Common Java Cookbook
Copyright © 2010 Tim O'Brien. All Rights Reserved.
Abstract
This collection provides expert tips for using Java-based utilities from projects such as Apache Commons, Apache Lucene, and Apache Velocity. You don't have to be an expert, the book's solution-based format contains code examples for a wide variety of web, XML, network, testing, and application projects. If you want to learn how to combine common open-source Java utilities to create powerful Java applications and tools, the Common Java Cookbook is for you.
- Copyright and License
- Foreword: 0.26
- Preface
- 1. Supplements to the Java 2 Platform
-
- 1.1. Introduction
- 1.1. Depending on Commons Lang
- 1.4. Automating the Generation of toString( ) Content
- 1.5. Customizing Generated toString( ) Content
- 1.6. Automating hashCode( ) and equals( )
- 1.7. Automating compareTo( )
- 1.8. Printing an Array
- 1.9. Cloning and Reversing Arrays
- 1.10. Transforming Between Object Arrays and Primitive Arrays
- 1.11. Finding Items in an Array
- 1.12. Creating a Map from a Multidimensional Array
- 1.13. Formatting Dates
- 1.14. Rounding Date Objects
- 1.15. Truncating Date Objects
- 1.16. Creating an Enum
- 1.18. Validation of Method Parameters
- 1.19. Measuring Time
- 2. Manipulating Text
-
- 2.1. Introduction
- 2.1. Setting Up StringUtils and WordUtils
- 2.2. Checking for an Empty String
- 2.3. Abbreviating Strings
- 2.4. Splitting a String
- 2.5. Finding Nested Strings
- 2.6. Stripping and Trimming a String
- 2.7. Chomping a String
- 2.8. Creating an Emphasized Header
- 2.9. Reversing a String
- 2.10. Wrapping Words
- 2.11. Testing the Contents of a String
- 2.12. Measuring the Frequency of a String
- 2.13. Parsing Formatted Strings
- 2.14. Calculating String Difference
- 2.15. Using Commons Codec
- 2.17. Calculating Soundex
- 3. JavaBeans
-
- 3.1. Introduction
- 3.2. Obtaining Commons BeanUtils
- 3.4. Accessing Simple Bean Properties
- 3.5. Accessing Nested Bean Properties
- 3.6. Accessing Indexed Bean Properties
- 3.7. Accessing Mapped Bean Properties
- 3.8. Accessing a Simple, Nested, Indexed, and Mapped Bean Property
- 3.9. Determining the Type of a Bean Property
- 3.10. Comparing Beans
- 3.11. Copying Bean Properties
- 3.12. Cloning a Bean
- 3.13. Setting a Bean Property
- 3.14. Testing Property Access
- 3.15. Validating Beans with Predicates
- 3.16. Creating a Map of Bean Properties
- 3.17. Wrapping a Bean with a Map
- 3.18. Creating a Dynamic Bean
- 3.19. Getting and Setting Properties as Strings
- 4. Functors
-
- 4.1. Introduction
- 4.1. Obtaining Commons Collections
- 4.3. Reversing a Comparator
- 4.4. Chaining Comparators
- 4.5. Comparing Nulls
- 4.6. Fixed-Order Comparison
- 4.7. Using Simple Predicates
- 4.8. Writing a Custom Predicate
- 4.9. Creating Composite Predicates
- 4.10. Transforming Objects
- 4.11. Creating a Chain of Transformations
- 4.12. Applying Conditional Transformations
- 4.13. Writing a Closure
- 4.14. Chaining Closures
- 4.15. Modeling Conditional Statements with Closures
- 4.16. Modeling Loops with Closures
- 5. Collections
-
- 5.1. Introduction
- 5.1. Obtaining Commons Collections
- 5.2. Using a Looping Iterator
- 5.3. Iterating Over an ArrayList
- 5.4. Filtering a Collection with a Predicate
- 5.5. Iterating Through Distinct Elements
- 5.6. Using a Bag
- 5.7. Using a Buffer
- 5.8. Creating a Priority Queue
- 5.9. Using a Blocking Buffer
- 5.10. Storing Multiple Values in a Map
- 5.11. Retrieving a Key by Value (Working with Bi-directional Maps)
- 5.12. Using a Case-Insensitive Map
