JRE stands for JAVA RUNTIME ENVIRONMENT. JRE is a Subset of JDK. JRE is an Important Component of the Java Environment that Provides an Environment to execute the Java Program. JRE Actually exists as an Implementation of JVM. JRE is set libraries and other files that JVM uses at runtime. JVM performs that made by JRE.
Characteristics of JRE
ClassLoader: JRE Classloader runtime loads all classes necessary to run a java program. JRE uses Classloader to automate whenever required. Basically, Java Classes are Loaded into memory.
Bytecode verifier: The Bytecode Verifier checks the format and accuracy of Java Code and after that passes to the Interpreter. In this event, the code avoids the integrity or access rights, That set of the object will not be loaded. It will consider as Corrupted.
Interpreter: Successfully loaded bytecode loads, the java interpreter converts java bytecode to (.class file) that is easily understood by an operating System or the java interpreter create an instance of Java virtual machine that allows the Java program to be executed natively on underlying machine.
JRE is an Important Component of JDK. That provides the class libraries and other resources that specific java programs required for successful execution. In JRE java program have all the access and Functionalities they need and those work independently of the Operating System.
What Does JRE Contain?
JRE is the combination of a variety of other Supporting software tools and features that are most used fully in your Java Application.
Deployment Solution:
This is part of the JRE installation and deployment technologies like java Plugin and Java Web start that Simplify the activation of Applications and provide advanced Support for java updates.
Development Toolkits:
JRE has also contained toolkits designed that help developer improves their user Interface. There are some toolkits mentioned here:
- JAVA 2D: It’s an Application Programming Interface (API) used for drawing two – dimensional graphics in Java Language. With help of Java 2D Developer can create effective user Interfaces, Special effects, games, and Animation.
- Abstract Window Toolkit (AWT): It’s also an important tool of JRE. It is used to Create objects, buttons, Scrolls bars, and Windows.
- Swing: Swing is Another lightweight GUI that uses to create a set of widgets to offer flexible, user-friendly customizations. It also contains Components like Buttons Scroll bar, Text field, etc. we can Create a Graphical User Interface with help of Putting all components together.
Integration libraries:
JRE provides a number of integration libraries that help developers in creating seamless data connections between their applications and services. These are some libraries include:
- Java IDL (CORBA): In JRE its Use for Common Object Request Architecture to support distributed objects written in Java programming language.
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Java Database Connectivity (JDBC) API: JDBC Provides tools for developers to connect and execute query with databases, flat files, and spreadsheets. It’s part of JavaSE (Java Standard Edition). There are four types of drivers used by JDBC.
- JDBD-ODBC BridgeDriver,
- Native Driver,
- Network Protocol Driver
- Thin driver
- Java Naming and Directory Interface (JNDI): JNDI) is an application programming interface (API) and directory service that lets clients create portable applications that can fetch information from databases using naming conventions. With the Help of JNDI, we can discover and lookup resources via name.