Introduction to Java 9

1 – Review of What is New in Java 9

• Overview of ‘smaller’ Java 9 topics
• Java versioning
• The JDK/JRE file structure
• Deprecation
• The jdeprscan tool
• Multi-Release JAR Files
• HTML 5 compliant JavaDoc
• Exercise: Creating a MRJar

2 – Milling Project Coin

• Changes made to the language since Java 6
• Multi-catch
• Using effectively final variables in try-with-resources
• Suppressed Exceptions
• Binary literals
• Reserved underscore (Java 9)
• Type inference in anonymous classes (Java 9)
• @SafeVargs (updates in Java 9)
• Default and static methods in interfaces (Java 8)
• Private methods in interfaces (Java 9)
• Exercise: Try-With-Resources

3 – Why JigSaw?

• Problems with Classpath
• Encapsulation and the public access modifier
• Application memory footprint
• Java 8’s compact profile
• Using internal JDK APIs

4 – Introduction to the Module System

• Introduce Project Jigsaw
• Classpath and Encapsulation
• The JDK internal APIs
• Java 9 Platform modules
• Defining application modules
• Define module dependencies
• Implicit dependencies
• Implied Readability
• Exporting packages
• Exercise: Defining Modules

5 – The Module Descriptor

• Define module requirements
• Explain qualified exports
• Open modules for reflection
• Use ServiceLoader
• The provides and uses keywords
• Exercise: Modules and the ServiceLoader
• Exercise: Using Reflection on modules

6 – Working with Modules

• Being backwards compatible
• The ModulePath and ClassPath
• Unnamed Modules
• Automatic Modules
• The JLink tool
• Exercise: Migrating to modules

7 – JShell

• Introduction to JShell
• Running Expressions in JShell
• Importing packages
• Defining methods and types
• Using the JShell editor
• Save and loading state
• Exercise: Working with JShell

8 – Other New Java 9 Features

• Enhancements on the Optional class
• Improvements made in the Process API
• The Stack-Walking API
• The HTTP2 Client
• The Multi-Resolution API
• Exercise: Working with Native processes
• Exercise: HTTP Clients

9 – Performance Optimizations

• Performance in Java 9
• Compact Strings
• String deduplication
• Ahead-Of-Time Compilation
• Hotspot Diagnostic commands
• The G1 Garbage collector
• Variable and Method Handles

10 – Multithreading

• Principles of Multithreading
• Creating a Threaded Class
• Basic Features of the Thread Class
• Thread Scheduling
• Thread Synchronization
• Exercise: Simple Thread Class
• Exercise: Simple Runnable Class

11 – Concurrent Java

• Concurrent Locks are Explicit and Flexible
• Executor Interfaces Provide Thread Management
• Challenges for Concurrent Use of Collections
• Concurrent Collections
• Atomic Variables Avoid Synchronization
• Exercise: Working with Concurrent Java
• Exercise: Sleeping Threads
• Exercise: Safe Data Access
• Exercise: Producer/Consumer

12 – Java 8 Concurrency Updates

• The common thread pool
• Atomic variables
• LongAdder and LongAccumulator
• CompletableFuture
• Non-blocking asynchronous tasks
• Exercise: CompletableFuture

13 – Introspection and Reflection

• Reflection classes
• Introspection
• Dynamic invocation of methods
• Using annotations
• Type annotations
• Receiver parameter
• Exercise: Introspection and Reflection
• Exercise: Reflection Server

14 – Reference Objects

• List the kinds of object references available in Java
• Introduce Weak, Soft and PhantomReference
• Explain the ReferenceQueue

15 – Objects, Declarations, and Initializations

• Abstraction and Responsibilities
• Low Coupling
• Programming principles
• Inheritance

16 – Exceptions

• Proper use of Exceptions
• Managing state in exceptional situations
• Checked vs. Unchecked Exceptions

17 – Profiling and Benchmarking

• List and describe the two types of benchmarks
• Describe the criteria that should be considered when constructing a benchmark plan
• Name the three most useful targets for profiling
• List four common tools/techniques for profiling
• Describe two strategies for improving performance as a result of profiling data
• List and explain the five most common problem areas for good performance with Java

18 – Profiling Tools

• Use the JDK to collect runtime profiling data
• Successfully read the profiling data generated by the JDK to detect performance bottlenecks
• Instrument your own code to collect method execution time data
• Exercise: Using the JVM Profiling Tools and Visual VM

19 – Code Optimization Techniques

• List three potential problems with strings
• List two ways to optimize loops
• Describe the advantages of private and final methods
• List two advantages of collections over vectors and hashtables
• List 4 other code and system optimizations
• Exercise: Code Optimizations

20 – Code Optimization Myths

• Debunk several myths of Java performance tuning
• Synchronization trade-offs
• Setting methods to be final
• String is not always bad
• Revisit the fundamentals of Java code performance
• How to detect a performance myth

21 – Design Optimization Techniques

• List five ways to optimize Java program design
• Exercise: Design Optimizations