emul/src/main/java/java/lang/reflect/Array.java
author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Fri, 18 Jan 2013 12:07:11 +0100
branchjdk7-b147
changeset 475 1a61b103ac45
child 477 22e99afe5083
permissions -rw-r--r--
Will replace direct manipulation with arrays with calls to java.lang.reflect.Array
     1 /*
     2  * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    25 
    26 package java.lang.reflect;
    27 
    28 /**
    29  * The {@code Array} class provides static methods to dynamically create and
    30  * access Java arrays.
    31  *
    32  * <p>{@code Array} permits widening conversions to occur during a get or set
    33  * operation, but throws an {@code IllegalArgumentException} if a narrowing
    34  * conversion would occur.
    35  *
    36  * @author Nakul Saraiya
    37  */
    38 public final
    39 class Array {
    40 
    41     /**
    42      * Constructor.  Class Array is not instantiable.
    43      */
    44     private Array() {}
    45 
    46     /**
    47      * Creates a new array with the specified component type and
    48      * length.
    49      * Invoking this method is equivalent to creating an array
    50      * as follows:
    51      * <blockquote>
    52      * <pre>
    53      * int[] x = {length};
    54      * Array.newInstance(componentType, x);
    55      * </pre>
    56      * </blockquote>
    57      *
    58      * @param componentType the {@code Class} object representing the
    59      * component type of the new array
    60      * @param length the length of the new array
    61      * @return the new array
    62      * @exception NullPointerException if the specified
    63      * {@code componentType} parameter is null
    64      * @exception IllegalArgumentException if componentType is {@link Void#TYPE}
    65      * @exception NegativeArraySizeException if the specified {@code length}
    66      * is negative
    67      */
    68     public static Object newInstance(Class<?> componentType, int length)
    69         throws NegativeArraySizeException {
    70         return newArray(componentType, length);
    71     }
    72 
    73     /**
    74      * Creates a new array
    75      * with the specified component type and dimensions.
    76      * If {@code componentType}
    77      * represents a non-array class or interface, the new array
    78      * has {@code dimensions.length} dimensions and
    79      * {@code componentType} as its component type. If
    80      * {@code componentType} represents an array class, the
    81      * number of dimensions of the new array is equal to the sum
    82      * of {@code dimensions.length} and the number of
    83      * dimensions of {@code componentType}. In this case, the
    84      * component type of the new array is the component type of
    85      * {@code componentType}.
    86      *
    87      * <p>The number of dimensions of the new array must not
    88      * exceed the number of array dimensions supported by the
    89      * implementation (typically 255).
    90      *
    91      * @param componentType the {@code Class} object representing the component
    92      * type of the new array
    93      * @param dimensions an array of {@code int} representing the dimensions of
    94      * the new array
    95      * @return the new array
    96      * @exception NullPointerException if the specified
    97      * {@code componentType} argument is null
    98      * @exception IllegalArgumentException if the specified {@code dimensions}
    99      * argument is a zero-dimensional array, or if the number of
   100      * requested dimensions exceeds the limit on the number of array dimensions
   101      * supported by the implementation (typically 255), or if componentType
   102      * is {@link Void#TYPE}.
   103      * @exception NegativeArraySizeException if any of the components in
   104      * the specified {@code dimensions} argument is negative.
   105      */
   106     public static Object newInstance(Class<?> componentType, int... dimensions)
   107         throws IllegalArgumentException, NegativeArraySizeException {
   108         return multiNewArray(componentType, dimensions);
   109     }
   110 
   111     /**
   112      * Returns the length of the specified array object, as an {@code int}.
   113      *
   114      * @param array the array
   115      * @return the length of the array
   116      * @exception IllegalArgumentException if the object argument is not
   117      * an array
   118      */
   119     public static native int getLength(Object array)
   120         throws IllegalArgumentException;
   121 
   122     /**
   123      * Returns the value of the indexed component in the specified
   124      * array object.  The value is automatically wrapped in an object
   125      * if it has a primitive type.
