EqualsBuilder (Javadocs: proscene)

java.lang.Object
- remixlab.util.EqualsBuilder

```
public class EqualsBuilder
extends Object
```
Assists in implementing Object.equals(Object) methods.

This class provides methods to build a good equals method for any class. It follows rules laid out in Effective Java , by Joshua Bloch. In particular the rule for comparing doubles, floats, and arrays can be tricky. Also, making sure that equals() and hashCode() are consistent can be difficult.

Two Objects that compare as equals must generate the same hash code, but two Objects with the same hash code do not have to be equal.

All relevant fields should be included in the calculation of equals. Derived fields may be ignored. In particular, any field used in generating a hash code must be used in the equals method, and vice versa.

Typical use for the code is as follows:
```
 public boolean equals(Object obj) {
   if (obj == null) {
     return false;
   }
   if (obj == this) {
     return true;
   }
   if (obj.getClass() != getClass()) {
     return false;
   }
   MyClass rhs = (MyClass) obj;
   return new EqualsBuilder().appendSuper(super.equals(obj)).append(field1, rhs.field1).append(field2, rhs.field2)
       .append(field3, rhs.field3).isEquals();
 }
 
```
Alternatively, there is a method that uses reflection to determine the fields to test. Because these fields are usually private, the method, reflectionEquals, uses AccessibleObject.setAccessible to change the visibility of the fields. This will fail under a security manager, unless the appropriate permissions are set up correctly. It is also slower than testing explicitly.

A typical invocation for this method would look like:
```
 public boolean equals(Object obj) {
   return EqualsBuilder.reflectionEquals(this, obj);
 }
 
```
Since:

1.0

Author:

Apache Software Foundation, Steve Downey, Gary Gregory, Pete Gieser, Arun Mammen Thomas, Oliver Sauder, Daniel Bell

Constructor Summary

Constructors
Constructor and Description

EqualsBuilder()
Constructor for EqualsBuilder.

Constructors
Constructor and Description
`EqualsBuilder()` Constructor for EqualsBuilder.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`EqualsBuilder`	`append(boolean[] lhs, boolean[] rhs)` Deep comparison of array of `boolean`.
`EqualsBuilder`	`append(boolean lhs, boolean rhs)` Test if two `booleans`s are equal.
`EqualsBuilder`	`append(byte[] lhs, byte[] rhs)` Deep comparison of array of `byte`.
`EqualsBuilder`	`append(byte lhs, byte rhs)` Test if two `byte`s are equal.
`EqualsBuilder`	`append(char[] lhs, char[] rhs)` Deep comparison of array of `char`.
`EqualsBuilder`	`append(char lhs, char rhs)` Test if two `char`s are equal.
`EqualsBuilder`	`append(double[] lhs, double[] rhs)` Deep comparison of array of `double`.
`EqualsBuilder`	`append(double lhs, double rhs)` Test if two `double`s are equal by testing that the pattern of bits returned by `doubleToLong` are equal.
`EqualsBuilder`	`append(float[] lhs, float[] rhs)` Deep comparison of array of `float`.
`EqualsBuilder`	`append(float lhs, float rhs)` Test if two `float`s are equal byt testing that the pattern of bits returned by doubleToLong are equal.
`EqualsBuilder`	`append(int[] lhs, int[] rhs)` Deep comparison of array of `int`.
`EqualsBuilder`	`append(int lhs, int rhs)` Test if two `int`s are equal.
`EqualsBuilder`	`append(long[] lhs, long[] rhs)` Deep comparison of array of `long`.
`EqualsBuilder`	`append(long lhs, long rhs)` Test if two `long` s are equal.
`EqualsBuilder`	`append(Object[] lhs, Object[] rhs)` Performs a deep comparison of two `Object` arrays.
`EqualsBuilder`	`append(Object lhs, Object rhs)` Test if two `Object`s are equal using their `equals` method.
`EqualsBuilder`	`append(short[] lhs, short[] rhs)` Deep comparison of array of `short`.
`EqualsBuilder`	`append(short lhs, short rhs)` Test if two `short`s are equal.
`EqualsBuilder`	`appendSuper(boolean superEquals)` Adds the result of `super.equals()` to this builder.
`Boolean`	`build()` Returns `true` if the fields that have been checked are all equal.
`boolean`	`isEquals()` Returns `true` if the fields that have been checked are all equal.
`void`	`reset()` Reset the EqualsBuilder so you can use the same object again

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - EqualsBuilder
```
public EqualsBuilder()
```
    Constructor for EqualsBuilder.
    
    Starts off assuming that equals is true.
    
    See Also:
    
    Object.equals(Object)
- Method Detail
  - appendSuper
```
public EqualsBuilder appendSuper(boolean superEquals)
```
    Adds the result of super.equals() to this builder.
    
    Parameters:
    
    superEquals - the result of calling super.equals()
    
    Returns:
    
    EqualsBuilder - used to chain calls.
    
