1 /*

     2  * Copyright (c) 2000, 2013, 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 

    27 package javax.management.openmbean;

    28 

    29 

    30 // java import

    31 //

    32 import java.util.Set;

    33 import javax.management.Descriptor;

    34 import javax.management.DescriptorRead;  // for Javadoc

    35 import javax.management.ImmutableDescriptor;

    36 import javax.management.MBeanParameterInfo;

    37 

    38 // OpenMBeanAttributeInfoSupport and this class are very similar

    39 // but can't easily be refactored because there's no multiple inheritance.

    40 // The best we can do for refactoring is to put a bunch of static methods

    41 // in OpenMBeanAttributeInfoSupport and import them here.

    42 import static javax.management.openmbean.OpenMBeanAttributeInfoSupport.*;

    43 

    44 /**

    45  * Describes a parameter used in one or more operations or

    46  * constructors of an open MBean.

    47  *

    48  *

    49  * @since 1.5

    50  */

    51 public class OpenMBeanParameterInfoSupport

    52     extends MBeanParameterInfo

    53     implements OpenMBeanParameterInfo {

    54 

    55     /* Serial version */

    56     static final long serialVersionUID = -7235016873758443122L;

    57 

    58     /**

    59      * @serial The open mbean parameter's <i>open type</i>

    60      */

    61     private OpenType<?>    openType;

    62 

    63     /**

    64      * @serial The open mbean parameter's default value

    65      */

    66     private Object      defaultValue    = null;

    67 

    68     /**

    69      * @serial The open mbean parameter's legal values. This {@link

    70      * Set} is unmodifiable

    71      */

    72     private Set<?> legalValues     = null;  // to be constructed unmodifiable

    73 

    74     /**

    75      * @serial The open mbean parameter's min value

    76      */

    77     private Comparable<?> minValue        = null;

    78 

    79     /**

    80      * @serial The open mbean parameter's max value

    81      */

    82     private Comparable<?> maxValue        = null;

    83 

    84 

    85     // As this instance is immutable, these two values need only

    86     // be calculated once.

    87     private transient Integer myHashCode = null;        // As this instance is immutable, these two values

    88     private transient String  myToString = null;        // need only be calculated once.

    89 

    90 

    91     /**

    92      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,

    93      * which describes the parameter used in one or more operations or

    94      * constructors of a class of open MBeans, with the specified

    95      * {@code name}, {@code openType} and {@code description}.

    96      *

    97      * @param name  cannot be a null or empty string.

    98      *

    99      * @param description  cannot be a null or empty string.

   100      *

   101      * @param openType  cannot be null.

   102      *

   103      * @throws IllegalArgumentException if {@code name} or {@code

   104      * description} are null or empty string, or {@code openType} is

   105      * null.

   106      */

   107     public OpenMBeanParameterInfoSupport(String name,

   108                                          String description,

   109                                          OpenType<?> openType) {

   110         this(name, description, openType, (Descriptor) null);

   111     }

   112 

   113     /**

   114      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,

   115      * which describes the parameter used in one or more operations or

   116      * constructors of a class of open MBeans, with the specified

   117      * {@code name}, {@code openType}, {@code description},

   118      * and {@code descriptor}.

   119      *

   120      * <p>The {@code descriptor} can contain entries that will define

   121      * the values returned by certain methods of this class, as

   122      * explained in the <a href="package-summary.html#constraints">

   123      * package description</a>.

   124      *

   125      * @param name  cannot be a null or empty string.

   126      *

   127      * @param description  cannot be a null or empty string.

   128      *

   129      * @param openType  cannot be null.

   130      *

   131      * @param descriptor The descriptor for the parameter.  This may be null

   132      * which is equivalent to an empty descriptor.

   133      *

   134      * @throws IllegalArgumentException if {@code name} or {@code

   135      * description} are null or empty string, or {@code openType} is

   136      * null, or the descriptor entries are invalid as described in the

   137      * <a href="package-summary.html#constraints">package

   138      * description</a>.

