    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.lang3.builder;
    019
    020import java.lang.reflect.AccessibleObject;
    021import java.lang.reflect.Field;
    022import java.lang.reflect.Modifier;
    023import java.util.Arrays;
    024import java.util.Collection;
    025import java.util.Comparator;
    026import java.util.Objects;
    027
    028import org.apache.commons.lang3.ArraySorter;
    029import org.apache.commons.lang3.ArrayUtils;
    030import org.apache.commons.lang3.ClassUtils;
    031import org.apache.commons.lang3.stream.Streams;
    032
    033/**
    034 * Assists in implementing {@link Object#toString()} methods using reflection.
    035 *
    036 * <p>
    037 * This class uses reflection to determine the fields to append. Because these fields are usually private, the class
    038 * uses {@link java.lang.reflect.AccessibleObject#setAccessible(java.lang.reflect.AccessibleObject[], boolean)} to
    039 * change the visibility of the fields. This will fail under a security manager, unless the appropriate permissions are
    040 * set up correctly.
    041 * </p>
    042 * <p>
    043 * Using reflection to access (private) fields circumvents any synchronization protection guarding access to these
    044 * fields. If a toString method cannot safely read a field, you should exclude it from the toString method, or use
    045 * synchronization consistent with the class' lock management around the invocation of the method. Take special care to
    046 * exclude non-thread-safe collection classes, because these classes may throw ConcurrentModificationException if
    047 * modified while the toString method is executing.
    048 * </p>
    049 * <p>
    050 * A typical invocation for this method would look like:
    051 * </p>
    052 * <pre>
    053 * public String toString() {
    054 *     return ReflectionToStringBuilder.toString(this);
    055 * }
    056 * </pre>
    057 * <p>
    058 * You can also use the builder to debug 3rd party objects:
    059 * </p>
    060 * <pre>
    061 * System.out.println(&quot;An object: &quot; + ReflectionToStringBuilder.toString(anObject));
    062 * </pre>
    063 * <p>
    064 * A subclass can control field output by overriding the methods:
    065 * </p>
    066 * <ul>
    067 * <li>{@link #accept(java.lang.reflect.Field)}</li>
    068 * <li>{@link #getValue(java.lang.reflect.Field)}</li>
    069 * </ul>
    070 * <p>
    071 * For example, this method does <i>not</i> include the {@code password} field in the returned {@link String}:
    072 * </p>
    073 * <pre>
    074 * public String toString() {
    075 *     return (new ReflectionToStringBuilder(this) {
    076 *         protected boolean accept(Field f) {
    077 *             return super.accept(f) &amp;&amp; !f.getName().equals(&quot;password&quot;);
    078 *         }
    079 *     }).toString();
    080 * }
    081 * </pre>
    082 * <p>
    083 * Alternatively the {@link ToStringExclude} annotation can be used to exclude fields from being incorporated in the
    084 * result.
    085 * </p>
    086 * <p>
    087 * It is also possible to use the {@link ToStringSummary} annotation to output the summary information instead of the
    088 * detailed information of a field.
    089 * </p>
    090 * <p>
    091 * The exact format of the {@code toString} is determined by the {@link ToStringStyle} passed into the constructor.
    092 * </p>
    093 *
    094 * <p>
    095 * <b>Note:</b> the default {@link ToStringStyle} will only do a "shallow" formatting, i.e. composed objects are not
    096 * further traversed. To get "deep" formatting, use an instance of {@link RecursiveToStringStyle}.
    097 * </p>
    098 *
    099 * @since 2.0
    100 */
    101public class ReflectionToStringBuilder extends ToStringBuilder {
    102
    103    /**
    104     * Converts the given Collection into an array of Strings. The returned array does not contain {@code null}
    105     * entries. Note that {@link Arrays#sort(Object[])} will throw an {@link NullPointerException} if an array element
    106     * is {@code null}.
    107     *
    108     * @param collection
    109     *            The collection to convert
    110     * @return A new array of Strings.
    111     */
    112    static String[] toNoNullStringArray(final Collection<String> collection) {
    113        if (collection == null) {
    114            return ArrayUtils.EMPTY_STRING_ARRAY;
    115        }
    116        return toNoNullStringArray(collection.toArray());
    117    }
    118
    119    /**
    120     * Returns a new array of Strings without null elements. Internal method used to normalize exclude lists
    121     * (arrays and collections). Note that {@link Arrays#sort(Object[])} will throw an {@link NullPointerException}
    122     * if an array element is {@code null}.
