This document discusses a tool called UJECTOR that can automatically generate executable Java code from UML diagrams, including class diagrams, sequence diagrams, and activity diagrams. UJECTOR takes UML diagrams as input and generates Java code as output. Automatic code generation from UML diagrams has benefits like reducing effort and being less error-prone than manual coding, but challenges include ensuring consistency of UML models and accuracy, maintainability, and efficiency of the generated code.