libjava/gnu/java/lang/reflect/TypeSignature.java - gcc - Git at Google

 /* TypeSignature.java -- Class used to compute type signatures
    Copyright (C) 1998 Free Software Foundation, Inc.

 This file is part of GNU Classpath.

 GNU Classpath is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2, or (at your option)
 any later version.

 GNU Classpath is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with GNU Classpath; see the file COPYING.  If not, write to the
 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 02111-1307 USA.

 As a special exception, if you link this library with other files to
 produce an executable, this library does not by itself cause the
 resulting executable to be covered by the GNU General Public License.
 This exception does not however invalidate any other reasons why the
 executable file might be covered by the GNU General Public License. */


 package gnu.java.lang.reflect;

 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;

 /**
    This class provides static methods that can be used to compute
    type-signatures of <code>Class</code>s or <code>Member</code>s.
    More specific methods are also provided for computing the
    type-signature of <code>Constructor</code>s and
    <code>Method</code>s.  Methods are also provided to go in the
    reverse direction.
 */
 public class TypeSignature
 {

   /**
      Returns a <code>String</code> representing the type-encoding of
      CLAZZ.  Type-encodings are computed as follows:

      <pre>
      boolean -> "Z"
      byte    -> "B"
      char    -> "C"
      double  -> "D"
      float   -> "F"
      int     -> "I"
      long    -> "J"
      short   -> "S"
      void    -> "V"
      arrays  -> "[" + type-encoding of component type
      object  -> "L"
                  + fully qualified class name with "."'s replaced by "/"'s
                  + ";"</pre>
   */
   public static String getEncodingOfClass( Class clazz )
   {
     if( clazz.isPrimitive() )
     {
       if( clazz == Boolean.TYPE )
 	return "Z";
       if( clazz == Byte.TYPE )
 	return "B";
       if( clazz == Character.TYPE )
 	return "C";
       if( clazz == Double.TYPE )
 	return "D";
       if( clazz == Float.TYPE )
 	return "F";
       if( clazz == Integer.TYPE )
 	return "I";
       if( clazz == Long.TYPE )
 	return "J";
       if( clazz == Short.TYPE )
 	return "S";
       if( clazz == Void.TYPE )
 	return "V";
       else
 	throw new RuntimeException( "Unknown primitive class " + clazz );
     }
     else if( clazz.isArray() )
     {
       return '[' + getEncodingOfClass( clazz.getComponentType() );
     }
     else
     {
       String classname = clazz.getName();
       int name_len = classname.length();
       char[] buf = new char[ name_len + 2 ];
       buf[0] = 'L';
       classname.getChars( 0, name_len, buf, 1 );

       int i;
       for( i=1; i <= name_len; i++ )
       {
 	if( buf[i] == '.' )
 	  buf[i] = '/';
       }

       buf[i] = ';';
       return new String( buf );
     }
   }


   /**
      This function is the inverse of <code>getEncodingOfClass</code>.

      @see getEncodingOfClass

      @exception ClassNotFoundException If class encoded as type_code
      cannot be located.
   */
   public static Class getClassForEncoding( String type_code )
     throws ClassNotFoundException
   {
     if( type_code.equals( "B" ) )
       return Byte.TYPE;
     if( type_code.equals( "C" ) )
       return Character.TYPE;
     if( type_code.equals( "D" ) )
       return Double.TYPE;
     if( type_code.equals( "F" ) )
       return Float.TYPE;
     if( type_code.equals( "I" ) )
       return Integer.TYPE;
     if( type_code.equals( "J" ) )
       return Long.TYPE;
     if( type_code.equals( "S" ) )
       return Short.TYPE;
     if( type_code.equals( "Z" ) )
       return Boolean.TYPE;
     if( type_code.charAt( 0 ) == 'L' )
     {
       return Class.forName(
 	type_code.substring( 1, type_code.length() - 1 ).replace( '/', '.' ));
     }
     if( type_code.charAt( 0 ) == '[' )
     {
       int last_bracket = type_code.lastIndexOf( '[' );
       String brackets = type_code.substring( 0, last_bracket + 1 );
       String component = type_code.substring( last_bracket + 1 );

 // ??? This is what the Classpath implementation did, but I don't
 // think that it's correct.  The JLS says that Class.forName takes the
 // classname of an array element in fully qualified form, whereas this
 // code is tring to strip off the punctuation.

