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This page contains productive guides on important core Java built-in classes and their methods with examples.

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Newly Added Java API Guides

java.lang Package API/Methods Guides

java.lang - java.lang package provides classes that are fundamental to the design of the Java programming language.

java.util Package API/Methods Guides

java.util - java.util package contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes.

java.util.concurrent Package API/Methods Guides

java.util.concurrent -The java.util.concurrent package provides utility classes that are commonly useful in concurrent programming.

java.io Package API/Methods Guides

java.io - Java.io package provides classes for system input and output through data streams, serialization, and the file system.

java.time Package API/Methods Guides

java.time - Java 8 has introduced a new Date and Time API under java.time package. The java.time package provides API for dates, times, instants, and durations.

java.sql Package API/Methods Guides

java.sql - The java.sql package provides the API for accessing and processing data stored in a data source (usually a relational database) using the Java programming language.

java.lang.reflect Package API/Methods Guides

java.lang.reflect - java.lang.reflect package provides classes and interfaces that are used to obtain reflective information about classes and objects.

java.math Package API/Methods Guides

java.math - java.math package provides classes for performing arbitrary-precision integer arithmetic (BigInteger) and arbitrary-precision decimal arithmetic (BigDecimal).

java.nio.file Package API/Methods Guides

java.nio.file - java.nio.file package defines interfaces and classes for the Java virtual machine to access files, file attributes, and file systems.