   139      *

   140      * @since 1.6

   141      */

   142     public OpenMBeanParameterInfoSupport(String name,

   143                                          String description,

   144                                          OpenType<?> openType,

   145                                          Descriptor descriptor) {

   146 

   147 

   148         // Construct parent's state

   149         //

   150         super(name,

   151               (openType==null) ? null : openType.getClassName(),

   152               description,

   153               ImmutableDescriptor.union(descriptor,(openType==null)?null:

   154                 openType.getDescriptor()));

   155 

   156         // Initialize this instance's specific state

   157         //

   158         this.openType = openType;

   159 

   160         descriptor = getDescriptor();  // replace null by empty

   161         this.defaultValue = valueFrom(descriptor, "defaultValue", openType);

   162         this.legalValues = valuesFrom(descriptor, "legalValues", openType);

   163         this.minValue = comparableValueFrom(descriptor, "minValue", openType);

   164         this.maxValue = comparableValueFrom(descriptor, "maxValue", openType);

   165 

   166         try {

   167             check(this);

   168         } catch (OpenDataException e) {

   169             throw new IllegalArgumentException(e.getMessage(), e);

   170         }

   171     }

   172 

   173 

   174     /**

   175      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,

   176      * which describes the parameter used in one or more operations or

   177      * constructors of a class of open MBeans, with the specified

   178      * {@code name}, {@code openType}, {@code description} and {@code

   179      * defaultValue}.

   180      *

   181      * @param name  cannot be a null or empty string.

   182      *

   183      * @param description  cannot be a null or empty string.

   184      *

   185      * @param openType  cannot be null.

   186      *

   187      * @param defaultValue must be a valid value for the {@code

   188      * openType} specified for this parameter; default value not

   189      * supported for {@code ArrayType} and {@code TabularType}; can be

   190      * null, in which case it means that no default value is set.

   191      *

   192      * @param <T> allows the compiler to check that the {@code defaultValue},

   193      * if non-null, has the correct Java type for the given {@code openType}.

   194      *

   195      * @throws IllegalArgumentException if {@code name} or {@code

   196      * description} are null or empty string, or {@code openType} is

   197      * null.

   198      *

   199      * @throws OpenDataException if {@code defaultValue} is not a

   200      * valid value for the specified {@code openType}, or {@code

   201      * defaultValue} is non null and {@code openType} is an {@code

   202      * ArrayType} or a {@code TabularType}.

   203      */

   204     public <T> OpenMBeanParameterInfoSupport(String   name,

   205                                              String   description,

   206                                              OpenType<T> openType,

   207                                              T        defaultValue)

   208             throws OpenDataException {

   209         this(name, description, openType, defaultValue, (T[]) null);

   210     }

   211 

   212     /**

   213      * <p>Constructs an {@code OpenMBeanParameterInfoSupport} instance,

   214      * which describes the parameter used in one or more operations or

   215      * constructors of a class of open MBeans, with the specified

   216      * {@code name}, {@code openType}, {@code description}, {@code

   217      * defaultValue} and {@code legalValues}.</p>

   218      *

   219      * <p>The contents of {@code legalValues} are copied, so subsequent

   220      * modifications of the array referenced by {@code legalValues}

   221      * have no impact on this {@code OpenMBeanParameterInfoSupport}

   222      * instance.</p>

   223      *

   224      * @param name  cannot be a null or empty string.

   225      *

   226      * @param description  cannot be a null or empty string.

   227      *

   228      * @param openType  cannot be null.

   229      *

   230      * @param defaultValue must be a valid value for the {@code

   231      * openType} specified for this parameter; default value not

   232      * supported for {@code ArrayType} and {@code TabularType}; can be

   233      * null, in which case it means that no default value is set.