   126      *
   127      * @param array the array
   128      * @param index the index
   129      * @return the (possibly wrapped) value of the indexed component in
   130      * the specified array
   131      * @exception NullPointerException If the specified object is null
   132      * @exception IllegalArgumentException If the specified object is not
   133      * an array
   134      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   135      * argument is negative, or if it is greater than or equal to the
   136      * length of the specified array
   137      */
   138     public static native Object get(Object array, int index)
   139         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   140 
   141     /**
   142      * Returns the value of the indexed component in the specified
   143      * array object, as a {@code boolean}.
   144      *
   145      * @param array the array
   146      * @param index the index
   147      * @return the value of the indexed component in the specified array
   148      * @exception NullPointerException If the specified object is null
   149      * @exception IllegalArgumentException If the specified object is not
   150      * an array, or if the indexed element cannot be converted to the
   151      * return type by an identity or widening conversion
   152      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   153      * argument is negative, or if it is greater than or equal to the
   154      * length of the specified array
   155      * @see Array#get
   156      */
   157     public static native boolean getBoolean(Object array, int index)
   158         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   159 
   160     /**
   161      * Returns the value of the indexed component in the specified
   162      * array object, as a {@code byte}.
   163      *
   164      * @param array the array
   165      * @param index the index
   166      * @return the value of the indexed component in the specified array
   167      * @exception NullPointerException If the specified object is null
   168      * @exception IllegalArgumentException If the specified object is not
   169      * an array, or if the indexed element cannot be converted to the
   170      * return type by an identity or widening conversion
   171      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   172      * argument is negative, or if it is greater than or equal to the
   173      * length of the specified array
   174      * @see Array#get
   175      */
   176     public static native byte getByte(Object array, int index)
   177         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   178 
   179     /**
   180      * Returns the value of the indexed component in the specified
   181      * array object, as a {@code char}.
   182      *
   183      * @param array the array
   184      * @param index the index
   185      * @return the value of the indexed component in the specified array
   186      * @exception NullPointerException If the specified object is null
   187      * @exception IllegalArgumentException If the specified object is not
   188      * an array, or if the indexed element cannot be converted to the
   189      * return type by an identity or widening conversion
   190      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   191      * argument is negative, or if it is greater than or equal to the
   192      * length of the specified array
   193      * @see Array#get
   194      */
   195     public static native char getChar(Object array, int index)
   196         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   197 
   198     /**
   199      * Returns the value of the indexed component in the specified
   200      * array object, as a {@code short}.
   201      *
   202      * @param array the array
   203      * @param index the index
   204      * @return the value of the indexed component in the specified array
   205      * @exception NullPointerException If the specified object is null
   206      * @exception IllegalArgumentException If the specified object is not
   207      * an array, or if the indexed element cannot be converted to the
   208      * return type by an identity or widening conversion
   209      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   210      * argument is negative, or if it is greater than or equal to the
   211      * length of the specified array
   212      * @see Array#get
   213      */
   214     public static native short getShort(Object array, int index)
   215         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   216 
   217     /**
   218      * Returns the value of the indexed component in the specified
   219      * array object, as an {@code int}.
   220      *
   221      * @param array the array
   222      * @param index the index
   223      * @return the value of the indexed component in the specified array
   224      * @exception NullPointerException If the specified object is null
   225      * @exception IllegalArgumentException If the specified object is not
   226      * an array, or if the indexed element cannot be converted to the
   227      * return type by an identity or widening conversion
   228      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   229      * argument is negative, or if it is greater than or equal to the
   230      * length of the specified array
   231      * @see Array#get
   232      */
   233     public static native int getInt(Object array, int index)
   234         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   235 
   236     /**
   237      * Returns the value of the indexed component in the specified
   238      * array object, as a {@code long}.
   239      *
   240      * @param array the array
   241      * @param index the index
   242      * @return the value of the indexed component in the specified array
   243      * @exception NullPointerException If the specified object is null
   244      * @exception IllegalArgumentException If the specified object is not
   245      * an array, or if the indexed element cannot be converted to the
   246      * return type by an identity or widening conversion
   247      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   248      * argument is negative, or if it is greater than or equal to the
   249      * length of the specified array
   250      * @see Array#get
   251      */
   252     public static native long getLong(Object array, int index)
   253         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   254 
   255     /**
   256      * Returns the value of the indexed component in the specified
   257      * array object, as a {@code float}.
