Table of Contents

• Chapter 1: Introduction to Java Streams 1
  • What is a Stream?1
  • Benefits of Using Streams2
  • Stream vs Collection3
  • Writing Your First Stream Example3
Chapter 2: Creating Streams 4
• Creating Streams from Collections4
• Creating Streams from Arrays5
• Creating Streams from Files and I/O6
• Generating Streams with Stream.of(), Stream.generate(), Stream.iterate()8
Chapter 3: Stream Operations Overview 9
• Intermediate vs Terminal Operations9
• Stream Laziness and Execution11
• Pipeline Construction and Processing12
Chapter 4: Basic Stream Operations 13
• Filtering Elements (filter())13
• Mapping Elements (map())15
• Sorting Elements (sorted())17
• Distinct Elements (distinct())19
• Limiting and Skipping Elements (limit(), skip())22
Chapter 5: Working with Primitive Streams 24
• IntStream, LongStream, DoubleStream24
• Conversion Between Object and Primitive Streams26
• Primitive Stream Operations and Examples28
Chapter 6: Collecting Stream Results 30
• Introduction to Collectors30
• Collecting to Lists, Sets, Maps31
• Joining Strings34
• Summary Statistics Collectors35
Chapter 7: Reducing and Aggregating Data 37
• Using reduce() for Aggregation37
• Common Reduction Patterns (sum, max, min)39
• Custom Reduction Operations42
Chapter 8: Optional and Streams 45
• Using Optional in Stream Pipelines45
• Handling Absent Values47
• Combining Streams and Optionals49
Chapter 9: Parallel Streams Basics 52
• Introduction to Parallel Streams52
• When to Use Parallel Streams54
• Example: Parallel vs Sequential Performance56
• Pitfalls and Thread Safety58
Chapter 10: Advanced Mapping Techniques 60
• FlatMapping with flatMap()60
• Mapping to Multiple Collections63
• Complex Transformations66
Chapter 11: Grouping and Partitioning Data 71
• Grouping with Collectors.groupingBy()71
• Multi-level Grouping74
• Partitioning with Collectors.partitioningBy()78
Chapter 12: Custom Collectors 81
• Writing Your Own Collector81
• Collector Interface Explained83
• Examples of Custom Collectors86
Chapter 13: Stream Composition and Pipelines 90
• Chaining Multiple Streams90
• Combining Streams with concat()93
• Stream Builders and Custom Stream Sources96
Chapter 14: Exception Handling in Streams 99
• Handling Checked Exceptions in Lambdas99
• Strategies for Robust Stream Pipelines102
• Examples with File I/O and Streams104
Chapter 15: Processing Text Files and Data Sources 107
• Reading and Processing CSV Files with Streams107
• Processing Large Text Files Efficiently110
• Example: Word Count with Streams112
Chapter 16: Working with Dates and Times in Streams 114
• Stream Operations on LocalDate, LocalDateTime114
• Filtering and Grouping by Date Fields117
• Practical Examples: Event Processing120
Chapter 17: Real-world Data Processing Examples 123
• Stream-Based Data Filtering and Reporting123
• Transforming and Exporting Data126
• Stream Processing in Web Applications129
Chapter 18: Performance Considerations and Best Practices 132
• Stream Performance Tips132
• Avoiding Common Pitfalls135
• When Not to Use Streams139
Chapter 19: Reactive Streams Introduction 141
• Overview of Reactive Programming141
• Differences Between Java Streams and Reactive Streams143
• Simple Examples Using Flow API (Java 9+)146
Chapter 20: Integrating Streams with Functional Programming 151
• Using Streams with Functional Interfaces151
• Composing Functions and Stream Pipelines153
• Currying and Partial Application Concepts156
Chapter 21: Debugging and Testing Stream Pipelines 158
• Debugging Techniques for Streams158
• Using Peek for Debugging160
• Unit Testing Streams with JUnit164