type.java

开源的java 编辑器源代码

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (C) 2000 INRIA, France Telecom
 * Copyright (C) 2002 France Telecom
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact: [e-mail]
 *
 * Author: Eric Bruneton
 */

package org.objectweb.asm;

import java.lang.reflect.Method;

/**
 * A Java type. This class can be used to make it easier to manipulate type
 * and method descriptors.
 */

public class Type {

  /**
   * The sort of the <tt>void</tt> type. See {@link #getSort getSort}.
   */

  public final static int VOID = 0;

  /**
   * The sort of the <tt>boolean</tt> type. See {@link #getSort getSort}.
   */

  public final static int BOOLEAN = 1;

  /**
   * The sort of the <tt>char</tt> type. See {@link #getSort getSort}.
   */

  public final static int CHAR = 2;

  /**
   * The sort of the <tt>byte</tt> type. See {@link #getSort getSort}.
   */

  public final static int BYTE = 3;

  /**
   * The sort of the <tt>short</tt> type. See {@link #getSort getSort}.
   */

  public final static int SHORT = 4;

  /**
   * The sort of the <tt>int</tt> type. See {@link #getSort getSort}.
   */

  public final static int INT = 5;

  /**
   * The sort of the <tt>float</tt> type. See {@link #getSort getSort}.
   */

  public final static int FLOAT = 6;

  /**
   * The sort of the <tt>long</tt> type. See {@link #getSort getSort}.
   */

  public final static int LONG = 7;

  /**
   * The sort of the <tt>double</tt> type. See {@link #getSort getSort}.
   */

  public final static int DOUBLE = 8;

  /**
   * The sort of array reference types. See {@link #getSort getSort}.
   */

  public final static int ARRAY = 9;

  /**
   * The sort of object reference type. See {@link #getSort getSort}.
   */

  public final static int OBJECT = 10;

  /**
   * The <tt>void</tt> type.
   */

  public final static Type VOID_TYPE = new Type(VOID);

  /**
   * The <tt>boolean</tt> type.
   */

  public final static Type BOOLEAN_TYPE = new Type(BOOLEAN);

  /**
   * The <tt>char</tt> type.
   */

  public final static Type CHAR_TYPE = new Type(CHAR);

  /**
   * The <tt>byte</tt> type.
   */

  public final static Type BYTE_TYPE = new Type(BYTE);

  /**
   * The <tt>short</tt> type.
   */

  public final static Type SHORT_TYPE = new Type(SHORT);

  /**
   * The <tt>int</tt> type.
   */

  public final static Type INT_TYPE = new Type(INT);

  /**
   * The <tt>float</tt> type.
   */

  public final static Type FLOAT_TYPE = new Type(FLOAT);

  /**
   * The <tt>long</tt> type.
   */

  public final static Type LONG_TYPE = new Type(LONG);

  /**
   * The <tt>double</tt> type.
   */

  public final static Type DOUBLE_TYPE = new Type(DOUBLE);

  // --------------------------------------------------------------------------
  // Fields
  // --------------------------------------------------------------------------

  /**
   * The sort of this Java type.
   */

  private final int sort;

  /**
   * A buffer containing the descriptor of this Java type.
   * This field is only used for reference types.
   */

  private char[] buf;

  /**
   * The offset of the descriptor of this Java type in {@link #buf buf}.
   * This field is only used for reference types.
   */

  private int off;

  /**
   * The length of the descriptor of this Java type.
   */

  private int len;

  // --------------------------------------------------------------------------
  // Constructors
  // --------------------------------------------------------------------------

  /**
   * Constructs a primitive type.
   *
   * @param sort the sort of the primitive type to be constructed.
   */

  private Type (final int sort) {
    this.sort = sort;
    this.len = 1;
  }

  /**
   * Constructs a reference type.
   *
   * @param sort the sort of the reference type to be constructed.
   * @param buf a buffer containing the descriptor of the previous type.
   * @param off the offset of this descriptor in the previous buffer.
   * @param len the length of this descriptor.
   */

  private Type (
    final int sort,
    final char[] buf,
    final int off,
    final int len)
  {
    this.sort = sort;
    this.buf = buf;
    this.off = off;
    this.len = len;
  }

  /**
   * Returns the Java type corresponding to the given type descriptor.
   *
   * @param typeDescriptor a type descriptor.
   * @return the Java type corresponding to the given type descriptor.
   */

  public static Type getType (final String typeDescriptor) {
    return getType(typeDescriptor.toCharArray(), 0);
  }

  /**
   * Returns the Java type corresponding to the given class.
   *
   * @param c a class.
   * @return the Java type corresponding to the given class.
   */

  public static Type getType (final Class c) {
    if (c.isPrimitive()) {
      if (c == Integer.TYPE) {
        return INT_TYPE;
      } else if (c == Void.TYPE) {
        return VOID_TYPE;
      } else if (c == Boolean.TYPE) {
        return BOOLEAN_TYPE;
      } else if (c == Byte.TYPE) {
        return BYTE_TYPE;
      } else if (c == Character.TYPE) {
        return CHAR_TYPE;
      } else if (c == Short.TYPE) {
        return SHORT_TYPE;
      } else if (c == Double.TYPE) {
        return DOUBLE_TYPE;
      } else if (c == Float.TYPE) {
        return FLOAT_TYPE;
      } else /*if (c == Long.TYPE)*/ {
        return LONG_TYPE;
      }
    } else {
      return getType(getDescriptor(c));
    }
  }

  /**
   * Returns the Java types corresponding to the argument types of the given
   * method descriptor.
   *
   * @param methodDescriptor a method descriptor.
   * @return the Java types corresponding to the argument types of the given
   *      method descriptor.
   */

  public static Type[] getArgumentTypes (final String methodDescriptor) {
    char[] buf = methodDescriptor.toCharArray();
    int off = 1;
    int size = 0;
    while (true) {
      char car = buf[off++];
      if (car == ')') {
        break;
      } else if (car == 'L') {
        while (buf[off++] != ';') {
        }
        ++size;
      } else if (car != '[') {
        ++size;
      }
    }
    Type[] args = new Type[size];
    off = 1;
    size = 0;
    while (buf[off] != ')') {
      args[size] = getType(buf, off);
      off += args[size].len;
      size += 1;
    }
    return args;
  }

  /**
   * Returns the Java types corresponding to the argument types of the given
   * method.
   *
   * @param method a method.
   * @return the Java types corresponding to the argument types of the given
   *      method.
   */

  public static Type[] getArgumentTypes (final Method method) {
    Class[] classes = method.getParameterTypes();
    Type[] types = new Type[classes.length];
    for (int i = classes.length - 1; i >= 0; --i) {
      types[i] = getType(classes[i]);
    }
    return types;
  }

  /**
   * Returns the Java type corresponding to the return type of the given
   * method descriptor.
   *
   * @param methodDescriptor a method descriptor.
   * @return the Java type corresponding to the return type of the given
   *      method descriptor.
   */

  public static Type getReturnType (final String methodDescriptor) {
    char[] buf = methodDescriptor.toCharArray();
    return getType(buf, methodDescriptor.indexOf(')') + 1);
  }

  /**
   * Returns the Java type corresponding to the return type of the given
   * method.
   *
   * @param method a method.
   * @return the Java type corresponding to the return type of the given
   *      method.
   */

  public static Type getReturnType (final Method method) {
    return getType(method.getReturnType());
  }

  /**