Symbol dictionaries allow a ArcGIS Runtime SDK for Java user to create filters or search keywords to find the appropriate symbol to display in a map, according to Developers.ArcGIS.com. A person can search for keywords in all symbols' metadata or use a filter search to find the correct symbol based on its geometry type, category, or StyleFile.
Prior to using the symbol dictionary, the developer must use code to set it up by selecting the dictionary type and calling the keyword and filter searching methods. Information and specific codes for creating and searching a symbol dictionary, as well as other resources for developers, are located at Developers.ArcGIS.com. The website additionally provides a code that can create sample codes for users as further examples of how to create and search through symbol dictionaries.
Symbol dictionaries are used in the ArcGIS Runtime SDK for Java program to control the symbology displayed, according to the ArcGIS website at Developers.ArcGIS.com. The purpose of the program is to convert messages from the military to military symbols, which are then added to map controls on computers. Every symbol on the map is collected in the symbol dictionary, which includes every possible symbol and its searchable metadata.