    123     *
    124     * @param array
    125     *            The array to check
    126     * @return The given array or a new array without null.
    127     */
    128    static String[] toNoNullStringArray(final Object[] array) {
    129        return Streams.nonNull(array).map(Objects::toString).toArray(String[]::new);
    130    }
    131
    132    /**
    133     * Builds a {@code toString} value using the default {@link ToStringStyle} through reflection.
    134     *
    135     * <p>
    136     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    137     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    138     * also not as efficient as testing explicitly.
    139     * </p>
    140     *
    141     * <p>
    142     * Transient members will be not be included, as they are likely derived. Static fields will not be included.
    143     * Superclass fields will be appended.
    144     * </p>
    145     *
    146     * @param object
    147     *            the Object to be output
    148     * @return the String result
    149     * @throws IllegalArgumentException
    150     *             if the Object is {@code null}
    151     *
    152     * @see ToStringExclude
    153     * @see ToStringSummary
    154     */
    155    public static String toString(final Object object) {
    156        return toString(object, null, false, false, null);
    157    }
    158
    159    /**
    160     * Builds a {@code toString} value through reflection.
    161     *
    162     * <p>
    163     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    164     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    165     * also not as efficient as testing explicitly.
    166     * </p>
    167     *
    168     * <p>
    169     * Transient members will be not be included, as they are likely derived. Static fields will not be included.
    170     * Superclass fields will be appended.
    171     * </p>
    172     *
    173     * <p>
    174     * If the style is {@code null}, the default {@link ToStringStyle} is used.
    175     * </p>
    176     *
    177     * @param object
    178     *            the Object to be output
    179     * @param style
    180     *            the style of the {@code toString} to create, may be {@code null}
    181     * @return the String result
    182     * @throws IllegalArgumentException
    183     *             if the Object or {@link ToStringStyle} is {@code null}
    184     *
    185     * @see ToStringExclude
    186     * @see ToStringSummary
    187     */
    188    public static String toString(final Object object, final ToStringStyle style) {
    189        return toString(object, style, false, false, null);
    190    }
    191
    192    /**
    193     * Builds a {@code toString} value through reflection.
    194     *
    195     * <p>
    196     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    197     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    198     * also not as efficient as testing explicitly.
    199     * </p>
    200     *
    201     * <p>
    202     * If the {@code outputTransients} is {@code true}, transient members will be output, otherwise they
    203     * are ignored, as they are likely derived fields, and not part of the value of the Object.
    204     * </p>
    205     *
    206     * <p>
    207     * Static fields will not be included. Superclass fields will be appended.
    208     * </p>
    209     *
    210     * <p>
    211     * If the style is {@code null}, the default {@link ToStringStyle} is used.
    212     * </p>
    213     *
    214     * @param object
    215     *            the Object to be output
    216     * @param style
    217     *            the style of the {@code toString} to create, may be {@code null}
    218     * @param outputTransients
    219     *            whether to include transient fields
    220     * @return the String result
    221     * @throws IllegalArgumentException
    222     *             if the Object is {@code null}
    223     *
    224     * @see ToStringExclude
    225     * @see ToStringSummary
    226     */
    227    public static String toString(final Object object, final ToStringStyle style, final boolean outputTransients) {
    228        return toString(object, style, outputTransients, false, null);
    229    }
    230
    231    /**
    232     * Builds a {@code toString} value through reflection.
    233     *
    234     * <p>
    235     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    236     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    237     * also not as efficient as testing explicitly.
    238     * </p>
    239     *
    240     * <p>
    241     * If the {@code outputTransients} is {@code true}, transient fields will be output, otherwise they
    242     * are ignored, as they are likely derived fields, and not part of the value of the Object.
    243     * </p>
    244     *
    245     * <p>
    246     * If the {@code outputStatics} is {@code true}, static fields will be output, otherwise they are
    247     * ignored.
    248     * </p>
    249     *
    250     * <p>
    251     * Static fields will not be included. Superclass fields will be appended.
    252     * </p>
    253     *
    254     * <p>
    255     * If the style is {@code null}, the default {@link ToStringStyle} is used.
