Java Language
- Getting started with Java Language
- Top 10 Java Errors with Solutions
- Awesome Book
- Awesome Community
- Awesome Course
- Awesome Tutorial
- Awesome YouTube
- 2D Graphics in Java
- Alternative Collections
- Annotations
- Apache Commons Lang
- AppDynamics and TIBCO BusinessWorks Instrumentation for Easy Integration
- Applets
- Arrays
- Asserting
- Atomic Types
- Audio
- Autoboxing
- Basic Control Structures
- Benchmarks
- BigDecimal
- BigInteger
- Bit Manipulation
- BufferedWriter
- ByteBuffer
- Bytecode Modification
- C++ Comparison
- Calendar and its Subclasses
- Character encoding
- Choosing Collections
- Class - Java Reflection
- Classes and Objects
- Classloaders
- Collection Factory Methods
- Collections
- Command line Argument Processing
- Common Java Pitfalls
- Comparable and Comparator
- CompletableFuture
- Concurrent Collections
- Concurrent Programming (Threads)
- Console I/O
- Constructors
- Converting to and from Strings
- Creating Images Programmatically
- Currency and Money
- Date Class
- Dates and Time (java.time.*)
- Default Methods
- Dequeue Interface
- Disassembling and Decompiling
- Documenting Java Code
- Dynamic Method Dispatch
- Encapsulation
- Enum Map
- Enum starting with number
- Enums
- EnumSet class
- Exceptions and exception handling
- Executor, ExecutorService and Thread pools
- Expressions
- File I/O
- FileUpload to AWS
- Fluent Interface
- FTP (File Transfer Protocol)
- Functional Interfaces
- Generating Java Code
- Generics
- Getters and Setters
- Hashtable
- HttpURLConnection
- Immutable Class
- Immutable Objects
- Inheritance
- InputStreams and OutputStreams
- Installing Java (Standard Edition)
- Interfaces
- Iterator and Iterable
- Java Agents
- Java Compiler - 'javac'
- Java deployment
- Java Editions, Versions, Releases and Distributions
- Java Floating Point Operations
- Java Memory Management
- Java Memory Model
- Java Native Access
- Java Native Interface
- Java Performance Tuning
- Java Pitfalls - Exception usage
- Java Pitfalls - Language syntax
- Java Pitfalls - Nulls and NullPointerException
- Java Pitfalls - Performance Issues
- Java Pitfalls - Threads and Concurrency
- Java plugin system implementations
- Java Print Service
- Java SE 7 Features
- Java SE 8 Features
- Java Sockets
- Java Virtual Machine (JVM)
- JavaBean
- JAXB
- JAX-WS
- JMX
- JNDI
- JShell
- JSON in Java
- Just in Time (JIT) compiler
- JVM Flags
- JVM Tool Interface
- Lambda Expressions
- LinkedHashMap
- List vs SET
- Lists
- Literals
- Local Inner Class
- Localization and Internationalization
- LocalTime
- log4j / log4j2
- Logging (java.util.logging)
- Maps
- Modules
- Multi-Release JAR Files
- Nashorn JavaScript engine
- Nested and Inner Classes
- Networking
- New File I/O
- NIO - Networking
- Non-Access Modifiers
- NumberFormat
- Object Class Methods and Constructor
- Object Cloning
- Object References
- Operators
- Optional
- Oracle Official Code Standard
- Annotations
- Braces
- Class Structure
- Import statements
- Indentation
- Java Source Files
- Lambda Expressions
- Literals
- Modifiers
- Naming Conventions
- Package declaration
- Redundant Parentheses
- Special Characters
- Variable Declarations
- Whitespace
- Wrapping Expressions
- Wrapping Method Declarations
- Wrapping statements
- Packages
- Parallel programming with Fork/Join framework
- Polymorphism
- Preferences
- Primitive Data Types
- Process
- Properties Class
- Queues and Deques
- Random Number Generation
- Readers and Writers
- Recursion
- Reference Data Types
- Reference Types
- Reflection API
- Regular Expressions
- Remote Method Invocation (RMI)
- Resources (on classpath)
- RSA Encryption
- Runtime Commands
- Scanner
- Secure objects
- Security & Cryptography
- Security & Cryptography
- SecurityManager
- Serialization
- ServiceLoader
- Sets
- Singletons
- Sockets
- SortedMap
- Splitting a string into fixed length parts
- Stack-Walking API
- Streams
- String Tokenizer
- StringBuffer
- StringBuilder
- Strings
- sun.misc.Unsafe
- super keyword
- The Classpath
- The Java Command - 'java' and 'javaw'
- The java.util.Objects Class
- ThreadLocal
- TreeMap and TreeSet
- Type Conversion
- Unit Testing
- Using Other Scripting Languages in Java
- Using the static keyword
- Using ThreadPoolExecutor in MultiThreaded applications.
- Varargs (Variable Argument)
- Visibility (controlling access to members of a class)
- WeakHashMap
- XJC
- XML Parsing using the JAXP APIs
- XML XPath Evaluation
- XOM - XML Object Model
Java Language Oracle Official Code Standard Import statements
Example
// First java/javax packages
import java.util.ArrayList;
import javax.tools.JavaCompiler;
// Then third party libraries
import com.fasterxml.jackson.annotation.JsonProperty;
// Then project imports
import com.example.my.package.ClassA;
import com.example.my.package.ClassB;
// Then static imports (in the same order as above)
import static java.util.stream.Collectors.toList;
-
Import statements should be sorted…
- …primarily by non-static / static with non-static imports first.
- …secondarily by package origin according to the following order
- java packages
- javax packages
- external packages (e.g. org.xml)
- internal packages (e.g. com.sun)
- …tertiary by package and class identifier in lexicographical order
-
Import statements should not be line wrapped, regardless of whether it exceeds the recommended maximum length of a line.
-
No unused imports should be present.
Wildcard imports
- Wildcard imports should in general not be used.
- When importing a large number of closely-related classes (such as implementing a visitor over a tree with dozens of distinct “node” classes), a wildcard import may be used.
- In any case, no more than one wildcard import per file should be used.
