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Statistical sampling library for use in virtdata libraries, based on apache commons math 4

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang3.builder;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.Validate;

/**
 * 

* Assists in implementing {@link Diffable#diff(Object)} methods. *

* *

* To use this class, write code as follows: *

* *
 * public class Person implements Diffable<Person> {
 *   String name;
 *   int age;
 *   boolean smoker;
 *
 *   ...
 *
 *   public DiffResult diff(Person obj) {
 *     // No need for null check, as NullPointerException correct if obj is null
 *     return new DiffBuilder(this, obj, ToStringStyle.SHORT_PREFIX_STYLE)
 *       .append("name", this.name, obj.name)
 *       .append("age", this.age, obj.age)
 *       .append("smoker", this.smoker, obj.smoker)
 *       .build();
 *   }
 * }
 * 
* *

* The {@code ToStringStyle} passed to the constructor is embedded in the * returned {@code DiffResult} and influences the style of the * {@code DiffResult.toString()} method. This style choice can be overridden by * calling {@link DiffResult#toString(ToStringStyle)}. *

* * @since 3.3 * @see Diffable * @see Diff * @see DiffResult * @see ToStringStyle */ public class DiffBuilder implements Builder { private final List> diffs; private final boolean objectsTriviallyEqual; private final Object left; private final Object right; private final ToStringStyle style; /** *

* Constructs a builder for the specified objects with the specified style. *

* *

* If {@code lhs == rhs} or {@code lhs.equals(rhs)} then the builder will * not evaluate any calls to {@code append(...)} and will return an empty * {@link DiffResult} when {@link #build()} is executed. *

* * @param lhs * {@code this} object * @param rhs * the object to diff against * @param style * the style will use when outputting the objects, {@code null} * uses the default * @param testTriviallyEqual * If true, this will test if lhs and rhs are the same or equal. * All of the append(fieldName, lhs, rhs) methods will abort * without creating a field {@link Diff} if the trivially equal * test is enabled and returns true. The result of this test * is never changed throughout the life of this {@link DiffBuilder}. * @throws IllegalArgumentException * if {@code lhs} or {@code rhs} is {@code null} * @since 3.4 */ public DiffBuilder(final Object lhs, final Object rhs, final ToStringStyle style, final boolean testTriviallyEqual) { Validate.isTrue(lhs != null, "lhs cannot be null"); Validate.isTrue(rhs != null, "rhs cannot be null"); this.diffs = new ArrayList<>(); this.left = lhs; this.right = rhs; this.style = style; // Don't compare any fields if objects equal this.objectsTriviallyEqual = testTriviallyEqual && (lhs == rhs || lhs.equals(rhs)); } /** *

* Constructs a builder for the specified objects with the specified style. *

* *

* If {@code lhs == rhs} or {@code lhs.equals(rhs)} then the builder will * not evaluate any calls to {@code append(...)} and will return an empty * {@link DiffResult} when {@link #build()} is executed. *

* *

* This delegates to {@link #DiffBuilder(Object, Object, ToStringStyle, boolean)} * with the testTriviallyEqual flag enabled. *

* * @param lhs * {@code this} object * @param rhs * the object to diff against * @param style * the style will use when outputting the objects, {@code null} * uses the default * @throws IllegalArgumentException * if {@code lhs} or {@code rhs} is {@code null} */ public DiffBuilder(final Object lhs, final Object rhs, final ToStringStyle style) { this(lhs, rhs, style, true); } /** *

* Test if two {@code boolean}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code boolean} * @param rhs * the right hand {@code boolean} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final boolean lhs, final boolean rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Boolean getLeft() { return Boolean.valueOf(lhs); } @Override public Boolean getRight() { return Boolean.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code boolean[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code boolean[]} * @param rhs * the right hand {@code boolean[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final boolean[] lhs, final boolean[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Boolean[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Boolean[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code byte}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code byte} * @param rhs * the right hand {@code byte} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final byte lhs, final byte rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Byte getLeft() { return Byte.valueOf(lhs); } @Override public Byte getRight() { return Byte.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code byte[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code byte[]} * @param rhs * the right hand {@code byte[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final byte[] lhs, final byte[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Byte[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Byte[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code char}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code char} * @param rhs * the right hand {@code char} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final char lhs, final char rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Character getLeft() { return Character.valueOf(lhs); } @Override public Character getRight() { return Character.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code char[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code char[]} * @param rhs * the right hand {@code char[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final char[] lhs, final char[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Character[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Character[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code double}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code double} * @param rhs * the right hand {@code double} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final double lhs, final double rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (Double.doubleToLongBits(lhs) != Double.doubleToLongBits(rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Double getLeft() { return Double.valueOf(lhs); } @Override public Double getRight() { return Double.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code double[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code double[]} * @param rhs * the right hand {@code double[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final double[] lhs, final double[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Double[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Double[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code float}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code float} * @param rhs * the right hand {@code float} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final float lhs, final float rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (Float.floatToIntBits(lhs) != Float.floatToIntBits(rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Float getLeft() { return Float.valueOf(lhs); } @Override public Float getRight() { return Float.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code float[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code float[]} * @param rhs * the right hand {@code float[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final float[] lhs, final float[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Float[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Float[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code int}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code int} * @param rhs * the right hand {@code int} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final int lhs, final int rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Integer getLeft() { return Integer.valueOf(lhs); } @Override public Integer getRight() { return Integer.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code int[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code int[]} * @param rhs * the right hand {@code int[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final int[] lhs, final int[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Integer[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Integer[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code long}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code long} * @param rhs * the right hand {@code long} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final long lhs, final long rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Long getLeft() { return Long.valueOf(lhs); } @Override public Long getRight() { return Long.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code long[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code long[]} * @param rhs * the right hand {@code long[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final long[] lhs, final long[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Long[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Long[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code short}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code short} * @param rhs * the right hand {@code short} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final short lhs, final short rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs != rhs) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Short getLeft() { return Short.valueOf(lhs); } @Override public Short getRight() { return Short.valueOf(rhs); } }); } return this; } /** *

