Advanced Java Roadmap
40 sections • 543 topics
- 1. Creating Lambda Syntax
- Example: Common lambda forms
- 2. Using Functional Interfaces (@FunctionalInterface)
- Example: Custom functional interface
- 3. Understanding Method References (::)
- 4. Using Constructor References (Class::new)
- Example: Stream toArray with constructor ref
- 5. Capturing Variables
- 6. Understanding Lambda Scope
- 7. Handling Exceptions in Lambdas
- Example: Wrapper utility
- 8. Using Lambda with Collections
- 9. Creating Custom Functional Interfaces
- Example: Tri-function
- 10. Composing Functions
- Example: Pipeline composition
- 11. Using Predicate Composition
- Example: Filter chain
- 12. Understanding Lambda Performance Characteristics
- 1. Creating Streams
- 2. Using Intermediate Operations
- 3. Using Terminal Operations
- 4. Understanding Stream Pipeline
- 5. Working with Primitive Streams
- Example: Avoid boxing
- 6. Using Collectors
- Example: Group + summarize
- 7. Creating Custom Collectors (Collector.of())
- Example: Top-N collector
- 8. Using Parallel Streams (parallelStream())
- 9. Understanding Stream Performance
- 10. Handling Infinite Streams
- 11. Using FlatMap for Nested Structures
- Example: Flatten orders
- 12. Debugging Streams (peek())
- 13. Using takeWhile() and dropWhile() (Java 9+)
- 14. Using Stream.toList() (Java 16+)
- 1. Creating Optional
- 2. Checking Presence
- 3. Retrieving Values
- 4. Throwing Exceptions (orElseThrow)
- 5. Transforming Values
- Example: Chained transform
- 6. Filtering Optional (filter)
- 7. Chaining Optional Operations
- 8. Using ifPresent (Consumer)
- 9. Using ifPresentOrElse (Java 9+)
- Example: Branching
- 10. Using or() for Alternative Optional (Java 9+)
- Example: Cascading lookups
- 11. Avoiding Common Pitfalls
- 12. Using Optional with Streams (stream() method)
- Example: Filter present values
- 1. Understanding Pure Functions
- 2. Using Function Composition
- Example: Pipeline
- 3. Understanding Higher-Order Functions
- 4. Using Currying and Partial Application
- Example: Currying
- 5. Implementing Tail Recursion
- Example: Trampoline
- 6. Using Memoization
- Example: Generic memoize
- 7. Understanding Lazy Evaluation
- 8. Working with Immutable Collections
- 9. Understanding Monads
- 10. Implementing Map-Reduce Patterns
- Example: Word count
- 11. Using Suppliers for Deferred Execution
- 1. Using LocalDate
- 2. Using LocalTime
- 3. Using LocalDateTime
- 4. Using ZonedDateTime
- 5. Using OffsetDateTime
- 6. Using Instant
- 7. Using Period and Duration
- 8. Formatting Dates (DateTimeFormatter)
- 9. Parsing Dates (parse())
- 10. Manipulating Dates
- 11. Using TemporalAdjusters
- Example: Next payday
- 12. Handling Time Zones
- 13. Converting Legacy Dates
- 1. Creating Generic Classes
- Example: Generic container
- 2. Creating Generic Methods
- 3. Using Bounded Type Parameters (<T extends>)
- 4. Using Wildcards (?, extends, super)
- 5. Understanding PECS Principle
- Example: PECS in Collections.copy
- 6. Using Multiple Bounds (<T extends A & B>)
- Example: Number + Comparable
- 7. Understanding Type Erasure
- 8. Using Recursive Type Bounds (<T extends Comparable<T>>)
- 9. Handling Generic Arrays
- 10. Using Raw Types
- 11. Understanding Reification vs Erasure
- 12. Working with Type Tokens (Class<T>)
- Example: Super-type token
- 1. Using Built-in Annotations
- 2. Creating Custom Annotations (@interface)
- Example: Custom annotation
- 3. Using Meta-Annotations
- 4. Setting Retention Policies
- 5. Defining Annotation Elements
- 6. Using Repeating Annotations (@Repeatable)
- 7. Processing Annotations at Runtime
- Example: Audit interceptor
- 8. Creating Type Annotations (@Target(TYPE_USE))