    256     * </p>
    257     *
    258     * @param object
    259     *            the Object to be output
    260     * @param style
    261     *            the style of the {@code toString} to create, may be {@code null}
    262     * @param outputTransients
    263     *            whether to include transient fields
    264     * @param outputStatics
    265     *            whether to include static fields
    266     * @return the String result
    267     * @throws IllegalArgumentException
    268     *             if the Object is {@code null}
    269     *
    270     * @see ToStringExclude
    271     * @see ToStringSummary
    272     * @since 2.1
    273     */
    274    public static String toString(final Object object, final ToStringStyle style, final boolean outputTransients, final boolean outputStatics) {
    275        return toString(object, style, outputTransients, outputStatics, null);
    276    }
    277
    278    /**
    279     * Builds a {@code toString} value through reflection.
    280     *
    281     * <p>
    282     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    283     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    284     * also not as efficient as testing explicitly.
    285     * </p>
    286     *
    287     * <p>
    288     * If the {@code outputTransients} is {@code true}, transient fields will be output, otherwise they
    289     * are ignored, as they are likely derived fields, and not part of the value of the Object.
    290     * </p>
    291     *
    292     * <p>
    293     * If the {@code outputStatics} is {@code true}, static fields will be output, otherwise they are
    294     * ignored.
    295     * </p>
    296     *
    297     * <p>
    298     * Superclass fields will be appended up to and including the specified superclass. A null superclass is treated as
    299     * {@code java.lang.Object}.
    300     * </p>
    301     *
    302     * <p>
    303     * If the style is {@code null}, the default {@link ToStringStyle} is used.
    304     * </p>
    305     *
    306     * @param <T>
    307     *            the type of the object
    308     * @param object
    309     *            the Object to be output
    310     * @param style
    311     *            the style of the {@code toString} to create, may be {@code null}
    312     * @param outputTransients
    313     *            whether to include transient fields
    314     * @param outputStatics
    315     *            whether to include static fields
    316     * @param excludeNullValues
    317     *            whether to exclude fields whose values are null
    318     * @param reflectUpToClass
    319     *            the superclass to reflect up to (inclusive), may be {@code null}
    320     * @return the String result
    321     * @throws IllegalArgumentException
    322     *             if the Object is {@code null}
    323     *
    324     * @see ToStringExclude
    325     * @see ToStringSummary
    326     * @since 3.6
    327     */
    328    public static <T> String toString(
    329            final T object, final ToStringStyle style, final boolean outputTransients,
    330            final boolean outputStatics, final boolean excludeNullValues, final Class<? super T> reflectUpToClass) {
    331        return new ReflectionToStringBuilder(object, style, null, reflectUpToClass, outputTransients, outputStatics, excludeNullValues)
    332                .toString();
    333    }
    334
    335    /**
    336     * Builds a {@code toString} value through reflection.
    337     *
    338     * <p>
    339     * It uses {@code AccessibleObject.setAccessible} to gain access to private fields. This means that it will
    340     * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
    341     * also not as efficient as testing explicitly.
    342     * </p>
    343     *
    344     * <p>
    345     * If the {@code outputTransients} is {@code true}, transient fields will be output, otherwise they
    346     * are ignored, as they are likely derived fields, and not part of the value of the Object.
    347     * </p>
    348     *
    349     * <p>
    350     * If the {@code outputStatics} is {@code true}, static fields will be output, otherwise they are
    351     * ignored.
    352     * </p>
    353     *
    354     * <p>
    355     * Superclass fields will be appended up to and including the specified superclass. A null superclass is treated as
    356     * {@code java.lang.Object}.
    357     * </p>
    358     *
    359     * <p>
    360     * If the style is {@code null}, the default {@link ToStringStyle} is used.
