
            }
        }
        if (isJavaKeyword(modifiedIdentifier.toString())) {
            modifiedIdentifier.append('_');
        }
        return modifiedIdentifier.toString();
    }
    
    /**
     * Mangle the specified character to create a legal Java class name.
     */
    public static final String mangleChar(char ch) {
        char[] result = new char[5];
        result[0] = '_';
        result[1] = Character.forDigit((ch >> 12) & 0xf, 16);
        result[2] = Character.forDigit((ch >> 8) & 0xf, 16);
        result[3] = Character.forDigit((ch >> 4) & 0xf, 16);
        result[4] = Character.forDigit(ch & 0xf, 16);
        return new String(result);
    }

    /**
     * Test whether the argument is a Java keyword
     */
    public static boolean isJavaKeyword(String key) {
        int i = 0;
        int j = javaKeywords.length;
        while (i < j) {
            int k = (i+j)/2;
            int result = javaKeywords[k].compareTo(key);
            if (result == 0) {
                return true;
            }
            if (result < 0) {
                i = k+1;
            } else {
                j = k;
            }
        }
        return false;
    }

    /**
     * Converts the given Xml name to a legal Java identifier.  This is
     * slightly more efficient than makeJavaIdentifier in that we only need
     * to worry about '.', '-', and ':' in the string.  We also assume that
     * the resultant string is further concatenated with some prefix string
     * so that we don't have to worry about it being a Java key word.
     *
     * @param name Identifier to convert
     *
     * @return Legal Java identifier corresponding to the given identifier
     */
    public static final String makeXmlJavaIdentifier(String name) {
        if (name.indexOf('-') >= 0)
            name = replace(name, '-', "$1");
        if (name.indexOf('.') >= 0)
            name = replace(name, '.', "$2");
        if (name.indexOf(':') >= 0)
            name = replace(name, ':', "$3");
        return name;
    }

    static InputStreamReader getReader(String fname, String encoding,
            JarFile jarFile,
            JspCompilationContext ctxt,
            ErrorDispatcher err)
    throws JasperException, IOException {

        return getReader(fname, encoding, jarFile, ctxt, err, 0);
    }

    static InputStreamReader getReader(String fname, String encoding,
            JarFile jarFile,
            JspCompilationContext ctxt,
            ErrorDispatcher err, int skip)
    throws JasperException, IOException {

        InputStreamReader reader = null;
        InputStream in = getInputStream(fname, jarFile, ctxt, err);
        for (int i = 0; i < skip; i++) {
            in.read();
        }
        try {
            reader = new InputStreamReader(in, encoding);
        } catch (UnsupportedEncodingException ex) {
            err.jspError("jsp.error.unsupported.encoding", encoding);
        }

        return reader;
    }
    
    /**
     * Handles taking input from TLDs
     * 'java.lang.Object' -> 'java.lang.Object.class'
     * 'int' -> 'int.class'
     * 'void' -> 'Void.TYPE'
     * 'int[]' -> 'int[].class'
     */
    public static String toJavaSourceTypeFromTld(String type) {
        if (type == null || "void".equals(type)) {
            return "Void.TYPE";
        }
        return type + ".class";
    }

    /**
     * Class.getName() return arrays in the form "[[[<et>", where et,
     * the element type can be one of ZBCDFIJS or L<classname>;
     * It is converted into forms that can be understood by javac.
     */
    public static String toJavaSourceType(String type) {

    if (type.charAt(0) != '[') {
        return type;
    }

    int dims = 1;
    String t = null;
    for (int i = 1; i < type.length(); i++) {
        if (type.charAt(i) == '[') {
        dims++;
        } else {
        switch (type.charAt(i)) {
        case 'Z': t = "boolean"; break;
        case 'B': t = "byte"; break;
        case 'C': t = "char"; break;
        case 'D': t = "double"; break;
        case 'F': t = "float"; break;
        case 'I': t = "int"; break;
        case 'J': t = "long"; break;
        case 'S': t = "short"; break;
        case 'L': t = type.substring(i+1, type.indexOf(';')); break;
        }
        break;
        }
    }
    StringBuffer resultType = new StringBuffer(t);
    for (; dims > 0; dims--) {
        resultType.append("[]");
    }
    return resultType.toString();
    }

    /**
     * Compute the canonical name from a Class instance.  Note that a
     * simple replacment of '$' with '.' of a binary name would not work,
     * as '$' is a legal Java Identifier character.
     * @param c A instance of java.lang.Class
     * @return  The canonical name of c.
     */
    public static String getCanonicalName(Class c) {

        String binaryName = c.getName();
        c = c.getDeclaringClass();

        if (c == null) {
            return binaryName;
        }

        StringBuffer buf = new StringBuffer(binaryName);
        do {
            buf.setCharAt(c.getName().length(), '.');
            c = c.getDeclaringClass();
        } while ( c != null);

        return buf.toString();
    }
}