   234      *

   235      * @param legalValues each contained value must be valid for the

   236      * {@code openType} specified for this parameter; legal values not

   237      * supported for {@code ArrayType} and {@code TabularType}; can be

   238      * null or empty.

   239      *

   240      * @param <T> allows the compiler to check that the {@code

   241      * defaultValue} and {@code legalValues}, if non-null, have the

   242      * correct Java type for the given {@code openType}.

   243      *

   244      * @throws IllegalArgumentException if {@code name} or {@code

   245      * description} are null or empty string, or {@code openType} is

   246      * null.

   247      *

   248      * @throws OpenDataException if {@code defaultValue} is not a

   249      * valid value for the specified {@code openType}, or one value in

   250      * {@code legalValues} is not valid for the specified {@code

   251      * openType}, or {@code defaultValue} is non null and {@code

   252      * openType} is an {@code ArrayType} or a {@code TabularType}, or

   253      * {@code legalValues} is non null and non empty and {@code

   254      * openType} is an {@code ArrayType} or a {@code TabularType}, or

   255      * {@code legalValues} is non null and non empty and {@code

   256      * defaultValue} is not contained in {@code legalValues}.

   257      */

   258     public <T> OpenMBeanParameterInfoSupport(String   name,

   259                                              String   description,

   260                                              OpenType<T> openType,

   261                                              T        defaultValue,

   262                                              T[]      legalValues)

   263             throws OpenDataException {

   264         this(name, description, openType,

   265              defaultValue, legalValues, null, null);

   266     }

   267 

   268 

   269     /**

   270      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,

   271      * which describes the parameter used in one or more operations or

   272      * constructors of a class of open MBeans, with the specified

   273      * {@code name}, {@code openType}, {@code description}, {@code

   274      * defaultValue}, {@code minValue} and {@code maxValue}.

   275      *

   276      * It is possible to specify minimal and maximal values only for

   277      * an open type whose values are {@code Comparable}.

   278      *

   279      * @param name  cannot be a null or empty string.

   280      *

   281      * @param description  cannot be a null or empty string.

   282      *

   283      * @param openType  cannot be null.

   284      *

   285      * @param defaultValue must be a valid value for the {@code

   286      * openType} specified for this parameter; default value not

   287      * supported for {@code ArrayType} and {@code TabularType}; can be

   288      * null, in which case it means that no default value is set.

   289      *

   290      * @param minValue must be valid for the {@code openType}

   291      * specified for this parameter; can be null, in which case it

   292      * means that no minimal value is set.

   293      *

   294      * @param maxValue must be valid for the {@code openType}

   295      * specified for this parameter; can be null, in which case it

   296      * means that no maximal value is set.

   297      *

   298      * @param <T> allows the compiler to check that the {@code

   299      * defaultValue}, {@code minValue}, and {@code maxValue}, if

   300      * non-null, have the correct Java type for the given {@code

   301      * openType}.

   302      *

   303      * @throws IllegalArgumentException if {@code name} or {@code

   304      * description} are null or empty string, or {@code openType} is

   305      * null.

   306      *

   307      * @throws OpenDataException if {@code defaultValue}, {@code

   308      * minValue} or {@code maxValue} is not a valid value for the

   309      * specified {@code openType}, or {@code defaultValue} is non null

   310      * and {@code openType} is an {@code ArrayType} or a {@code

   311      * TabularType}, or both {@code minValue} and {@code maxValue} are

   312      * non-null and {@code minValue.compareTo(maxValue) > 0} is {@code

   313      * true}, or both {@code defaultValue} and {@code minValue} are

   314      * non-null and {@code minValue.compareTo(defaultValue) > 0} is

   315      * {@code true}, or both {@code defaultValue} and {@code maxValue}

   316      * are non-null and {@code defaultValue.compareTo(maxValue) > 0}

   317      * is {@code true}.