    361     * </p>
    362     *
    363     * @param <T>
    364     *            the type of the object
    365     * @param object
    366     *            the Object to be output
    367     * @param style
    368     *            the style of the {@code toString} to create, may be {@code null}
    369     * @param outputTransients
    370     *            whether to include transient fields
    371     * @param outputStatics
    372     *            whether to include static fields
    373     * @param reflectUpToClass
    374     *            the superclass to reflect up to (inclusive), may be {@code null}
    375     * @return the String result
    376     * @throws IllegalArgumentException
    377     *             if the Object is {@code null}
    378     *
    379     * @see ToStringExclude
    380     * @see ToStringSummary
    381     * @since 2.1
    382     */
    383    public static <T> String toString(
    384            final T object, final ToStringStyle style, final boolean outputTransients,
    385            final boolean outputStatics, final Class<? super T> reflectUpToClass) {
    386        return new ReflectionToStringBuilder(object, style, null, reflectUpToClass, outputTransients, outputStatics)
    387                .toString();
    388    }
    389
    390    /**
    391     * Builds a String for a toString method excluding the given field names.
    392     *
    393     * @param object
    394     *            The object to "toString".
    395     * @param excludeFieldNames
    396     *            The field names to exclude. Null excludes nothing.
    397     * @return The toString value.
    398     */
    399    public static String toStringExclude(final Object object, final Collection<String> excludeFieldNames) {
    400        return toStringExclude(object, toNoNullStringArray(excludeFieldNames));
    401    }
    402
    403    /**
    404     * Builds a String for a toString method excluding the given field names.
    405     *
    406     * @param object
    407     *            The object to "toString".
    408     * @param excludeFieldNames
    409     *            The field names to exclude
    410     * @return The toString value.
    411     */
    412    public static String toStringExclude(final Object object, final String... excludeFieldNames) {
    413        return new ReflectionToStringBuilder(object).setExcludeFieldNames(excludeFieldNames).toString();
    414    }
    415
    416
    417    /**
    418     * Builds a String for a toString method including the given field names.
    419     *
    420     * @param object
    421     *            The object to "toString".
    422     * @param includeFieldNames
    423     *            {@code null} or empty means all fields are included. All fields are included by default. This method will override the default behavior.
    424     * @return The toString value.
    425     * @since 3.13.0
    426     */
    427    public static String toStringInclude(final Object object, final Collection<String> includeFieldNames) {
    428        return toStringInclude(object, toNoNullStringArray(includeFieldNames));
    429    }
    430
    431    /**
    432     * Builds a String for a toString method including the given field names.
    433     *
    434     * @param object
    435     *            The object to "toString".
    436     * @param includeFieldNames
    437     *            The field names to include. {@code null} or empty means all fields are included. All fields are included by default. This method will override the default
    438     *             behavior.
    439     * @return The toString value.
    440     * @since 3.13.0
    441     */
    442    public static String toStringInclude(final Object object, final String... includeFieldNames) {
    443        return new ReflectionToStringBuilder(object).setIncludeFieldNames(includeFieldNames).toString();
    444    }
    445
    446    /**
    447     * Whether or not to append static fields.
    448     */
    449    private boolean appendStatics;
    450
    451    /**
    452     * Whether or not to append transient fields.
    453     */
    454    private boolean appendTransients;
    455
    456    /**
    457     * Whether or not to append fields that are null.
    458     */
    459    private boolean excludeNullValues;
    460
    461    /**
    462     * Which field names to exclude from output. Intended for fields like {@code "password"}.
    463     *
    464     * @since 3.0 this is protected instead of private
    465     */
    466    protected String[] excludeFieldNames;
    467
    468    /**
    469     * Field names that will be included in the output. All fields are included by default.
    470     *
    471     * @since 3.13.0
    472     */
    473    protected String[] includeFieldNames;
    474
    475    /**
    476     * The last super class to stop appending fields for.
    477     */
    478    private Class<?> upToClass;
    479
    480    /**
    481     * Constructs a new instance.
    482     *
    483     * <p>
    484     * This constructor outputs using the default style set with {@code setDefaultStyle}.
    485     * </p>
    486     *
    487     * @param object
    488     *            the Object to build a {@code toString} for, must not be {@code null}
    489     */
    490    public ReflectionToStringBuilder(final Object object) {
    491        super(object);
    492    }
    493
    494    /**
    495     * Constructs a new instance.
    496     *
    497     * <p>
    498     * If the style is {@code null}, the default style is used.
    499     * </p>
    500     *
    501     * @param object
    502     *            the Object to build a {@code toString} for, must not be {@code null}
    503     * @param style
    504     *            the style of the {@code toString} to create, may be {@code null}
    505     */
    506    public ReflectionToStringBuilder(final Object object, final ToStringStyle style) {
    507        super(object, style);
    508    }
    509
    510    /**
    511     * Constructs a new instance.