 //        if( component.charAt( 0 ) == 'L' )
 //  	component =
 //  	  component.substring( 1, component.length() - 1 ).replace('/', '.');

       if( component.charAt( 0 ) == 'L' )
   	component = component.replace('/', '.');

       return Class.forName( brackets + component );
     }
     else
       throw new ClassNotFoundException( "Type code cannot be parsed as a valid class name" );
   }


   /**
      Returns a <code>String</code> representing the type-encoding of
      M.  The type-encoding of a method is:

      "(" + type-encodings of parameter types + ")"
      + type-encoding of return type
   */
   public static String getEncodingOfMethod( Method m )
   {
     String returnEncoding = getEncodingOfClass( m.getReturnType() );
     Class[] paramTypes = m.getParameterTypes();
     String[] paramEncodings = new String[ paramTypes.length ];

     String paramEncoding;
     int size = 2; // make room for parens
     for( int i=0; i < paramTypes.length; i++ )
     {
       paramEncoding = getEncodingOfClass( paramTypes[i] );
       size += paramEncoding.length();
       paramEncodings[i] = paramEncoding;
     }

     size += returnEncoding.length();

     StringBuffer buf = new StringBuffer( size );
     buf.append( '(' );

     for( int i=0; i < paramTypes.length; i++ )
     {
       buf.append( paramEncodings[i] );
     }

     buf.append( ')' );
     buf.append( returnEncoding );

     return buf.toString();
   }


   /**
      Returns a <code>String</code> representing the type-encoding of
      C.  The type-encoding of a method is:

      "(" + type-encodings of parameter types + ")V"
   */
   public static String getEncodingOfConstructor( Constructor c )
   {
     Class[] paramTypes = c.getParameterTypes();
     String[] paramEncodings = new String[ paramTypes.length ];

     String paramEncoding;
     int size = 3; // make room for parens and V for return type
     for( int i=0; i < paramTypes.length; i++ )
     {
       paramEncoding = getEncodingOfClass( paramTypes[i] );
       size += paramEncoding.length();
       paramEncodings[i] = paramEncoding;
     }

     StringBuffer buf = new StringBuffer( size );
     buf.append( '(' );

     for( int i=0; i < paramTypes.length; i++ )
     {
       buf.append( paramEncodings[i] );
     }

     buf.append( ")V" );

     return buf.toString();
   }


   /**
      Returns a <code>String</code> representing the type-encoding of
      MEM.  <code>Constructor</code>s are handled by
      <code>getEncodingOfConstructor</code>.  <code>Method</code>s are
      handled by <code>getEncodingOfMethod</code>.  <code>Field</code>s
      are handled by returning the encoding of the type of the
      <code>Field</code>.
   */
   public static String getEncodingOfMember( Member mem )
   {
     if( mem instanceof Constructor )
       return getEncodingOfConstructor( (Constructor)mem );
     if( mem instanceof Method )
       return getEncodingOfMethod( (Method)mem );
     else // Field
       return getEncodingOfClass( ((Field)mem).getType() );
   }
 }
	/* TypeSignature.java -- Class used to compute type signatures
	Copyright (C) 1998 Free Software Foundation, Inc.

	This file is part of GNU Classpath.

	GNU Classpath is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	GNU Classpath is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with GNU Classpath; see the file COPYING. If not, write to the
	Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	02111-1307 USA.

	As a special exception, if you link this library with other files to
	produce an executable, this library does not by itself cause the
	resulting executable to be covered by the GNU General Public License.
	This exception does not however invalidate any other reasons why the
	executable file might be covered by the GNU General Public License. */


	package gnu.java.lang.reflect;

	import java.lang.reflect.Constructor;
	import java.lang.reflect.Field;
	import java.lang.reflect.Member;
	import java.lang.reflect.Method;

	/**
	This class provides static methods that can be used to compute
	type-signatures of <code>Class</code>s or <code>Member</code>s.
	More specific methods are also provided for computing the
	type-signature of <code>Constructor</code>s and
	<code>Method</code>s. Methods are also provided to go in the
	reverse direction.
	*/
	public class TypeSignature
	{

	/**
	Returns a <code>String</code> representing the type-encoding of
	CLAZZ. Type-encodings are computed as follows:

	<pre>
	boolean -> "Z"
	byte -> "B"
	char -> "C"
	double -> "D"
	float -> "F"
	int -> "I"
	long -> "J"
	short -> "S"
	void -> "V"
	arrays -> "[" + type-encoding of component type
	object -> "L"
	+ fully qualified class name with "."'s replaced by "/"'s
	+ ";"</pre>
	*/
	public static String getEncodingOfClass( Class clazz )
	{
	if( clazz.isPrimitive() )
	{
	if( clazz == Boolean.TYPE )
	return "Z";
	if( clazz == Byte.TYPE )
	return "B";
	if( clazz == Character.TYPE )
	return "C";
	if( clazz == Double.TYPE )
	return "D";
	if( clazz == Float.TYPE )
	return "F";
	if( clazz == Integer.TYPE )
	return "I";
	if( clazz == Long.TYPE )
	return "J";
	if( clazz == Short.TYPE )
	return "S";
	if( clazz == Void.TYPE )
	return "V";
	else
	throw new RuntimeException( "Unknown primitive class " + clazz );
	}
	else if( clazz.isArray() )
	{
	return '[' + getEncodingOfClass( clazz.getComponentType() );
	}
	else
	{
	String classname = clazz.getName();
	int name_len = classname.length();
	char[] buf = new char[ name_len + 2 ];
	buf[0] = 'L';
	classname.getChars( 0, name_len, buf, 1 );

	int i;
	for( i=1; i <= name_len; i++ )
	{
	if( buf[i] == '.' )
	buf[i] = '/';
	}

	buf[i] = ';';
	return new String( buf );
	}
	}


	/**
	This function is the inverse of <code>getEncodingOfClass</code>.

