@MinLength Annotation With Reflection Validator
Custom @ValidRange Annotation and Validator
Reflectively Read and Modify Private Field
Populate Fields via Reflection
Reflection-Based copyProperties Utility
Reflection-Based @ValidateNotNull Validator
Reflection-Based @Inject Container
Dynamic Proxy Logging Wrapper
Reflection-Based Deep Cloner
Reflection-Based @ValidEmail Annotation
Total Spend Per Category With Streams
Average Salary by Department
Top 3 Highest-Paid Employees
Descending Union With Streams
Word Frequency With groupingBy
Flatten Nested Map to Dot Notation
Top Spender Per Category With Streams
Multi-Level Transaction Grouping With Streams
Custom Collector for Stream Aggregation
Stream CSV Into a Deduped Set
Bounded Parallelism With Custom ForkJoinPool
Custom Product Collector With Overflow
Custom Stream map Without .map()
Custom Collector for Std Dev or Median
Thread-Safe Counter: synchronized vs AtomicInteger
Alternating Odd/Even Printer With Two Threads
Thread-Safe Singleton With Double-Checked Locking
Producer-Consumer With Poison Pill
Thread-Safe Generic BlockingQueue
Build a Reentrant Lock From Scratch
Parallel Matrix Multiplication With Threads
Token-Bucket Rate Limiter
Instrumented Bounded ThreadPoolExecutor
Thread-Safe Generic Object Pool
Priority Job Scheduler With Thread Pool
Per-Type Concurrency Throttling Executor
Generics Type Safe Containers
Generic Repository With In-Memory Store
Bounded Wildcard Number Filter
Generic findMax With Bounded Type
Generic Pair and Mapping Method
Generic List Transformer With Wildcards
Generic Fixed-Capacity Circular Buffer
Custom Generic Iterable and Iterator
Generic Result<T,E> With map and flatMap
Generic Validator With Bounded Wildcards
Streaming Large Log File Processor
Directory Watcher for New JSON Files
Custom ClassLoader From Encrypted Bytes
External K-Way Merge Of Sorted Files
Fixed-Size LRU Cache With LinkedHashMap
Dynamic Function Pipeline Processor
Type-Safe Generic EventBus
Thread-Safe UserCache With Eviction
Reference-Equality Identity Map
Parallel URL Aggregator With CompletableFuture
Generic Retry Utility With Backoff
Thread-Safe Memoizing Function Wrapper
Non-Blocking CompletableFuture Fallback Chain
First Successful Future With Timeout
Parallel API Fan-Out With Timeouts
Error Handling Resilience
Custom Exception Hierarchy With Cause
Checked Exceptions in Stream.map()
AutoCloseable With Suppressed Exceptions
Circuit Breaker State Machine
Object Modeling Contracts
Correct equals() and hashCode()
Multi-Field Employee Comparator
Null-Safe Lookup With Optional
Immutable Class With Defensive Copies
Business Days Between Two Dates
Serialization Proxy Pattern
Object Resurrection via finalize()
Records Sealed Pattern Matching
Arithmetic Operation Enum
Credential Authenticator With Switch Patterns
Refactor instanceof Chain Into switch
Payment Modeling With Sealed Interfaces
Concurrency Stream Processing
Top 3 Merchants by Volume
Fail-Fast Task Runner With StructuredTaskScope
Parallel File Search With Fork/Join
Run 10,000 I/O Tasks With Virtual Threads