    512     *
    513     * <p>
    514     * If the style is {@code null}, the default style is used.
    515     * </p>
    516     *
    517     * <p>
    518     * If the buffer is {@code null}, a new one is created.
    519     * </p>
    520     *
    521     * @param object
    522     *            the Object to build a {@code toString} for
    523     * @param style
    524     *            the style of the {@code toString} to create, may be {@code null}
    525     * @param buffer
    526     *            the {@link StringBuffer} to populate, may be {@code null}
    527     */
    528    public ReflectionToStringBuilder(final Object object, final ToStringStyle style, final StringBuffer buffer) {
    529        super(object, style, buffer);
    530    }
    531
    532    /**
    533     * Constructs a new instance.
    534     *
    535     * @param <T>
    536     *            the type of the object
    537     * @param object
    538     *            the Object to build a {@code toString} for
    539     * @param style
    540     *            the style of the {@code toString} to create, may be {@code null}
    541     * @param buffer
    542     *            the {@link StringBuffer} to populate, may be {@code null}
    543     * @param reflectUpToClass
    544     *            the superclass to reflect up to (inclusive), may be {@code null}
    545     * @param outputTransients
    546     *            whether to include transient fields
    547     * @param outputStatics
    548     *            whether to include static fields
    549     * @since 2.1
    550     */
    551    public <T> ReflectionToStringBuilder(
    552            final T object, final ToStringStyle style, final StringBuffer buffer,
    553            final Class<? super T> reflectUpToClass, final boolean outputTransients, final boolean outputStatics) {
    554        super(object, style, buffer);
    555        this.setUpToClass(reflectUpToClass);
    556        this.setAppendTransients(outputTransients);
    557        this.setAppendStatics(outputStatics);
    558    }
    559
    560    /**
    561     * Constructs a new instance.
    562     *
    563     * @param <T>
    564     *            the type of the object
    565     * @param object
    566     *            the Object to build a {@code toString} for
    567     * @param style
    568     *            the style of the {@code toString} to create, may be {@code null}
    569     * @param buffer
    570     *            the {@link StringBuffer} to populate, may be {@code null}
    571     * @param reflectUpToClass
    572     *            the superclass to reflect up to (inclusive), may be {@code null}
    573     * @param outputTransients
    574     *            whether to include transient fields
    575     * @param outputStatics
    576     *            whether to include static fields
    577     * @param excludeNullValues
    578     *            whether to exclude fields who value is null
    579     * @since 3.6
    580     */
    581    public <T> ReflectionToStringBuilder(
    582            final T object, final ToStringStyle style, final StringBuffer buffer,
    583            final Class<? super T> reflectUpToClass, final boolean outputTransients, final boolean outputStatics,
    584            final boolean excludeNullValues) {
    585        super(object, style, buffer);
    586        this.setUpToClass(reflectUpToClass);
    587        this.setAppendTransients(outputTransients);
    588        this.setAppendStatics(outputStatics);
    589        this.setExcludeNullValues(excludeNullValues);
    590    }
    591
    592    /**
    593     * Returns whether or not to append the given {@link Field}.
    594     * <ul>
    595     * <li>Transient fields are appended only if {@link #isAppendTransients()} returns {@code true}.
    596     * <li>Static fields are appended only if {@link #isAppendStatics()} returns {@code true}.
    597     * <li>Inner class fields are not appended.</li>
    598     * </ul>
    599     *
    600     * @param field
    601     *            The Field to test.
    602     * @return Whether or not to append the given {@link Field}.
    603     */
    604    protected boolean accept(final Field field) {
    605        if (field.getName().indexOf(ClassUtils.INNER_CLASS_SEPARATOR_CHAR) != -1) {
    606            // Reject field from inner class.
    607            return false;
    608        }
    609        if (Modifier.isTransient(field.getModifiers()) && !this.isAppendTransients()) {
    610            // Reject transient fields.
    611            return false;
    612        }
    613        if (Modifier.isStatic(field.getModifiers()) && !this.isAppendStatics()) {
    614            // Reject static fields.
    615            return false;
    616        }
    617
    618        if (this.excludeFieldNames != null
    619            && Arrays.binarySearch(this.excludeFieldNames, field.getName()) >= 0) {
    620            // Reject fields from the getExcludeFieldNames list.