- 5.13. Creating Typed Collections and Maps
- 5.14. Constraining Map Values
- 5.15. Constraining List Contents
- 5.16. Transforming Collections
- 5.17. Creating a Least Recently Used Cache
- 5.18. Using a Lazy Map
- 5.19. Counting Objects in a Collection
- 5.20. Performing Set Operations
- 5.21. Retrieving Map Values Without Casting
- 6. XML
-
- 6.1. Introduction
- 6.1. Obtaining Commons Digester
- 6.2. Turning XML Documents into Objects
- 6.3. Namespace-Aware Parsing
- 6.4. Creating a Simple XML Command Language
- 6.5. Variable Substitution and XML Parsing
- 6.6. Obtaining Commons Betwixt
- 6.7. Turning Beans into XML Documents
- 6.8. Customizing XML Generated from an Object
- 6.9. Turning XML Documents into Beans
- 7. Application Infrastructure
-
- 7.1. Introduction
- 1.1. Depending on Commons CLI
- 7.2. Parsing a Simple Command Line
- 7.3. Parsing a Complex Command Line
- 7.4. Printing Usage Information
- 1.1. Depending on Commons Configuration
- 7.6. Configuring Applications with Properties Files
- 7.7. Configuring Applications with XML
- 7.8. Using Composite Configuration
- 7.9. Depending on Commons Logging
- 7.10. Using an Abstract Logging Interface
- 7.11. Specifying a Logging Implementation
- 7.12. Depending on Apache Log4J
- 7.13. Configuring Log4J with a Properties File
- 7.14. Configuring Log4J with XML
- 8. Math
-
- 8.1. Introduction
- 8.1. Using Fractions
- 8.2. Finding the Maximum and Minimum in an Array
- 8.3. Using Number Ranges
- 8.4. Generating Random Variables
- 8.5. Obtaining Commons Math
- 8.6. Calculating Simple Univariate Statistics
- 8.7. Solving a System of Linear Equations
- 8.8. Arithmetic with Complex Numbers
- 8.9. Establishing Relationships Between Variables
- 8.10. Estimating the Amount of Time Left in a Process
- 9. Templating
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- 9.1. Introduction
- 9.1. Obtaining Commons JEXL
- 9.2. Using an Expression Language
- 9.3. Invoking Methods in an Expression
- 9.4. Externalizing Logic with an Expression Language
- 9.5. Obtaining Velocity
- 9.6. Using a Simple Templating Language
- 9.7. Writing Templates with Conditionals and Loops
- 9.8. Using Macros in a Templating Engine
- 9.9. Invoking Methods in a Template
- 9.10. Obtaining FreeMarker
- 9.11. Using a Complex Scripting Engine
- 9.12. Accessing XML Documents from a Templating Engine
- 9.13. Using Velocity in a Web Application
- 9.14. Using FreeMarker in a Web Application
- 10. I/O and Networking
-
- 10.1. Introduction
- 10.1. Obtaining Commons IO
- 10.2. Copying Streams, byte[ ], Readers, and Writers
- 10.3. Closing Streams, Readers, and Writers
- 10.4. Printing a Human-Readable File Size
- 10.5. Copying Files, Strings, and URLs
- 10.6. Deleting Directories Recursively
- 10.7. Obtaining the Size of a Directory
- 10.8. Touching a File
- 10.9. Filtering Files
- 10.10. Measuring Stream Traffic
- 10.11. Splitting an OutputStream
- 10.12. Obtaining Jakarta ORO
- 10.13. Using Globs and Perl5 Regular Expressions to List Files
- 10.14. Obtaining Commons Net
- 10.15. Writing an FTP Client
- 10.16. Sending Mail with SMTP
- 10.17. Checking a POP3 Mailbox
- 10.18. Testing an IP Address Against a Subnet
- 11. HTTP and WebDAV
-
- 11.1. Introduction
- 11.1. Obtaining HttpClient
- 11.3. Performing an HTTP GET
- 11.4. Sending Parameters in a Query String
- 11.5. Retrieving Content with a Conditional GET
- 11.6. Debugging HTTP Communications
- 11.7. Making an HTTP POST Request
- 11.8. Sending POST Data from a File
- 11.9. Uploading Files with a Multipart POST
- 11.10. Basic Authentication
- 11.11. NTLM Authentication
