Package org.apache.commons.lang3.builder

Class ReflectionDiffBuilder<T>

  • Type Parameters:
    T - type of the left and right object to diff.
    All Implemented Interfaces:
    Builder<DiffResult<T>>
    public class ReflectionDiffBuilder<T>
extends java.lang.Object
implements Builder<DiffResult<T>>

    Assists in implementing Diffable.diff(Object) methods.

    All non-static, non-transient fields (including inherited fields) of the objects to diff are discovered using reflection and compared for differences.

    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 ReflectionDiffBuilder(this, obj, ToStringStyle.SHORT_PREFIX_STYLE)
       .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).

    Since:
    3.6
    See Also:
    Diffable, Diff, DiffResult, ToStringStyle

    • Constructor Summary

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

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      DiffResult<T> build()
      Returns a reference to the object being constructed or result being calculated by the builder.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • ReflectionDiffBuilder

        public ReflectionDiffBuilder​(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.

        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.IllegalArgumentException - if lhs or rhs is null

    • Method Detail

      • build

        public DiffResult<T> build()
        Description copied from interface: Builder
        Returns a reference to the object being constructed or result being calculated by the builder.
        Specified by:
        build in interface Builder<T>
        Returns:
        the object constructed or result calculated by the builder.