   258      *
   259      * @param array the array
   260      * @param index the index
   261      * @return the value of the indexed component in the specified array
   262      * @exception NullPointerException If the specified object is null
   263      * @exception IllegalArgumentException If the specified object is not
   264      * an array, or if the indexed element cannot be converted to the
   265      * return type by an identity or widening conversion
   266      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   267      * argument is negative, or if it is greater than or equal to the
   268      * length of the specified array
   269      * @see Array#get
   270      */
   271     public static native float getFloat(Object array, int index)
   272         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   273 
   274     /**
   275      * Returns the value of the indexed component in the specified
   276      * array object, as a {@code double}.
   277      *
   278      * @param array the array
   279      * @param index the index
   280      * @return the value of the indexed component in the specified array
   281      * @exception NullPointerException If the specified object is null
   282      * @exception IllegalArgumentException If the specified object is not
   283      * an array, or if the indexed element cannot be converted to the
   284      * return type by an identity or widening conversion
   285      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   286      * argument is negative, or if it is greater than or equal to the
   287      * length of the specified array
   288      * @see Array#get
   289      */
   290     public static native double getDouble(Object array, int index)
   291         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   292 
   293     /**
   294      * Sets the value of the indexed component of the specified array
   295      * object to the specified new value.  The new value is first
   296      * automatically unwrapped if the array has a primitive component
   297      * type.
   298      * @param array the array
   299      * @param index the index into the array
   300      * @param value the new value of the indexed component
   301      * @exception NullPointerException If the specified object argument
   302      * is null
   303      * @exception IllegalArgumentException If the specified object argument
   304      * is not an array, or if the array component type is primitive and
   305      * an unwrapping conversion fails
   306      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   307      * argument is negative, or if it is greater than or equal to
   308      * the length of the specified array
   309      */
   310     public static native void set(Object array, int index, Object value)
   311         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   312 
   313     /**
   314      * Sets the value of the indexed component of the specified array
   315      * object to the specified {@code boolean} value.
   316      * @param array the array
   317      * @param index the index into the array
   318      * @param z the new value of the indexed component
   319      * @exception NullPointerException If the specified object argument
   320      * is null
   321      * @exception IllegalArgumentException If the specified object argument
   322      * is not an array, or if the specified value cannot be converted
   323      * to the underlying array's component type by an identity or a
   324      * primitive widening conversion
   325      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   326      * argument is negative, or if it is greater than or equal to
   327      * the length of the specified array
   328      * @see Array#set
   329      */
   330     public static native void setBoolean(Object array, int index, boolean z)
   331         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   332 
   333     /**
   334      * Sets the value of the indexed component of the specified array
   335      * object to the specified {@code byte} value.
   336      * @param array the array
   337      * @param index the index into the array
   338      * @param b the new value of the indexed component
   339      * @exception NullPointerException If the specified object argument
   340      * is null
   341      * @exception IllegalArgumentException If the specified object argument
   342      * is not an array, or if the specified value cannot be converted
   343      * to the underlying array's component type by an identity or a
   344      * primitive widening conversion
   345      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   346      * argument is negative, or if it is greater than or equal to
   347      * the length of the specified array
   348      * @see Array#set
   349      */
   350     public static native void setByte(Object array, int index, byte b)
   351         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   352 
   353     /**
   354      * Sets the value of the indexed component of the specified array
   355      * object to the specified {@code char} value.
   356      * @param array the array
   357      * @param index the index into the array
   358      * @param c the new value of the indexed component
   359      * @exception NullPointerException If the specified object argument
   360      * is null
   361      * @exception IllegalArgumentException If the specified object argument
   362      * is not an array, or if the specified value cannot be converted
   363      * to the underlying array's component type by an identity or a
   364      * primitive widening conversion
   365      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   366      * argument is negative, or if it is greater than or equal to
   367      * the length of the specified array
   368      * @see Array#set
   369      */
   370     public static native void setChar(Object array, int index, char c)
   371         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   372 
   373     /**
   374      * Sets the value of the indexed component of the specified array
   375      * object to the specified {@code short} value.