- 9. Understanding Annotation Inheritance
- 10. Using @SafeVarargs for Heap Pollution
- Example: Safe varargs
- 1. Understanding Annotation Processor Lifecycle
- 2. Creating AbstractProcessor Subclass
- Example: Skeleton
- 3. Using ProcessingEnvironment
- 4. Accessing RoundEnvironment
- 5. Generating Source Files (Filer)
- 6. Using JavaPoet for Code Generation
- Example: Generate hello class
- 7. Handling Compilation Errors (Messager)
- 8. Configuring Annotation Processors
- 9. Using Service Provider Interface
- 10. Debugging Annotation Processors
- 11. Understanding Incremental Processing
- 1. Getting Class Objects
- 2. Inspecting Class Members
- 3. Accessing Private Members (setAccessible)
- 4. Invoking Methods Dynamically (Method.invoke)
- 5. Creating Instances (Constructor.newInstance)
- 6. Modifying Field Values
- 7. Working with Annotations
- 8. Inspecting Generic Types (getGenericType)
- 9. Understanding Performance Implications
- 10. Using MethodHandles as Alternative
- Example: Lookup + invoke
- 1. Understanding MethodHandle API
- 2. Creating MethodHandles
- 3. Invoking MethodHandles
- 4. Using Method Types (MethodType)
- 5. Binding Methods (bindTo)
- 6. Creating Dynamic Call Sites
- 7. Understanding invokedynamic Instruction
- 8. Comparing MethodHandle vs Reflection
- 9. Using MethodHandles for Performance
- Example: Generated FI
- 10. Using VarHandle for Field Access
- 1. Creating VarHandles (lookup)
- 2. Using Atomic Operations
- 3. Using Memory Ordering
- 4. Accessing Array Elements Atomically
- 5. Accessing Field Values
- 6. Understanding Performance Benefits vs Atomic Classes
- 7. Using Fence Operations
- 8. Understanding Plain vs Opaque vs Volatile Access
- 9. Using VarHandle with Arrays
- Example: Lock-free counter array
- 10. Combining VarHandle with MethodHandle
- 1. Creating Record Classes
- Example: Basic record
- 2. Understanding Implicit Components
- 3. Adding Custom Methods
- 4. Using Compact Constructors
- Example: Compact validator
- 5. Implementing Interfaces with Records
- 6. Using Records with Generics
- Example: Generic Pair
- 7. Understanding Record Restrictions
- 8. Serializing Records
- 9. Using Records in Pattern Matching
- Example: Record patterns (Java 21+)
- 10. Understanding Record Performance
- 11. Using Local Records (Java 16+)
- Example: Local record in stream
- 1. Creating Sealed Classes
- Example: Sealed hierarchy
- 2. Using permits Clause
- 3. Understanding Subclass Modifiers
- 4. Using Sealed Interfaces
- 5. Understanding Exhaustiveness Checking
- 6. Using Sealed Classes with Pattern Matching
- Example: Exhaustive switch
- 7. Understanding Design Benefits
- 8. Combining Sealed Classes and Records
- Example: ADT
- 9. Understanding Reflection with Sealed Classes
- 10. Using Sealed Classes for Domain Modeling
- 1. Using Pattern Matching for instanceof (Java 16+)
- 2. Using Switch Expressions (Java 14+)
- Example: Switch expression
- 3. Using Pattern Matching in Switch (Java 21+)
- 4. Understanding Type Patterns
- 5. Using Guarded Patterns (when clause)
- Example: Guarded
- 6. Using Record Patterns (Java 21+)
- 7. Understanding Pattern Dominance
- 8. Using Null Patterns
- 9. Understanding Exhaustiveness in Switch
- 10. Combining Multiple Patterns
- 11. Using Deconstruction Patterns
- 1. Creating Text Blocks
- Example: Basic block
- 2. Understanding Indentation
- 3. Using Escape Sequences (\s, \)
- 4. Formatting Text Blocks
- 5. Using Text Blocks for JSON
- Example: JSON template
- 6. Using Text Blocks for SQL
- Example: SQL query
- 7. Using Text Blocks for HTML
- 8. Understanding Trailing Whitespace
- 9. Combining Text Blocks with String Methods