    Since:
    
    2.0
  - append
```
public EqualsBuilder append(Object lhs,
                            Object rhs)
```
    Test if two Objects are equal using their equals method.
    
    Parameters:
    
    lhs - the left hand object
    
    rhs - the right hand object
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(long lhs,
                            long rhs)
```
    Test if two long s are equal.
    
    Parameters:
    
    lhs - the left hand long
    
    rhs - the right hand long
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(int lhs,
                            int rhs)
```
    Test if two ints are equal.
    
    Parameters:
    
    lhs - the left hand int
    
    rhs - the right hand int
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(short lhs,
                            short rhs)
```
    Test if two shorts are equal.
    
    Parameters:
    
    lhs - the left hand short
    
    rhs - the right hand short
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(char lhs,
                            char rhs)
```
    Test if two chars are equal.
    
    Parameters:
    
    lhs - the left hand char
    
    rhs - the right hand char
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(byte lhs,
                            byte rhs)
```
    Test if two bytes are equal.
    
    Parameters:
    
    lhs - the left hand byte
    
    rhs - the right hand byte
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(double lhs,
                            double rhs)
```
    Test if two doubles are equal by testing that the pattern of bits returned by doubleToLong are equal.
    
    This handles NaNs, Infinities, and -0.0.
    
    It is compatible with the hash code generated by HashCodeBuilder.
    
    Parameters:
    
    lhs - the left hand double
    
    rhs - the right hand double
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(float lhs,
                            float rhs)
```
    Test if two floats are equal byt testing that the pattern of bits returned by doubleToLong are equal.
    
    This handles NaNs, Infinities, and -0.0.
    
    It is compatible with the hash code generated by HashCodeBuilder.
    
    Parameters:
    
    lhs - the left hand float
    
    rhs - the right hand float
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(boolean lhs,
                            boolean rhs)
```
    Test if two booleanss are equal.
    
    Parameters:
    
    lhs - the left hand boolean
    
    rhs - the right hand boolean
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(Object[] lhs,
                            Object[] rhs)
```
    Performs a deep comparison of two Object arrays.
    
    This also will be called for the top level of multi-dimensional, ragged, and multi-typed arrays.
    
    Parameters:
    
    lhs - the left hand Object[]
    
    rhs - the right hand Object[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(long[] lhs,
                            long[] rhs)
```
    Deep comparison of array of long. Length and all values are compared.
    
    The method append(long, long) is used.
    
    Parameters:
    
    lhs - the left hand long[]
    
    rhs - the right hand long[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(int[] lhs,
                            int[] rhs)
```
    Deep comparison of array of int. Length and all values are compared.
    
    The method append(int, int) is used.
    
    Parameters:
    
    lhs - the left hand int[]
    
    rhs - the right hand int[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(short[] lhs,
                            short[] rhs)
```
    Deep comparison of array of short. Length and all values are compared.
    
    The method append(short, short) is used.
    
    Parameters:
    
    lhs - the left hand short[]
    
    rhs - the right hand short[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(char[] lhs,
                            char[] rhs)
```
    Deep comparison of array of char. Length and all values are compared.
    
    The method append(char, char) is used.
    
    Parameters:
    
    lhs - the left hand char[]
    
    rhs - the right hand char[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(byte[] lhs,
                            byte[] rhs)
```
    Deep comparison of array of byte. Length and all values are compared.
    
    The method append(byte, byte) is used.
    
    Parameters:
    
    lhs - the left hand byte[]
    
    rhs - the right hand byte[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(double[] lhs,
                            double[] rhs)
```
    Deep comparison of array of double. Length and all values are compared.
    
    The method append(double, double) is used.
    
    Parameters:
    
    lhs - the left hand double[]
    
    rhs - the right hand double[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(float[] lhs,
                            float[] rhs)
```
    Deep comparison of array of float. Length and all values are compared.
    
    The method append(float, float) is used.
    
    Parameters:
    
    lhs - the left hand float[]
    
    rhs - the right hand float[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - append
```
public EqualsBuilder append(boolean[] lhs,
                            boolean[] rhs)
```
    Deep comparison of array of boolean. Length and all values are compared.
    
    The method append(boolean, boolean) is used.
    
    Parameters:
    
    lhs - the left hand boolean[]
    
    rhs - the right hand boolean[]
    
    Returns:
    
    EqualsBuilder - used to chain calls.
  - isEquals
```
public boolean isEquals()
```
    Returns true if the fields that have been checked are all equal.
    
    Returns:
    
    boolean
  - build
```
public Boolean build()
```
    Returns true if the fields that have been checked are all equal.
    
    Returns:
    
    true if all of the fields that have been checked are equal, false otherwise.
    
    Since:
    
    3.0
  - reset
```
public void reset()
```
    Reset the EqualsBuilder so you can use the same object again
    
    Since:
    
    2.5

Class EqualsBuilder

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

EqualsBuilder

Method Detail

appendSuper

append

append

append

append

append

append

append

append

append

append

append

append

append

append

append

append

append

append

isEquals

build

reset