Knowledge in jre components
Java Runtime Environment
Together, the Java Development Kit (JDK), the Java Virtual Machine (JVM), and the Java Runtime Environment (JRE) form a powerful trifecta of Java platform components for developing and running Java applications. Practically speaking, a runtime environment is a piece of software that is designed to run other software. As the runtime environment for Java, the JRE contains the Java class libraries, the Java class loader, and the Java Virtual Machine. In this system:The class loader is responsible for correctly loading classes and connecting them with the core Java class libraries.The JVM is responsible for ensuring Java applications have the resources they need to run and perform well in your device or cloud environment.The JRE is mainly a container for those other components, and is responsible for orchestrating their activities.What is a runtime environment?A software program needs to execute, and to do that it needs an environment to run in. The runtime environment loads class files and ensures there is access to memory and other system resources to run them. In the past, most software used the operating system (OS) as its runtime environment. The program ran inside whatever computer it was on, but relied on operating system settings for resource access. Resources in this case would be things like memory and program files and dependencies. The Java Runtime Environment changed all that, at least for Java programs.The Java Runtime EnvironmentWe can look at software as a series of layers that sit on top of the system hardware. Each layer provides services that will be used (and required) by the layers above it. The Java Runtime Environment is a software layer that runs on top of a computer's operating system, providing additional services specific to Java.The JRE smoothes over the diversity of operating systems, ensuring that Java programs can run on virtually any OS without modification. It also provides value-added services. Automatic memory management is one of the JRE's most important services, ensuring that programmers don't have to manually control the allocation and reallocation of memory.In short, the JRE is a sort of meta-OS for Java programs.How the JRE works with the JVMA Java Virtual Machine is a running software system responsible for executing live Java programs. The JRE is the on-disk system that takes your Java code, combines it with the necessary libraries, and starts the JVM to execute it.The JRE contains libraries and software that your Java programs need to run. As an example, the Java class loader is part of the Java Runtime Environment. This important piece of software loads compiled Java code into memory and connects the code to the appropriate Java class libraries.JRE consists of the following components:Deployment technologies, including deployment, Java Web Start and Java Plug-in.User interface toolkits, including Abstract Window Toolkit (AWT), Swing, Java 2D, Accessibility, Image I/O, Print Service, Sound, drag and drop (DnD) and input methods.Integration libraries, including Interface Definition Language (IDL), Java Database Connectivity (JDBC), Java Naming and Directory Interface (JNDI), Remote Method Invocation (RMI), Remote Method Invocation Over Internet Inter-Orb Protocol (RMI-IIOP) and scripting.Other base libraries, including international support, input/output (I/O), extension mechanism, Beans, Java Management Extensions (JMX), Java Native Interface (JNI), Math, Networking, Override Mechanism, Security, Serialization and Java for XML Processing (XML JAXP).Lang and util base libraries, including lang and util, management, versioning, zip, instrument, reflection, Collections, Concurrency Utilities, Java Archive (JAR), Logging, Preferences API, Ref Objects and Regular Expressions.Java Virtual Machine (JVM), including Java HotSpot Client and Server Virtual Machines.
kaushal shah
Components of the bridge
Components of the bridge
Syed Sadique Hussain