- 11.12. Working with Cookies
- 11.13. Handling Redirects
- 11.14. SSL
- 11.15. Accepting a Self-Signed Certificate
- 11.16. Obtaining Jakarta Slide
- 11.17. Connecting to WebDAV Resources
- 11.18. Modifying a WebDAV Resource
- 12. Searching and Filtering
-
- 12.1. Introduction
- 12.1. Obtaining Commons JXPath
- 12.2. Querying an Object Graph with XPath
- 12.3. Search a Collection of Simple Objects
- 12.4. Applying XPath Queries to Complex Object Graphs
- 12.5. Obtaining Lucene
- 12.6. Creating an Index of XML Documents
- 12.7. Searching for a Specific Term in a Document Index
- 12.8. Finding the Frequency of Terms in an Index
- 13. JSON
- 14. Protocol Buffers
- 15. Google Guava: I/O
-
- 15.1. Introduction
- 15.2. Obtaining Google Guava
- 15.3. Copying and InputStream to an OutputStream
- 15.4. Calculating a Checksum for a Byte Array
- 15.5. Calculating a Message Digest for a Byte Array
- 15.6. Concatenating Multiple Files
- 15.7. Concatenating Multiple Readers
- 15.8. Reading and Writing Byte Arrays to and from Memory
- 15.9. Slicing (and Dicing) an InputStream
- 15.10. Flushing and Closing Stream, Writer, or Reader (without the Headache of Exception Handling)
- 15.11. Measuring Amount of Data Written To and Read From a Stream
- 15.12. Buffering Data to a File As Needed
- 15.13. Appending Text to Files
- 15.14. Create Parent Directories (mkdir -p for Java)
- 15.15. Make a Temporary Directory
- 15.16. Delete Everything in a Directory
- 15.17. Recursively Delete Everything in a Directory (including Subdirectories)
- 15.18. Compare Two Files for Equality
- 15.19. Calculate the Checksum of a File
- 15.20. Calculate the Digest of a File
- 15.21. Map a File to Memory
- 15.22. Move a File
- 15.23. Create New InputStreams and OutputStreams for a File
- 15.24. Create New Readers and Writers for a File
- 15.25. Read Bytes from a File
- 15.26. Read Text from a File
- 15.27. Create a File
- 15.28. Overwrite a File
- 15.29. Convert a File to a Byte Array
- 15.30. Putting Limits on an InputStream
- 15.31. Discarding Bytes into the Abyss
- 15.32. Filtering Files by Regular Expression
- 16. Google Guava: Collections
-
- 16.1. Introduction
- 16.2. Obtaining Google Guava
- 16.3. Obtaining the Union of Two Sets
- 16.4. Obtaining the Intersection of Two Sets
- 16.5. Obtaining the Difference Between Two Sets
- 16.6. Obtaining the Symmetric Difference Between Two Sets
- 16.7. Generate All Possible Subsets of a Set
- 16.8. Working with Multisets
- 16.9. Retrieving a Key by Value (Working with Bi-directional Maps)
- 16.10. Adding Constraints to a Collection (List or Set)
- 16.11. Adding Constraints to a Map
- Index
List of Figures
- 1-1. Timeline of StopWatch.split( ) and unsplit( )
- 3-3. Structure of two simple beans: Book and Person
- 3-4. Diagram of the Apartment and Room beans
- 3-5. The Country, Region, and City beans
- 3-6. Objects involved in a sorting example
- 4-1. Logical expression to be modeled with Predicate
- 4-2. Circuit representing logical expression
- 4-3. Diagram of the joinArmy Transformer
- 4-4. A ChainedTransformer with two Transformers
- 4-5. A SwitchTransform with two Predicate instances, two Transformer instances, and a default Transformer
- 5-1. A FIFO buffer
- 5-2. Using a BlockingBuffer to create a pipeline
- 5-3. Venn diagrams for four set operations in CollectionUtils
- 8-1. Expression to be evaluated with Fraction
- 8-2. A system of linear equations
- 8-3. System of linear equations in Ax=B form
- 8-4. An unsolvable system of equations
- 8-5. Expressions evaluated with the Complex object