   318      */

   319     public <T> OpenMBeanParameterInfoSupport(String     name,

   320                                              String     description,

   321                                              OpenType<T>   openType,

   322                                              T          defaultValue,

   323                                              Comparable<T> minValue,

   324                                              Comparable<T> maxValue)

   325             throws OpenDataException {

   326         this(name, description, openType,

   327              defaultValue, null, minValue, maxValue);

   328     }

   329 

   330     private <T> OpenMBeanParameterInfoSupport(String name,

   331                                               String description,

   332                                               OpenType<T> openType,

   333                                               T defaultValue,

   334                                               T[] legalValues,

   335                                               Comparable<T> minValue,

   336                                               Comparable<T> maxValue)

   337             throws OpenDataException {

   338         super(name,

   339               (openType == null) ? null : openType.getClassName(),

   340               description,

   341               makeDescriptor(openType,

   342                              defaultValue, legalValues, minValue, maxValue));

   343 

   344         this.openType = openType;

   345 

   346         Descriptor d = getDescriptor();

   347         this.defaultValue = defaultValue;

   348         this.minValue = minValue;

   349         this.maxValue = maxValue;

   350         // We already converted the array into an unmodifiable Set

   351         // in the descriptor.

   352         this.legalValues = (Set<?>) d.getFieldValue("legalValues");

   353 

   354         check(this);

   355     }

   356 

   357     /**

   358      * An object serialized in a version of the API before Descriptors were

   359      * added to this class will have an empty or null Descriptor.

   360      * For consistency with our

   361      * behavior in this version, we must replace the object with one

   362      * where the Descriptors reflect the same values of openType, defaultValue,

   363      * etc.

   364      **/

   365     private Object readResolve() {

   366         if (getDescriptor().getFieldNames().length == 0) {

   367             // This noise allows us to avoid "unchecked" warnings without

   368             // having to suppress them explicitly.

   369             OpenType<Object> xopenType = cast(openType);

   370             Set<Object> xlegalValues = cast(legalValues);

   371             Comparable<Object> xminValue = cast(minValue);

   372             Comparable<Object> xmaxValue = cast(maxValue);

   373             return new OpenMBeanParameterInfoSupport(

   374                     name, description, openType,

   375                     makeDescriptor(xopenType, defaultValue, xlegalValues,

   376                                    xminValue, xmaxValue));

   377         } else

   378             return this;

   379     }

   380 

   381     /**

   382      * Returns the open type for the values of the parameter described

   383      * by this {@code OpenMBeanParameterInfoSupport} instance.

   384      */

   385     public OpenType<?> getOpenType() {

   386         return openType;

   387     }

   388 

   389     /**

   390      * Returns the default value for the parameter described by this

   391      * {@code OpenMBeanParameterInfoSupport} instance, if specified,

   392      * or {@code null} otherwise.

   393      */

   394     public Object getDefaultValue() {

   395 

   396         // Special case for ArrayType and TabularType

   397         // [JF] TODO: clone it so that it cannot be altered,

   398         // [JF] TODO: if we decide to support defaultValue as an array itself.

   399         // [JF] As of today (oct 2000) it is not supported so

   400         // defaultValue is null for arrays. Nothing to do.

   401 

   402         return defaultValue;

   403     }

   404 

   405     /**

   406      * Returns an unmodifiable Set of legal values for the parameter

   407      * described by this {@code OpenMBeanParameterInfoSupport}

   408      * instance, if specified, or {@code null} otherwise.

   409      */

   410     public Set<?> getLegalValues() {

   411 

   412         // Special case for ArrayType and TabularType

   413         // [JF] TODO: clone values so that they cannot be altered,

   414         // [JF] TODO: if we decide to support LegalValues as an array itself.

   415         // [JF] As of today (oct 2000) it is not supported so

   416         // legalValues is null for arrays. Nothing to do.

