@Target is a meta-annotation (an annotation used on other annotations) in Java that specifies the kinds of program elements to which an annotation type is applicable.It is defined in the package java.lang.annotation.Target Why is it used? By default, a custom annotation can be applied to any program element—classes, methods, fields, parameters, etc. The @Target annotation …
@Retention is a meta-annotation in Java that is used to indicate how long annotations with this annotation are to be retained.It is defined in the java.lang.annotation package and is applied to other annotations. This helps the compiler or JVM understand whether the annotation should be discarded at compile time, retained in the class file, or …
Annotations are categorized based on their purpose, definition, and runtime availability. Below is a detailed explanation of Annotation Types in tabular format with examples. Code Snippet for Each Annotation Type 1.Marker Annotation 2.Single-Value Annotation 3.Multi-Value Annotation 4.Custom Annotation Declaration 5.Meta-Annotation Annotations in Java provide a powerful way to add metadata to your code, which can …
Annotations are a special kind of metadata that you can add to Java code elements such as classes, methods, fields, and parameters. They provide information about the code but do not directly affect program execution. Important points about annotations: Metadata Provider:Annotations describe information about the code, like instructions or configurations, which can be used by …
The java.lang.annotation package is a core package in Java introduced in Java 5 that supports annotations, which are a powerful way to add metadata to Java code. This package is part of the java.lang package hierarchy and is used extensively in frameworks, libraries, and Java API design (like Spring, JPA, JUnit, etc.). What is an …
Dictionary is an abstract class in java.util (predecessor of Map interface).It represents a key-value pair data structure.It is obsolete and rarely used in favor of the Map interface (especially HashMap).Hashtable is a concrete subclass of Dictionary. Commonly Used Constructors and Methods Note: Dictionary uses Enumeration, not Iterator. Simple Program — Dictionary via Hashtable Output Problem …
The java.util.function package in Java provides a set of functional interfaces that facilitate functional programming by enabling the use of lambda expressions and method references. Introduced in Java 8 as part of the java.util package, these interfaces play a crucial role in making Java a more functional language, particularly for operations on collections, streams, and …
The java.util.jar package in Java is part of the java.util subpackage and provides classes for working with JAR (Java ARchive) files. JAR files are used to bundle multiple Java classes and associated metadata into a single archive file, which simplifies distribution and deployment of Java applications. Key Classes in java.util.jar JarFile: This class is used …
The java.util.zip package in Java provides classes for reading and writing standard ZIP and GZIP file formats. It’s part of the java.util package and includes a set of tools for compressing and decompressing data. This package is crucial for handling file compression and decompression operations in Java applications. Key Classes in java.util.zip ZipEntry: Represents a …
The java.util.spi package in Java provides Service Provider Interfaces (SPIs) that enable developers to extend the core Java platform’s functionality, particularly for internationalization and localization. These interfaces are used internally by the Java platform and can also be implemented by third-party libraries or developers to plug in custom locale-specific behavior for various services. Introduced in …