- 13.1. Transitive Dependencies for JSON-lib
- 14.1. Internet-scale Architecture from 2000
- 14.2. Internet-scale Architecture in 2010
- 14.3. Downloading Protocol Buffers Source
- 15.1. Using a FilebackedOutputStream to Store Data in Memory (or a File) Depending on Data Size
- 16.1. Calculating the Union of Two Sets
- 16.2. Calculating the Intersection of Two Sets
- 16.3. Calculating the Difference of Two Sets
- 16.4. Calculating the Symmetric Difference of Two Sets
- 16.5. Obtaining the entrySet() or the elementSet() from a Multiset
- 16.6. Generating the Inverse of a BiMap
- 16.7. Constraining a Collection
List of Examples
- 1.1. Adding a Dependency on Commons Lang
- 1-1. The PoliticalCandidate class using ReflectionToStringBuilder
- 1-2. Automating hashCode( ) and equals( )
- 1-3. Implementing compareTo( ) using a reflection builder
- 1-4. Customizing a compareTo( ) method with CompareToBuilder
- 1-5. Cloning and reversing a primitive array with ArrayUtils
- 1-6. Cloning and reversing an Object[ ] with ArrayUtils
- 1-7. Searching an array using ArrayUtils.contains( ) and ArrayUtils.indexOf( )
- 1-8. Creating a Map from an Object[ ][ ]
- 1-9. Truncating a Date object at Calendar.MONTH
- 1-10. Defining a Flavor enumeration by extending Enum
- 1-11. Extending ValuedEnum to create an enum
- 1-12. Vocalist bean with a PartEnum
- 1-13. Using public static final constants for category information
- 1-14. Simplifying with ValueEnum
- 1-18. Using Validate to perform simple validations
- 1-19. Using the Validator and the DoubleRange to validate method parameters
- 1-20. Using StopWatch to measure time
- 1-21. Using the StopWatch.split( ) and StopWatch.unsplit( ) methods
- 2.1. Adding a Dependency on Commons Codec
- 3-1. Sample bean
- 3.2. Adding a Dependency on Commons BeanUtils
- 3-4. A Person bean with two simple properties
- 3-5. Decorating a Comparator with a BeanComparator
- 3-6. BeanMap methods getBean( ), setBean( ), getType( ), getReadMethod( ), and getWriteMethod( )
- 3-7. Using BeanUtils to populate a bean from user input
- 4.1. Adding a Dependency on Commons Collections
- 4-1. A Comparator that compares Book objects by name and author
- 4-2. Using ReverseComparator to sort Book objects
- 4-3. A bean representing a playing card
- 4-4. Combining FixedOrderComparator with BeanComparator, NullComparator, and ComparatorChain
- 4-5. A simple Predicate implementation
- 4-6. Implementing the Predicate interface
- 4-7. InputPredicate: a predicate that selects an input from a Map
- 4-8. Implementing a multilevel composite Predicate
- 4-9. Using a SwitchTransformer
- 5.1. Adding a Dependency on Commons Collections
- 5-1. An EarthQuake bean
- 5-2. Major earthquake classification Predicate
- 5-3. Using a Bag to track inventory
- 5-4. Using a BoundedFifoBuffer
- 5-5. A Patient object
- 5-6. A Comparator to sort Patient objects by priority
- 5-7. Using a prioritizing buffer
- 5-8. A BufferListener constantly calling remove( )
- 5-9. An Indexer stage in a pipeline
- 5-10. Using MultiMap.remove( )
- 5-11. Storing ISO country codes in a BidiMap
- 5-12. Using a CaseInsensitiveMap for U.S. states
- 5-13. Using TypedList to decorate a list
- 5-14. Decorating a map with TypedMap
- 5-15. A Predicate to validate a Team's name property
- 5-16. Predicate to validate a Team's coach property
- 5-17. Example using a LazyMap
- 5-18. A StockQuoteTransformer
- 5-19. Using CollectionUtils union( ), intersection( ), disjunction( ), and subtract( )
- 6.1. Adding a Dependency on Commons Digester
- 6.2. Adding a Dependency on Commons Betwixt