	@see getEncodingOfClass

	@exception ClassNotFoundException If class encoded as type_code
	cannot be located.
	*/
	public static Class getClassForEncoding( String type_code )
	throws ClassNotFoundException
	{
	if( type_code.equals( "B" ) )
	return Byte.TYPE;
	if( type_code.equals( "C" ) )
	return Character.TYPE;
	if( type_code.equals( "D" ) )
	return Double.TYPE;
	if( type_code.equals( "F" ) )
	return Float.TYPE;
	if( type_code.equals( "I" ) )
	return Integer.TYPE;
	if( type_code.equals( "J" ) )
	return Long.TYPE;
	if( type_code.equals( "S" ) )
	return Short.TYPE;
	if( type_code.equals( "Z" ) )
	return Boolean.TYPE;
	if( type_code.charAt( 0 ) == 'L' )
	{
	return Class.forName(
	type_code.substring( 1, type_code.length() - 1 ).replace( '/', '.' ));
	}
	if( type_code.charAt( 0 ) == '[' )
	{
	int last_bracket = type_code.lastIndexOf( '[' );
	String brackets = type_code.substring( 0, last_bracket + 1 );
	String component = type_code.substring( last_bracket + 1 );

	// ??? This is what the Classpath implementation did, but I don't
	// think that it's correct. The JLS says that Class.forName takes the
	// classname of an array element in fully qualified form, whereas this
	// code is tring to strip off the punctuation.

	// if( component.charAt( 0 ) == 'L' )
	// component =
	// component.substring( 1, component.length() - 1 ).replace('/', '.');

	if( component.charAt( 0 ) == 'L' )
	component = component.replace('/', '.');

	return Class.forName( brackets + component );
	}
	else
	throw new ClassNotFoundException( "Type code cannot be parsed as a valid class name" );
	}


	/**
	Returns a <code>String</code> representing the type-encoding of
	M. The type-encoding of a method is:

	"(" + type-encodings of parameter types + ")"
	+ type-encoding of return type
	*/
	public static String getEncodingOfMethod( Method m )
	{
	String returnEncoding = getEncodingOfClass( m.getReturnType() );
	Class[] paramTypes = m.getParameterTypes();
	String[] paramEncodings = new String[ paramTypes.length ];

	String paramEncoding;
	int size = 2; // make room for parens
	for( int i=0; i < paramTypes.length; i++ )
	{
	paramEncoding = getEncodingOfClass( paramTypes[i] );
	size += paramEncoding.length();
	paramEncodings[i] = paramEncoding;
	}

	size += returnEncoding.length();

	StringBuffer buf = new StringBuffer( size );
	buf.append( '(' );

	for( int i=0; i < paramTypes.length; i++ )
	{
	buf.append( paramEncodings[i] );
	}

	buf.append( ')' );
	buf.append( returnEncoding );

	return buf.toString();
	}


	/**
	Returns a <code>String</code> representing the type-encoding of
	C. The type-encoding of a method is:

	"(" + type-encodings of parameter types + ")V"
	*/
	public static String getEncodingOfConstructor( Constructor c )
	{
	Class[] paramTypes = c.getParameterTypes();
	String[] paramEncodings = new String[ paramTypes.length ];

	String paramEncoding;
	int size = 3; // make room for parens and V for return type
	for( int i=0; i < paramTypes.length; i++ )
	{
	paramEncoding = getEncodingOfClass( paramTypes[i] );
	size += paramEncoding.length();
	paramEncodings[i] = paramEncoding;
	}

	StringBuffer buf = new StringBuffer( size );
	buf.append( '(' );

	for( int i=0; i < paramTypes.length; i++ )
	{
	buf.append( paramEncodings[i] );
	}

	buf.append( ")V" );

	return buf.toString();
	}


	/**
	Returns a <code>String</code> representing the type-encoding of
	MEM. <code>Constructor</code>s are handled by
	<code>getEncodingOfConstructor</code>. <code>Method</code>s are
	handled by <code>getEncodingOfMethod</code>. <code>Field</code>s
	are handled by returning the encoding of the type of the
	<code>Field</code>.
	*/
	public static String getEncodingOfMember( Member mem )
	{
	if( mem instanceof Constructor )
	return getEncodingOfConstructor( (Constructor)mem );
	if( mem instanceof Method )
	return getEncodingOfMethod( (Method)mem );
	else // Field
	return getEncodingOfClass( ((Field)mem).getType() );
	}
	}