   417 

   418         // Returns our legalValues Set (set was constructed unmodifiable)

   419         return (legalValues);

   420     }

   421 

   422     /**

   423      * Returns the minimal value for the parameter described by this

   424      * {@code OpenMBeanParameterInfoSupport} instance, if specified,

   425      * or {@code null} otherwise.

   426      */

   427     public Comparable<?> getMinValue() {

   428 

   429         // Note: only comparable values have a minValue, so that's not

   430         // the case of arrays and tabulars (always null).

   431 

   432         return minValue;

   433     }

   434 

   435     /**

   436      * Returns the maximal value for the parameter described by this

   437      * {@code OpenMBeanParameterInfoSupport} instance, if specified,

   438      * or {@code null} otherwise.

   439      */

   440     public Comparable<?> getMaxValue() {

   441 

   442         // Note: only comparable values have a maxValue, so that's not

   443         // the case of arrays and tabulars (always null).

   444 

   445         return maxValue;

   446     }

   447 

   448     /**

   449      * Returns {@code true} if this {@code

   450      * OpenMBeanParameterInfoSupport} instance specifies a non-null

   451      * default value for the described parameter, {@code false}

   452      * otherwise.

   453      */

   454     public boolean hasDefaultValue() {

   455 

   456         return (defaultValue != null);

   457     }

   458 

   459     /**

   460      * Returns {@code true} if this {@code

   461      * OpenMBeanParameterInfoSupport} instance specifies a non-null

   462      * set of legal values for the described parameter, {@code false}

   463      * otherwise.

   464      */

   465     public boolean hasLegalValues() {

   466 

   467         return (legalValues != null);

   468     }

   469 

   470     /**

   471      * Returns {@code true} if this {@code

   472      * OpenMBeanParameterInfoSupport} instance specifies a non-null

   473      * minimal value for the described parameter, {@code false}

   474      * otherwise.

   475      */

   476     public boolean hasMinValue() {

   477 

   478         return (minValue != null);

   479     }

   480 

   481     /**

   482      * Returns {@code true} if this {@code

   483      * OpenMBeanParameterInfoSupport} instance specifies a non-null

   484      * maximal value for the described parameter, {@code false}

   485      * otherwise.

   486      */

   487     public boolean hasMaxValue() {

   488 

   489         return (maxValue != null);

   490     }

   491 

   492 

   493     /**

   494      * Tests whether {@code obj} is a valid value for the parameter

   495      * described by this {@code OpenMBeanParameterInfo} instance.

   496      *

   497      * @param obj the object to be tested.

   498      *

   499      * @return {@code true} if {@code obj} is a valid value

   500      * for the parameter described by this

   501      * {@code OpenMBeanParameterInfo} instance,

   502      * {@code false} otherwise.

   503      */

   504     public boolean isValue(Object obj) {

   505         return OpenMBeanAttributeInfoSupport.isValue(this, obj);

   506         // compiler bug? should be able to omit class name here

   507         // also below in toString and hashCode

   508     }

   509 

   510 

   511     /* ***  Commodity methods from java.lang.Object  *** */

   512 

   513 

   514     /**

   515      * <p>Compares the specified {@code obj} parameter with this {@code

   516      * OpenMBeanParameterInfoSupport} instance for equality.</p>

   517      *

   518      * <p>Returns {@code true} if and only if all of the following

   519      * statements are true:

   520      *

   521      * <ul>

   522      * <li>{@code obj} is non null,</li>

   523      * <li>{@code obj} also implements the {@code OpenMBeanParameterInfo}

   524      * interface,</li>

   525      * <li>their names are equal</li>

   526      * <li>their open types are equal</li>

   527      * <li>their default, min, max and legal values are equal.</li>

   528      * </ul>

   529      * This ensures that this {@code equals} method works properly for

   530      * {@code obj} parameters which are different implementations of

   531      * the {@code OpenMBeanParameterInfo} interface.