- 7.1. Adding a Dependency on Commons CLI
- 7-1. Printing usage information with HelpFormatter
- 7.3. Adding a Dependency on Commons Configuration
- 7-2. global. properties
- 7-3. local .properties
- 7-4. user. properties
- 7.7. Adding a Dependency on Commons Logging
- 7.8. Adding a Dependency on Apache Log4J
- 8.1. Adding a Dependency on Commons Math
- 8-1. ProcessEstimator to estimate time of program execution
- 8-2. An example using the ProcessEstimator
- 9.1. Adding a Dependency on Commons JEXL
- 9.2. Adding a Dependency on Velocity
- 9.3. Adding a Dependency on Commons BeanUtils
- 10.1. Adding a Dependency on Commons IO
- 10.2. Adding a Dependency on Commons ORO
- 10.3. Adding a Dependency on Commons Net
- 10.4. Testing an IP Address against a Subnet
- 10.5. Printing Information about a Subnet
- 11.1. Adding a Dependency on Commons HttpClient
- 11-1. Requesting information with a conditional GET
- 11.3. Adding a Dependency on Slide
- 12.1. Adding a Dependency on Commons JXPath
- 12.2. Adding a Dependency on Lucene
- 12-1. PlayIndexer using Commons Digester and Apache Lucene
- 12-2. Digester rules for PlayIndexer
- 12-3. TermFreq finding the most frequent terms in an index
- 13.1. Adding a Dependency on Commons Digester
- 13.2. Generating JSON from Java
- 13.3. Converting a Map to JSON
- 13.4. Converting a Bean to JSON
- 13.5. Parsing JSON in Java
- 13.6. Adding Dependencies to Parse XML and Generate JSON
- 13.7. Converting XML to JSON
- 13.8. Adding Dependencies to Parse JSON and Generate XML
- 13.9. Converting JSON to XML
- 13.10. Generating XML from JSON without Type Hints
- 13.11. Supplying a Root Name to the XMLSerializer
- 13.12. Mesuring the Performance of Simple JSON Operations
- 14.1. Adding a Dependency on Commons Digester
- 14.2. A Protocol Buffers Message Definition
- 14.3. Encoding and Decoding a Protocol Buffers Message
- 14.4. Measuring Average Execution Time for Protocol Buffers Operations
- 15.1. Adding a Dependency on Google Guava
- 15.2. Copying the Contents of an InputStream to an OutputStream
- 15.3. Calculating the Checksum of a Byte Array
- 15.4. Calculating the MessageDigest of a Byte Array
- 15.5. Joining Two Files using ByteStreams.join() and ByteStreams.copy()
- 15.6. Joining Two Readers using CharStreams.join() and CharStreams.copy()
- 15.7. Using ByteArrayDataOutput and ByteArrayDataInput
- 15.8. Writing Data with the ByteArrayDataOutput Class
- 15.9. Writing Data without the ByteArrayDataOutput Class
- 15.10. Slicing Data from an InputStream
- 15.11. One of the Reasons Java Gets a Bad Rap
- 15.12. Using Closeables and Flushables in a finally block
- 15.13. Avoid Most Exception Handling with ByteStreams.write()
- 15.14. Using a CountingInputStream and CountingOutputStream
- 15.15. Measuring the Performance of FileBackedOutputStream
- 15.16. Appending Text to a File with Files.append()
- 15.17. Creating Subdirectories with File.createParentDirs()
- 15.18. Creating Nested Subdirectories using Files.createParentDirs()
- 16.1. Adding a Dependency on Google Guava
- 16.2. Using Sets.union() to Calculate the Union of Two Set Collections
- 16.3. Calculating the Intersection of Two Sets
- 16.4. Calculating the Difference Between Two Sets
- 16.5. Calculating the Symmetric Difference Between Two Sets
- 16.6. Generating all Possible Subsets of a Given Set
- 16.7. Using a Multiset
- 16.8. Using a BiMap
- 16.9. Defining a Custom Constraint
- 16.10. Adding Constraints to a Collection
- 16.11. Defining a custom MapConstraint
- 16.12. Validating entries as they are added to Map with MapConstraints.
