# How Do I: Map Data Types

When you are requesting or providing data from a Tuxedo buffer using the Tuxedo Control, you will need to understand how Java data types map to Tuxedo buffers. The Tuxedo Control does the mapping of the Java data types into and out of the Tuxedo buffers that are sent and received. The names of the arguments or fields in complex objects match up with their corresponding field names for FML/ FML32 and VIEW/VIEW32 buffers. Other buffer types simply concatenate all the fields into the buffers. Arrays map to occurrences of fields for FML and to VIEW arrays for VIEW.

The Tuxedo Control supports the following ATMI field types and maps them to the specified Java data types.

Java Data Type | Field Type
--- | ---
Short or short | FLD_SHORT
Integer or int | FLD_LONG
** Decimal | FLD_DECIMAL
Character or char | FLD_CHAR
Float or float | FLD_FLOAT
Double or double | FLD_DOUBLE
String | FLD_STRING
Byte[] or byte[] | FLD_CARRAY
* object | FLD_FML32

* This represents an instance of a class.

** This field type is only supported for View/View32 buffers.

Note: Decimal is a Java equivalent to the Tuxedo packed decimal type, dec_t. It is contained in the weblogic.wtc.jatmi package.