   532      *

   533      * <p>If {@code obj} also implements {@link DescriptorRead}, then its

   534      * {@link DescriptorRead#getDescriptor() getDescriptor()} method must

   535      * also return the same value as for this object.</p>

   536      *

   537      * @param obj the object to be compared for equality with this

   538      * {@code OpenMBeanParameterInfoSupport} instance.

   539      *

   540      * @return {@code true} if the specified object is equal to this

   541      * {@code OpenMBeanParameterInfoSupport} instance.

   542      */

   543     public boolean equals(Object obj) {

   544         if (!(obj instanceof OpenMBeanParameterInfo))

   545             return false;

   546 

   547         OpenMBeanParameterInfo other = (OpenMBeanParameterInfo) obj;

   548 

   549         return equal(this, other);

   550     }

   551 

   552     /**

   553      * <p>Returns the hash code value for this {@code

   554      * OpenMBeanParameterInfoSupport} instance.</p>

   555      *

   556      * <p>The hash code of an {@code OpenMBeanParameterInfoSupport}

   557      * instance is the sum of the hash codes of all elements of

   558      * information used in {@code equals} comparisons (ie: its name,

   559      * its <i>open type</i>, its default, min, max and legal

   560      * values, and its Descriptor).

   561      *

   562      * <p>This ensures that {@code t1.equals(t2)} implies that {@code

   563      * t1.hashCode()==t2.hashCode()} for any two {@code

   564      * OpenMBeanParameterInfoSupport} instances {@code t1} and {@code

   565      * t2}, as required by the general contract of the method {@link

   566      * Object#hashCode() Object.hashCode()}.

   567      *

   568      * <p>However, note that another instance of a class implementing

   569      * the {@code OpenMBeanParameterInfo} interface may be equal to

   570      * this {@code OpenMBeanParameterInfoSupport} instance as defined

   571      * by {@link #equals(java.lang.Object)}, but may have a different

   572      * hash code if it is calculated differently.

   573      *

   574      * <p>As {@code OpenMBeanParameterInfoSupport} instances are

   575      * immutable, the hash code for this instance is calculated once,

   576      * on the first call to {@code hashCode}, and then the same value

   577      * is returned for subsequent calls.

   578      *

   579      * @return the hash code value for this {@code

   580      * OpenMBeanParameterInfoSupport} instance

   581      */

   582     public int hashCode() {

   583 

   584         // Calculate the hash code value if it has not yet been done

   585         // (ie 1st call to hashCode())

   586         //

   587         if (myHashCode == null)

   588             myHashCode = OpenMBeanAttributeInfoSupport.hashCode(this);

   589 

   590         // return always the same hash code for this instance (immutable)

   591         //

   592         return myHashCode.intValue();

   593     }

   594 

   595     /**

   596      * Returns a string representation of this

   597      * {@code OpenMBeanParameterInfoSupport} instance.

   598      * <p>

   599      * The string representation consists of the name of this class (i.e.

   600      * {@code javax.management.openmbean.OpenMBeanParameterInfoSupport}),

   601      * the string representation of the name and open type of the described

   602      * parameter, the string representation of its default, min, max and legal

   603      * values and the string representation of its descriptor.

   604      * <p>

   605      * As {@code OpenMBeanParameterInfoSupport} instances are immutable,

   606      * the string representation for this instance is calculated once,

   607      * on the first call to {@code toString}, and then the same value

   608      * is returned for subsequent calls.

   609      *

   610      * @return a string representation of this

   611      * {@code OpenMBeanParameterInfoSupport} instance.

   612      */

   613     public String toString() {

   614 

   615         // Calculate the string value if it has not yet been done (ie

   616         // 1st call to toString())

   617         //

   618         if (myToString == null)

   619             myToString = OpenMBeanAttributeInfoSupport.toString(this);

   620 

   621         // return always the same string representation for this

   622         // instance (immutable)

   623         //

   624         return myToString;

   625     }

   626 

   627 }