Expected 1Z0-819 Exam Topics, as suggested by Oracle :

• Module 1: Define and use fields and methods, including instance, static and overloaded methods/ Working with Arrays and Collections
• Module 2: Create and use subclasses and superclasses, including abstract classes/ Use local variable type inference, including as lambda parameters
• Module 3: Understand variable scopes, apply encapsulation and make objects immutable/ Connect to and perform database SQL operations, process query results using JDBC API
• Module 4: Handle text using String and StringBuilder classes/ Utilize polymorphism and casting to call methods, differentiate object type versus reference type
• Module 5: Implement serialization and deserialization techniques on Java objects/ Declare and instantiate Java objects including nested class objects
• Module 6: Create and use interfaces, identify functional interfaces/ Initialize objects and their members using instance and static initialiser statements and constructors
• Module 7: Deploy and execute modular applications, including automatic modules/ Implement functional interfaces using lambda expressions
• Module 8: Develop code that mitigates security threats such as denial of service/ Use Java Streams to filter, transform and process data
• Module  9: Use primitives and wrapper classes, including, operators, parentheses, type promotion and casting/ Sort collections and arrays using Comparator and Comparable interfaces
• Module 10: Secure resource access including filesystems, manage policies and execute privileged code/ Develop thread-safe code, using different locking mechanisms