- 10. Using Text Blocks for XML Templates
- Example: SOAP envelope
- 11. Understanding Text Block Compilation
- 1. Using Switch Expressions
- 2. Using Local Variable Type Inference (var)
- 3. Understanding var with Lambdas
- 4. Using var in Try-with-Resources
- Example: var with resource
- 5. Using Private Interface Methods (Java 9+)
- 6. Using Default Methods in Interfaces
- 7. Using Static Methods in Interfaces
- 8. Using Enhanced Pseudo-Random Generators (Java 17+)
- 9. Using Modern String Methods
- 10. Using Collection Factory Methods
- 1. Creating Custom Exception Hierarchies
- Example: Domain hierarchy
- 2. Using Multi-Catch Blocks (Java 7+)
- 3. Using Try-with-Resources (AutoCloseable)
- 4. Handling Suppressed Exceptions (getSuppressed)
- 5. Understanding Exception Translation
- 6. Using Sneaky Throws Pattern
- Example: Sneaky throw
- 7. Wrapping Checked Exceptions in Lambdas
- Example: Wrapper
- 8. Creating Exception Handling Utilities
- 9. Using Result/Either Types for Functional Error Handling
- Example: Sealed Result
- 10. Understanding Stack Trace Manipulation
- 11. Understanding Exception Performance Implications
- 12. Using Chained Exceptions (initCause)
- 1. Creating Threads
- 2. Understanding Thread States
- 3. Understanding Thread Safety
- 4. Using synchronized Keyword
- 5. Understanding Volatile Keyword
- 6. Using wait() and notify() (Object methods)
- 7. Understanding Thread Interruption
- 8. Using Thread.join() (waiting for completion)
- 9. Understanding ThreadLocal Variables
- 10. Understanding Memory Consistency Errors
- 11. Setting Thread Priority (setPriority)
- 12. Using Daemon Threads (setDaemon)
- 1. Creating Thread Pools
- 2. Using ExecutorService Interface
- 3. Using Callable and Future
- 4. Configuring ThreadPoolExecutor
- 5. Using ScheduledExecutorService
- 6. Shutting Down Executors
- 7. Handling Rejected Tasks (RejectedExecutionHandler)
- 8. Using CompletionService
- 9. Understanding Fork/Join Framework
- Example: Sum array
- 10. Creating Custom ThreadFactory
- 11. Using Work-Stealing Pools
- 1. Creating CompletableFuture
- 2. Chaining Async Operations
- 3. Combining Futures
- 4. Handling Errors
- 5. Using Async Variants (thenApplyAsync)
- 6. Waiting for Completion
- 7. Combining Multiple Futures
- Example: Aggregate results
- 8. Using Custom Executors
- 9. Understanding Exception Propagation
- 10. Using CompletionStage Interface
- 11. Creating Timeout Handling
- Example: With timeout + fallback
- 1. Using ConcurrentHashMap
- 2. Using CopyOnWriteArrayList
- 3. Using CopyOnWriteArraySet
- 4. Using BlockingQueue Interface
- 5. Using LinkedBlockingQueue
- 6. Using ArrayBlockingQueue
- 7. Using PriorityBlockingQueue
- 8. Using ConcurrentLinkedQueue
- 9. Using ConcurrentSkipListMap
- 10. Understanding Performance Trade-offs
- 1. Using ReentrantLock
- Example: try/finally pattern
- 2. Using ReadWriteLock
- 3. Using StampedLock
- 4. Understanding Lock Fairness
- 5. Using Condition Variables
- 6. Using AtomicInteger and AtomicLong
- 7. Using AtomicReference (object atomicity)
- 8. Using AtomicBoolean
- 9. Understanding Compare-And-Swap (CAS)
- 10. Using LongAdder and LongAccumulator
- 11. Avoiding Deadlocks
- 12. Using Lock-Free Algorithms
- 1. Creating Virtual Threads (Thread.startVirtualThread)
- 2. Using Executors.newVirtualThreadPerTaskExecutor
- Example: Per-task executor
- 3. Using Thread.ofVirtual Builder
- 4. Understanding Virtual Thread Scheduling
- 5. Avoiding Pinning
- 6. Using Scoped Values
- 7. Understanding Performance Benefits
- 8. Migrating from Platform Threads
- 9. Debugging Virtual Threads
- 10. Understanding Carrier Threads
- 11. Using Virtual Threads with Blocking I/O