    621            return false;
    622        }
    623
    624        if (ArrayUtils.isNotEmpty(includeFieldNames)) {
    625            // Accept fields from the getIncludeFieldNames list. {@code null} or empty means all fields are included. All fields are included by default.
    626            return Arrays.binarySearch(this.includeFieldNames, field.getName()) >= 0;
    627        }
    628
    629        return !field.isAnnotationPresent(ToStringExclude.class);
    630    }
    631
    632    /**
    633     * Appends the fields and values defined by the given object of the given Class.
    634     *
    635     * <p>
    636     * If a cycle is detected as an object is &quot;toString()'ed&quot;, such an object is rendered as if
    637     * {@code Object.toString()} had been called and not implemented by the object.
    638     * </p>
    639     *
    640     * @param clazz
    641     *            The class of object parameter
    642     */
    643    protected void appendFieldsIn(final Class<?> clazz) {
    644        if (clazz.isArray()) {
    645            this.reflectionAppendArray(this.getObject());
    646            return;
    647        }
    648        // The elements in the returned array are not sorted and are not in any particular order.
    649        final Field[] fields = ArraySorter.sort(clazz.getDeclaredFields(), Comparator.comparing(Field::getName));
    650        AccessibleObject.setAccessible(fields, true);
    651        for (final Field field : fields) {
    652            final String fieldName = field.getName();
    653            if (this.accept(field)) {
    654                try {
    655                    // Warning: Field.get(Object) creates wrappers objects
    656                    // for primitive types.
    657                    final Object fieldValue = this.getValue(field);
    658                    if (!excludeNullValues || fieldValue != null) {
    659                        this.append(fieldName, fieldValue, !field.isAnnotationPresent(ToStringSummary.class));
    660                    }
    661                } catch (final IllegalAccessException e) {
    662                    // this can't happen. Would get a Security exception instead throw a runtime exception in case the
    663                    // impossible happens.
    664                    throw new IllegalStateException(e);
    665                }
    666            }
    667        }
    668    }
    669
    670    /**
    671     * Gets the excludeFieldNames.
    672     *
    673     * @return the excludeFieldNames.
    674     */
    675    public String[] getExcludeFieldNames() {
    676        return this.excludeFieldNames.clone();
    677    }
    678
    679    /**
    680     * Gets the includeFieldNames
    681     *
    682     * @return the includeFieldNames.
    683     * @since 3.13.0
    684     */
    685    public String[] getIncludeFieldNames() {
    686        return this.includeFieldNames.clone();
    687    }
    688
    689    /**
    690     * Gets the last super class to stop appending fields for.
    691     *
    692     * @return The last super class to stop appending fields for.
    693     */
    694    public Class<?> getUpToClass() {
    695        return this.upToClass;
    696    }
    697
    698    /**
    699     * Calls {@code java.lang.reflect.Field.get(Object)}.
    700     *
    701     * @param field
    702     *            The Field to query.
    703     * @return The Object from the given Field.
    704     *
    705     * @throws IllegalArgumentException
    706     *             see {@link java.lang.reflect.Field#get(Object)}
    707     * @throws IllegalAccessException
    708     *             see {@link java.lang.reflect.Field#get(Object)}
    709     *
    710     * @see java.lang.reflect.Field#get(Object)
    711     */
    712    protected Object getValue(final Field field) throws IllegalAccessException {
    713        return field.get(this.getObject());
    714    }
    715
    716    /**
    717     * Gets whether or not to append static fields.
    718     *
    719     * @return Whether or not to append static fields.
    720     * @since 2.1
    721     */
    722    public boolean isAppendStatics() {
    723        return this.appendStatics;
    724    }
    725
    726    /**
    727     * Gets whether or not to append transient fields.
    728     *
    729     * @return Whether or not to append transient fields.
    730     */
    731    public boolean isAppendTransients() {
    732        return this.appendTransients;
    733    }
    734
    735    /**
    736     * Gets whether or not to append fields whose values are null.
    737     *
    738     * @return Whether or not to append fields whose values are null.
    739     * @since 3.6
    740     */
    741    public boolean isExcludeNullValues() {
    742        return this.excludeNullValues;
    743    }
    744
    745    /**
    746     * Appends to the {@code toString} an {@link Object} array.
