The following code illustrates transferring data for one pixel from DataBuffer db1 , whose storage layout is described by MultiPixelPackedSampleModelmppsm1, to DataBuffer db2 , whose storage layout is described by MultiPixelPackedSampleModel mppsm2 . The transfer is generally more efficient than using getPixel or setPixel.

       MultiPixelPackedSampleModel mppsm1, mppsm2;
       DataBufferInt db1, db2;
       mppsm2.setDataElements(x, y, mppsm1.getDataElements(x, y, null,
                              db1), db2);
 

If obj is not null, it should be a primitive array of type TransferType. Otherwise, a ClassCastException is thrown. An ArrayIndexOutOfBoundsException is thrown if the coordinates are not in bounds, or if obj is not null and is not large enough to hold the pixel data.

The following code illustrates transferring data for one pixel from DataBuffer db1 , whose storage layout is described by MultiPixelPackedSampleModelmppsm1, to DataBuffer db2 , whose storage layout is described by MultiPixelPackedSampleModel mppsm2 . The transfer is generally more efficient than using getPixel or setPixel.

       MultiPixelPackedSampleModel mppsm1, mppsm2;
       DataBufferInt db1, db2;
       mppsm2.setDataElements(x, y, mppsm1.getDataElements(x, y, null,
                              db1), db2);
 

obj must be a primitive array of type TransferType. Otherwise, a ClassCastException is thrown. An ArrayIndexOutOfBoundsException is thrown if the coordinates are not in bounds, or if obj is not large enough to hold the pixel data.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.