- 12. Understanding Structured Concurrency Integration
- 1. Using StructuredTaskScope API
- Example: Parallel fetch
- 2. Creating Scoped Tasks
- 3. Handling Task Failures
- 4. Using ShutdownOnFailure Policy
- 5. Using ShutdownOnSuccess Policy
- 6. Understanding Scope Lifecycle
- 7. Propagating Errors and Cancellation
- 8. Combining with Virtual Threads
- 9. Implementing Custom Task Scopes
- Example: Collect-all scope
- 10. Understanding Deadline Propagation
- 1. Using Path API
- 2. Working with Files API
- 3. Reading Files
- 4. Writing Files
- 5. Walking File Trees
- 6. Watching Directories (WatchService)
- Example: Watch directory
- 7. Using File Attributes
- 8. Working with Symbolic Links
- 9. Using Temporary Files and Directories
- 10. Understanding Memory-Mapped Files
- 11. Using FileSystem API
- Example: Read from ZIP
- 12. Using AsynchronousFileChannel
- 1. Using HttpClient API
- 2. Sending HTTP Requests
- Example: POST JSON
- 3. Handling HTTP Responses
- 4. Using Async HTTP Requests
- Example: Async with chain
- 5. Configuring HttpClient (timeouts, redirects, authenticators)
- 6. Working with WebSocket
- 7. Using ServerSocket and Socket
- 8. Using DatagramSocket
- 9. Configuring Socket Options
- 10. Using NIO Channels
- 11. Understanding Selectors
- 12. Implementing Non-Blocking Server
- Example: Selector loop
- 1. Implementing Serializable Interface
- 2. Using ObjectOutputStream and ObjectInputStream
- 3. Understanding serialVersionUID
- 4. Customizing Serialization
- 5. Using Externalizable Interface
- 6. Handling transient Fields
- 7. Understanding Serialization Security Risks
- 8. Using SerialVersionUID Best Practices
- 9. Implementing Custom Serialization Proxies
- Example: Serialization proxy
- 10. Understanding Deserialization Vulnerabilities
- 11. Using Serialization Filters (ObjectInputFilter)
- 1. Understanding module-info.java
- Example: module-info.java
- 2. Using requires Directive
- 3. Using exports Directive
- 4. Using opens Directive
- 5. Using Qualified Exports
- 6. Using requires transitive
- 7. Using provides and uses (ServiceLoader)
- 8. Creating Modular JARs
- 9. Using --module-path
- 10. Working with Automatic Modules
- 11. Migrating Legacy Code to Modules
- Migration Steps
- 12. Using jdeps for Module Analysis
- 1. Understanding Module Layers
- 2. Creating Custom Module Layers
- Example: Plugin layer
- 3. Using ModuleFinder API
- 4. Using ModuleDescriptor
- 5. Using Configuration API
- 6. Working with Layered Modules
- 7. Using ModuleReader
- 8. Implementing Module Resolution
- 9. Understanding Strong Encapsulation
- 10. Using --add-opens and --add-exports
- 11. Creating Modular Applications with jlink
- Example: jlink command
- 1. Understanding Class Loader Hierarchy
- 2. Using Bootstrap Class Loader
- 3. Using Platform Class Loader (Java 9+)
- 4. Using Application Class Loader
- 5. Understanding Parent Delegation Model
- 6. Creating Custom Class Loaders
- Example: Custom loader
- 7. Loading Classes Dynamically (Class.forName)
- 8. Understanding Class Initialization
- 9. Using Context Class Loader
- 10. Understanding Class Loader Isolation
- 11. Resolving Class Loading Issues
- 1. Understanding Java Agent Basics
- 2. Creating Java Agents
- Example: Premain agent
- 3. Using Instrumentation API
- 4. Transforming Classes (ClassFileTransformer)
- Example: Transformer
- 5. Retransforming Classes
- 6. Using Byte Buddy for Instrumentation
- 7. Using ASM Library
- 8. Attaching Agents at Runtime
- Example: Attach API
- 9. Profiling with Agents
- 10. Understanding Security Implications
- 1. Understanding Memory Areas
- 2. Understanding Heap Structure
- Heap Layout (Generational GC)