    747     *
    748     * @param array
    749     *            the array to add to the {@code toString}
    750     * @return this
    751     */
    752    public ReflectionToStringBuilder reflectionAppendArray(final Object array) {
    753        this.getStyle().reflectionAppendArrayDetail(this.getStringBuffer(), null, array);
    754        return this;
    755    }
    756
    757    /**
    758     * Sets whether or not to append static fields.
    759     *
    760     * @param appendStatics
    761     *            Whether or not to append static fields.
    762     * @since 2.1
    763     */
    764    public void setAppendStatics(final boolean appendStatics) {
    765        this.appendStatics = appendStatics;
    766    }
    767
    768    /**
    769     * Sets whether or not to append transient fields.
    770     *
    771     * @param appendTransients
    772     *            Whether or not to append transient fields.
    773     */
    774    public void setAppendTransients(final boolean appendTransients) {
    775        this.appendTransients = appendTransients;
    776    }
    777
    778    /**
    779     * Sets the field names to exclude.
    780     *
    781     * @param excludeFieldNamesParam
    782     *            The excludeFieldNames to excluding from toString or {@code null}.
    783     * @return {@code this}
    784     */
    785    public ReflectionToStringBuilder setExcludeFieldNames(final String... excludeFieldNamesParam) {
    786        if (excludeFieldNamesParam == null) {
    787            this.excludeFieldNames = null;
    788        } else {
    789            // clone and remove nulls
    790            this.excludeFieldNames = ArraySorter.sort(toNoNullStringArray(excludeFieldNamesParam));
    791        }
    792        return this;
    793    }
    794
    795    /**
    796     * Sets whether or not to append fields whose values are null.
    797     *
    798     * @param excludeNullValues
    799     *            Whether or not to append fields whose values are null.
    800     * @since 3.6
    801     */
    802    public void setExcludeNullValues(final boolean excludeNullValues) {
    803        this.excludeNullValues = excludeNullValues;
    804    }
    805
    806    /**
    807     * Sets the field names to include. {@code null} or empty means all fields are included. All fields are included by default. This method will override the default behavior.
    808     *
    809     * @param includeFieldNamesParam
    810     *            The includeFieldNames that must be on toString or {@code null}.
    811     * @return {@code this}
    812     * @since 3.13.0
    813     */
    814    public ReflectionToStringBuilder setIncludeFieldNames(final String... includeFieldNamesParam) {
    815        if (includeFieldNamesParam == null) {
    816            this.includeFieldNames = null;
    817        } else {
    818            // clone and remove nulls
    819            this.includeFieldNames = ArraySorter.sort(toNoNullStringArray(includeFieldNamesParam));
    820        }
    821        return this;
    822    }
    823
    824    /**
    825     * Sets the last super class to stop appending fields for.
    826     *
    827     * @param clazz
    828     *            The last super class to stop appending fields for.
    829     */
    830    public void setUpToClass(final Class<?> clazz) {
    831        if (clazz != null) {
    832            final Object object = getObject();
    833            if (object != null && !clazz.isInstance(object)) {
    834                throw new IllegalArgumentException("Specified class is not a superclass of the object");
    835            }
    836        }
    837        this.upToClass = clazz;
    838    }
    839
    840    /**
    841     * Gets the String built by this builder.
    842     *
    843     * @return the built string
    844     */
    845    @Override
    846    public String toString() {
    847        if (this.getObject() == null) {
    848            return this.getStyle().getNullText();
    849        }
    850
    851        validate();
    852
    853        Class<?> clazz = this.getObject().getClass();
    854        this.appendFieldsIn(clazz);
    855        while (clazz.getSuperclass() != null && clazz != this.getUpToClass()) {
    856            clazz = clazz.getSuperclass();
    857            this.appendFieldsIn(clazz);
    858        }
    859        return super.toString();
    860    }
    861
    862    /**
    863     * Validates that include and exclude names do not intersect.
    864     */
    865    private void validate() {
    866        if (ArrayUtils.containsAny(this.excludeFieldNames, (Object[]) this.includeFieldNames)) {
    867            ToStringStyle.unregister(this.getObject());
    868            throw new IllegalStateException("includeFieldNames and excludeFieldNames must not intersect");
    869        }
    870    }
    871
    872}