Package org.apache.commons.lang3.builder

Class DiffBuilder<T>

  • Type Parameters:
    T - type of the left and right object.
    All Implemented Interfaces:
    Builder<DiffResult<T>>
    public class DiffBuilder<T>
extends java.lang.Object
implements Builder<DiffResult<T>>
    Assists in implementing 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 ToStringStyle passed to the constructor is embedded in the returned DiffResult and influences the style of the DiffResult.toString() method. This style choice can be overridden by calling DiffResult.toString(ToStringStyle).

    See ReflectionDiffBuilder for a reflection based version of this class.

    Since:
    3.3
    See Also:
    Diffable, Diff, DiffResult, ToStringStyle, ReflectionDiffBuilder

    • Constructor Summary

      Constructors 
      Constructor Description
      DiffBuilder​(T lhs, T rhs, ToStringStyle style)
      Constructs a builder for the specified objects with the specified style.
      DiffBuilder​(T lhs, T rhs, ToStringStyle style, boolean testTriviallyEqual)
      Constructs a builder for the specified objects with the specified style.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      DiffBuilder<T> append​(java.lang.String fieldName, boolean[] lhs, boolean[] rhs)
      Test if two boolean[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, boolean lhs, boolean rhs)
      Test if two booleans are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, byte[] lhs, byte[] rhs)
      Test if two byte[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, byte lhs, byte rhs)
      Test if two bytes are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, char[] lhs, char[] rhs)
      Test if two char[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, char lhs, char rhs)
      Test if two chars are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, double[] lhs, double[] rhs)
      Test if two double[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, double lhs, double rhs)
      Test if two doubles are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, float[] lhs, float[] rhs)
      Test if two float[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, float lhs, float rhs)
      Test if two floats are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, int[] lhs, int[] rhs)
      Test if two int[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, int lhs, int rhs)
      Test if two ints are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, long[] lhs, long[] rhs)
      Test if two long[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, long lhs, long rhs)
      Test if two longs are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, short[] lhs, short[] rhs)
      Test if two short[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, short lhs, short rhs)
      Test if two shorts are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, java.lang.Object[] lhs, java.lang.Object[] rhs)
      Test if two Object[]s are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, java.lang.Object lhs, java.lang.Object rhs)
      Test if two Objectss are equal.
      DiffBuilder<T> append​(java.lang.String fieldName, DiffResult<T> diffResult)
      Append diffs from another DiffResult.
      DiffResult<T> build()
      Builds a DiffResult based on the differences appended to this builder.

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • DiffBuilder

        public DiffBuilder​(T lhs,
                   T rhs,
                   ToStringStyle style)
        Constructs a builder for the specified objects with the specified style.

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

        This delegates to DiffBuilder(Object, Object, ToStringStyle, boolean) with the testTriviallyEqual flag enabled.

        Parameters:
        lhs - this object
        rhs - the object to diff against
        style - the style will use when outputting the objects, null uses the default
        Throws:
        java.lang.NullPointerException - if lhs or rhs is null

      • DiffBuilder

        public DiffBuilder​(T lhs,
                   T rhs,
                   ToStringStyle style,
                   boolean testTriviallyEqual)
        Constructs a builder for the specified objects with the specified style.

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

        Parameters:
        lhs - this object
        rhs - the object to diff against
        style - the style will use when outputting the objects, null uses the default
        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 Diff if the trivially equal test is enabled and returns true. The result of this test is never changed throughout the life of this DiffBuilder.
        Throws:
        java.lang.NullPointerException - if lhs or rhs is null
        Since:
        3.4

    • Method Detail

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             boolean lhs,
                             boolean rhs)
        Test if two booleans are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand boolean
        rhs - the right-hand boolean
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             boolean[] lhs,
                             boolean[] rhs)
        Test if two boolean[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand boolean[]
        rhs - the right-hand boolean[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             byte lhs,
                             byte rhs)
        Test if two bytes are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand byte
        rhs - the right-hand byte
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             byte[] lhs,
                             byte[] rhs)
        Test if two byte[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand byte[]
        rhs - the right-hand byte[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             char lhs,
                             char rhs)
        Test if two chars are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand char
        rhs - the right-hand char
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             char[] lhs,
                             char[] rhs)
        Test if two char[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand char[]
        rhs - the right-hand char[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             DiffResult<T> diffResult)
        Append diffs from another 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();
   }
 }
        Parameters:
        fieldName - the field name
        diffResult - the DiffResult to append
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null or diffResult is null
        Since:
        3.5

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             double lhs,
                             double rhs)
        Test if two doubles are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand double
        rhs - the right-hand double
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             double[] lhs,
                             double[] rhs)
        Test if two double[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand double[]
        rhs - the right-hand double[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             float lhs,
                             float rhs)
        Test if two floats are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand float
        rhs - the right-hand float
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             float[] lhs,
                             float[] rhs)
        Test if two float[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand float[]
        rhs - the right-hand float[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             int lhs,
                             int rhs)
        Test if two ints are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand int
        rhs - the right-hand int
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             int[] lhs,
                             int[] rhs)
        Test if two int[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand int[]
        rhs - the right-hand int[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             long lhs,
                             long rhs)
        Test if two longs are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand long
        rhs - the right-hand long
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             long[] lhs,
                             long[] rhs)
        Test if two long[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand long[]
        rhs - the right-hand long[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             java.lang.Object lhs,
                             java.lang.Object rhs)
        Test if two Objectss are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand Object
        rhs - the right-hand Object
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             java.lang.Object[] lhs,
                             java.lang.Object[] rhs)
        Test if two Object[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand Object[]
        rhs - the right-hand Object[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             short lhs,
                             short rhs)
        Test if two shorts are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand short
        rhs - the right-hand short
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • append

        public DiffBuilder<T> append​(java.lang.String fieldName,
                             short[] lhs,
                             short[] rhs)
        Test if two short[]s are equal.
        Parameters:
        fieldName - the field name
        lhs - the left-hand short[]
        rhs - the right-hand short[]
        Returns:
        this
        Throws:
        java.lang.NullPointerException - if field name is null

      • build

        public DiffResult<T> build()
        Builds a DiffResult based on the differences appended to this builder.
        Specified by:
        build in interface Builder<T>
        Returns:
        a DiffResult containing the differences between the two objects.