- 3. Understanding Young Generation
- 4. Understanding Object Allocation (TLAB)
- 5. Understanding Object Promotion
- 6. Using Memory Flags (-Xms, -Xmx, -XX:MetaspaceSize)
- 7. Understanding Escape Analysis
- 8. Understanding Native Memory (off-heap)
- 9. Understanding String Interning
- 10. Using Compressed OOPs (-XX:+UseCompressedOops)
- 11. Monitoring Memory Usage
- 12. Detecting Memory Leaks
- Leak-Hunting Workflow
- 1. Understanding GC Types
- 2. Using G1 Garbage Collector
- 3. Using Low-Latency GCs
- 4. Configuring GC Flags (-XX:+UseG1GC, -XX:+UseZGC)
- 5. Understanding GC Phases
- 6. Understanding Stop-The-World Events
- 7. Monitoring GC Activity
- 8. Tuning GC Parameters
- 9. Understanding Finalization
- 10. Using Cleaner API
- Example: Cleaner
- 11. Understanding Reference Types
- 12. Using Reference Queues
- Example: Phantom + queue
- 1. Using JVM Flags (-XX:+PrintFlagsFinal)
- 2. Using jcmd
- 3. Generating Heap Dumps (-XX:+HeapDumpOnOutOfMemoryError)
- 4. Using Thread Dumps
- 5. Analyzing GC Logs (-Xlog:gc)
- 6. Using JFR (Java Flight Recorder)
- 7. Using JMX (Java Management Extensions)
- 8. Profiling CPU Usage
- 9. Detecting Class Loading Issues
- 10. Understanding JIT Compilation (-XX:+PrintCompilation)
- 11. Using Mission Control for Analysis
- 1. Understanding JIT Compilation
- 2. Understanding Tiered Compilation
- 3. Using Inlining Optimization
- 4. Understanding Escape Analysis Optimization
- 5. Using StringBuilder for Concatenation
- 6. Minimizing Object Creation
- 7. Using Primitive Types vs Wrappers
- 8. Optimizing Collections
- 9. Using Lazy Initialization
- 10. Caching Expensive Operations
- 11. Understanding False Sharing
- 12. Using @Contended Annotation
- Example: Padding hot fields
- 13. Profiling Hotspots
- Hotspot Profiling Workflow
- 1. Setting Up JMH Project
- 2. Creating Benchmark Methods (@Benchmark)
- Example: Simple benchmark
- 3. Using Benchmark Modes
- 4. Configuring Warmup (@Warmup)
- 5. Configuring Measurement (@Measurement)
- 6. Using State Objects (@State)
- Example: State
- 7. Understanding Scope
- 8. Using Setup and TearDown (@Setup, @TearDown)
- 9. Avoiding Dead Code Elimination (Blackhole)
- Example: Blackhole
- 10. Running Benchmarks
- 11. Analyzing Results
- 12. Understanding JMH Pitfalls
- 1. Using Java Security Manager
- 2. Configuring Security Policies
- 3. Using Security Manager Alternatives (Java 17+)
- 4. Working with Cryptography (JCE)
- 5. Using MessageDigest
- Example: SHA-256
- 6. Using Cipher
- Example: AES-GCM
- 7. Working with KeyStore
- 8. Using SecureRandom
- 9. Implementing SSL/TLS Connections
- 10. Using JAAS (authentication, authorization)
- 11. Understanding Security Providers
- 12. Preventing Common Vulnerabilities
- 1. Understanding FFM API Basics
- 2. Managing Off-Heap Memory (MemorySegment)
- Example: Allocate and write
- 3. Using Arena for Memory Management
- 4. Defining Memory Layouts
- Example: Struct layout
- 5. Calling Native Functions (MethodHandle)
- Example: strlen call
- 6. Handling Pointers and Structs
- 7. Using jextract Tool
- 8. Understanding Safety Guarantees
- 9. Comparing with JNI
- 10. Understanding Performance Benefits
- 1. Using JDWP (Java Debug Wire Protocol)
- 2. Setting Breakpoints
- 3. Using Remote Debugging (-agentlib:jdwp)
- Example: Enable remote debug
- 4. Analyzing Stack Traces
- 5. Using Logging Frameworks
- 6. Enabling Assertions (-ea flag)
- 7. Using System.Logger API (Java 9+)
- Example: System.Logger
- 8. Debugging Multithreaded Applications
- 9. Using Memory Profilers
- 10. Detecting Performance Bottlenecks
- Bottleneck Diagnosis Workflow
- 11. Understanding Native Stack Traces
- 12. Using Debug Visualization Tools
- Summary