* Test if two {@code short[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code short[]} * @param rhs * the right hand {@code short[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final short[] lhs, final short[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Short[] getLeft() { return ArrayUtils.toObject(lhs); } @Override public Short[] getRight() { return ArrayUtils.toObject(rhs); } }); } return this; } /** *

* Test if two {@code Objects}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code Object} * @param rhs * the right hand {@code Object} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final Object lhs, final Object rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (lhs == rhs) { return this; } Object objectToTest; if (lhs != null) { objectToTest = lhs; } else { // rhs cannot be null, as lhs != rhs objectToTest = rhs; } if (objectToTest.getClass().isArray()) { if (objectToTest instanceof boolean[]) { return append(fieldName, (boolean[]) lhs, (boolean[]) rhs); } if (objectToTest instanceof byte[]) { return append(fieldName, (byte[]) lhs, (byte[]) rhs); } if (objectToTest instanceof char[]) { return append(fieldName, (char[]) lhs, (char[]) rhs); } if (objectToTest instanceof double[]) { return append(fieldName, (double[]) lhs, (double[]) rhs); } if (objectToTest instanceof float[]) { return append(fieldName, (float[]) lhs, (float[]) rhs); } if (objectToTest instanceof int[]) { return append(fieldName, (int[]) lhs, (int[]) rhs); } if (objectToTest instanceof long[]) { return append(fieldName, (long[]) lhs, (long[]) rhs); } if (objectToTest instanceof short[]) { return append(fieldName, (short[]) lhs, (short[]) rhs); } return append(fieldName, (Object[]) lhs, (Object[]) rhs); } // Not array type if (lhs != null && lhs.equals(rhs)) { return this; } diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Object getLeft() { return lhs; } @Override public Object getRight() { return rhs; } }); return this; } /** *

* Test if two {@code Object[]}s are equal. *

* * @param fieldName * the field name * @param lhs * the left hand {@code Object[]} * @param rhs * the right hand {@code Object[]} * @return this * @throws IllegalArgumentException * if field name is {@code null} */ public DiffBuilder append(final String fieldName, final Object[] lhs, final Object[] rhs) { validateFieldNameNotNull(fieldName); if (objectsTriviallyEqual) { return this; } if (!Arrays.equals(lhs, rhs)) { diffs.add(new Diff(fieldName) { private static final long serialVersionUID = 1L; @Override public Object[] getLeft() { return lhs; } @Override public Object[] getRight() { return rhs; } }); } return this; } /** *

* Append diffs from another {@code DiffResult}. *

* *

* This method is useful if you want to compare properties which are * themselves Diffable and would like to know which specific part of * it is different. *

* *
     * public class Person implements Diffable<Person> {
     *   String name;
     *   Address address; // implements Diffable<Address>
     *
     *   ...
     *
     *   public DiffResult diff(Person obj) {
     *     return new DiffBuilder(this, obj, ToStringStyle.SHORT_PREFIX_STYLE)
     *       .append("name", this.name, obj.name)
     *       .append("address", this.address.diff(obj.address))
     *       .build();
     *   }
     * }
     * 
* * @param fieldName * the field name * @param diffResult * the {@code DiffResult} to append * @return this * @throws IllegalArgumentException * if field name is {@code null} * @since 3.5 */ public DiffBuilder append(final String fieldName, final DiffResult diffResult) { validateFieldNameNotNull(fieldName); Validate.isTrue(diffResult != null, "Diff result cannot be null"); if (objectsTriviallyEqual) { return this; } for (final Diff diff : diffResult.getDiffs()) { append(fieldName + "." + diff.getFieldName(), diff.getLeft(), diff.getRight()); } return this; } /** *

* Builds a {@link DiffResult} based on the differences appended to this * builder. *

* * @return a {@code DiffResult} containing the differences between the two * objects. */ @Override public DiffResult build() { return new DiffResult(left, right, diffs, style); } private void validateFieldNameNotNull(final String fieldName) { Validate.isTrue(fieldName != null, "Field name cannot be null"); } }