   376      * @param array the array
   377      * @param index the index into the array
   378      * @param s the new value of the indexed component
   379      * @exception NullPointerException If the specified object argument
   380      * is null
   381      * @exception IllegalArgumentException If the specified object argument
   382      * is not an array, or if the specified value cannot be converted
   383      * to the underlying array's component type by an identity or a
   384      * primitive widening conversion
   385      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   386      * argument is negative, or if it is greater than or equal to
   387      * the length of the specified array
   388      * @see Array#set
   389      */
   390     public static native void setShort(Object array, int index, short s)
   391         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   392 
   393     /**
   394      * Sets the value of the indexed component of the specified array
   395      * object to the specified {@code int} value.
   396      * @param array the array
   397      * @param index the index into the array
   398      * @param i the new value of the indexed component
   399      * @exception NullPointerException If the specified object argument
   400      * is null
   401      * @exception IllegalArgumentException If the specified object argument
   402      * is not an array, or if the specified value cannot be converted
   403      * to the underlying array's component type by an identity or a
   404      * primitive widening conversion
   405      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   406      * argument is negative, or if it is greater than or equal to
   407      * the length of the specified array
   408      * @see Array#set
   409      */
   410     public static native void setInt(Object array, int index, int i)
   411         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   412 
   413     /**
   414      * Sets the value of the indexed component of the specified array
   415      * object to the specified {@code long} value.
   416      * @param array the array
   417      * @param index the index into the array
   418      * @param l the new value of the indexed component
   419      * @exception NullPointerException If the specified object argument
   420      * is null
   421      * @exception IllegalArgumentException If the specified object argument
   422      * is not an array, or if the specified value cannot be converted
   423      * to the underlying array's component type by an identity or a
   424      * primitive widening conversion
   425      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   426      * argument is negative, or if it is greater than or equal to
   427      * the length of the specified array
   428      * @see Array#set
   429      */
   430     public static native void setLong(Object array, int index, long l)
   431         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   432 
   433     /**
   434      * Sets the value of the indexed component of the specified array
   435      * object to the specified {@code float} value.
   436      * @param array the array
   437      * @param index the index into the array
   438      * @param f the new value of the indexed component
   439      * @exception NullPointerException If the specified object argument
   440      * is null
   441      * @exception IllegalArgumentException If the specified object argument
   442      * is not an array, or if the specified value cannot be converted
   443      * to the underlying array's component type by an identity or a
   444      * primitive widening conversion
   445      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   446      * argument is negative, or if it is greater than or equal to
   447      * the length of the specified array
   448      * @see Array#set
   449      */
   450     public static native void setFloat(Object array, int index, float f)
   451         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   452 
   453     /**
   454      * Sets the value of the indexed component of the specified array
   455      * object to the specified {@code double} value.
   456      * @param array the array
   457      * @param index the index into the array
   458      * @param d the new value of the indexed component
   459      * @exception NullPointerException If the specified object argument
   460      * is null
   461      * @exception IllegalArgumentException If the specified object argument
   462      * is not an array, or if the specified value cannot be converted
   463      * to the underlying array's component type by an identity or a
   464      * primitive widening conversion
   465      * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
   466      * argument is negative, or if it is greater than or equal to
   467      * the length of the specified array
   468      * @see Array#set
   469      */
   470     public static native void setDouble(Object array, int index, double d)
   471         throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
   472 
   473     /*
   474      * Private
   475      */
   476 
   477     private static native Object newArray(Class componentType, int length)
   478         throws NegativeArraySizeException;
   479 
   480     private static native Object multiNewArray(Class componentType,
   481         int[] dimensions)
   482         throws IllegalArgumentException, NegativeArraySizeException;
   483 
   484 
   485 }