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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 instanceof MyClass == false) {
 return false;
 }
 if (this == obj) {
 return true;
 }
 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);
 }
 

Test if two long s are equal.

Deep comparison of array of long.

Deep comparison of array of int.

Deep comparison of array of short.

Deep comparison of array of char.

Deep comparison of array of byte.

Deep comparison of array of double.

Deep comparison of array of float.

Deep comparison of array of boolean.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields.

Constructor for EqualsBuilder.

Starts off assuming that equals is true.

Test if two Objects are equal using their equals method.

Test if two long s are equal.

Test if two ints are equal.

Test if two shorts are equal.

Test if two chars are equal.

Test if two bytes are equal.

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.

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.

Test if two booleanss are equal.

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.

Deep comparison of array of long. Length and all values are compared.

The method EqualsBuilder.append(long,long) is used.

Deep comparison of array of int. Length and all values are compared.

The method EqualsBuilder.append(int,int) is used.

Deep comparison of array of short. Length and all values are compared.

The method EqualsBuilder.append(short,short) is used.

Deep comparison of array of char. Length and all values are compared.

The method EqualsBuilder.append(char,char) is used.

Deep comparison of array of byte. Length and all values are compared.

The method EqualsBuilder.append(byte,byte) is used.

Deep comparison of array of double. Length and all values are compared.

The method EqualsBuilder.append(double,double) is used.

Deep comparison of array of float. Length and all values are compared.

The method EqualsBuilder.append(float,float) is used.

Deep comparison of array of boolean. Length and all values are compared.

The method EqualsBuilder.append(boolean,boolean) is used.

Adds the result of super.equals() to this builder.

Returns true if the fields that have been checked are all equal.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

Transient members will be not be tested, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be tested. Superclass fields will be included.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

Transient members will be not be tested, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be tested. Superclass fields will be included.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

Transient members will be not be tested, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be tested. Superclass fields will be included.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

If the TestTransients parameter is set to true, transient members will be tested, otherwise they are ignored, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be tested. Superclass fields will be included.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

If the testTransients parameter is set to true, transient members will be tested, otherwise they are ignored, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be included. Superclass fields will be appended up to and including the specified superclass. A null superclass is treated as java.lang.Object.

This method uses reflection to determine if the two Objects are equal.

It uses AccessibleObject.setAccessible to gain access to private fields. This means that it will throw a security exception if run under a security manager, if the permissions are not set up correctly. It is also not as efficient as testing explicitly.

If the testTransients parameter is set to true, transient members will be tested, otherwise they are ignored, as they are likely derived fields, and not part of the value of the Object.

Static fields will not be included. Superclass fields will be appended up to and including the specified superclass. A null superclass is treated as java.lang.Object.