Note for Java Programming - JAVA by Jeya Perumal

Topics ( 9 )

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JAVA 10 MARKS 1. Describe the following a. JDK b. JVM c. Web browser 1.Java Development Kit(JDK) The Java Development Kit (JDK) is an implementation of either one of the Java Platform, Standard Edition, Java Platform, Enterprise Edition, or Java Platform, Micro Edition platforms[1] released by Oracle Corporation in the form of a binary product aimed at Java developers on Solaris, Linux, macOS or Windows. The JDK includes a private JVM and a few other resources to finish the development of a Java Application.[2] Since the introduction of the Java platform, it has been by far the most widely used Software Development Kit (SDK).[citation needed] On 17 November 2006, Sun announced that they would release it under the GNU General Public License(GPL), thus making it free software. This happened in large part on 8 May 2007, when Sun contributed the source code to the OpenJDK.[3] Java Development Kit (JDK) Developer(s) Oracle Corporation Stable release 9.0.1 / 17 October 2017; 2 months ago Operating system Windows NT, macOS, Linux, Solaris Platform IA-32, x64, ARM, SPARC Type Software development kit License Sun License (most of it also under GPL) Website www.oracle.com/technetwork/java/index.html JDK contents The JDK has as its primary components a collection of programming tools, including: ▪ ▪ ▪ ▪ appletviewer – this tool can be used to run and debug Java applets without a web browser apt – the annotation-processing tool[4] extcheck – a utility that detects JAR file conflicts idlj – the IDL-to-Java compiler. This utility generates Java bindings from a given Java IDL file.

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▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ jabswitch – the Java Access Bridge. Exposes assistive technologies on Microsoft Windows systems. java – the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javaccompiler. Now a single launcher is used for both development and deployment. The old deployment launcher, jre, no longer comes with Sun JDK, and instead it has been replaced by this new java loader. javac – the Java compiler, which converts source code into Java bytecode javadoc – the documentation generator, which automatically generates documentation from source code comments jar – the archiver, which packages related class libraries into a single JAR file. This tool also helps manage JAR files. javafxpackager – tool to package and sign JavaFX applications jarsigner – the jar signing and verification tool javah – the C header and stub generator, used to write native methods javap – the class file disassembler javaws – the Java Web Startlauncher for JNLP applications JConsole – Java Monitoring and Management Console jdb – the debugger jhat – Java Heap Analysis Tool (experimental) jinfo – This utility gets configuration information from a running Java process or crash dump. (experimental) jmap Oracle jmap - Memory Map– This utility outputs the memory map for Java and can print shared object memory maps or heap memory details of a given process or core dump. (experimental) jmc – Java Mission Control jps – Java Virtual Machine Process Status Tool lists the instrumented HotSpot Java Virtual Machines (JVMs) on the target system. (experimental) jrunscript – Java command-line script shell. jstack – utility that prints Java stack traces of Java threads (experimental) jstat – Java Virtual Machinestatistics monitoring tool (experimental) jstatd – jstat daemon (experimental) keytool – tool for manipulating the keystore pack200 – JAR compression tool policytool – the policy creation and management tool, which can determine policy for a Java runtime, specifying which permissions are available for code from various sources. VisualVM – visual tool integrating several command-line JDK tools and lightweight[clarification needed]performance and memory profilingcapabilities wsimport – generates portable JAX-WS artifacts for invoking a web service. xjc – Part of the Java API for XML Binding (JAXB) API. It accepts an XML schema and generates Java classes. Experimental tools may not be available in future versions of the JDK. The JDK also comes with a complete Java Runtime Environment, usually called a private runtime, due to the fact that it is separated from the "regular" JRE and has extra contents. It consists of a Java Virtual Machine and all of the class libraries present in the

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production environment, as well as additional libraries only useful to developers, such as the internationalization libraries and the IDL libraries. Copies of the JDK also include a wide selection of example programs demonstrating the use of almost all portions of the Java API. Ambiguity between a JDK and an SDK The JDK forms an extended subset of a software development kit (SDK). It includes "tools for developing, debugging, and monitoring Java applications".[5]Oracle strongly suggests to now use the term JDK to refer to the Java SE Development Kit. The Java EE SDK is available with or without the JDK, by which they specifically mean the Java SE 7 JDK.[6] 2.JVM Java virtual machine "JRE" redirects here. For the podcast, see Joe Rogan Experience. A Java virtual machine (JVM) is an abstract computing machine that enables a computer to run a Java program. There are three notions of the JVM: specification, implementation, and instance. The specification is a document that formally describes what is required of a JVM implementation. Having a single specification ensures all implementations are interoperable. A JVM implementation is a computer program that meets the requirements of the JVM specification. An instance of a JVM is an implementation running in a process that executes a computer program compiled into Java bytecode. Java virtual machine Sun Microsystems Designer Bits 32-bit Introduced 1994 Type Endianness Stack and register–register Big

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Registers General purpose Per-method operand stack (up to 65535 operands) plus permethod local variables (up to 65535) Overview of a Java virtual machine (JVM) architecture based on The Java Virtual Machine Specification Java SE 7 Edition Java Runtime Environment (JRE) is a software package that contains what is required to run a Java program. It includes a Java Virtual Machine implementation together with an implementation of the Java Class Library. The Oracle Corporation, which owns the Java trademark, distributes a Java Runtime environment with their Java Virtual Machine called HotSpot. Java Development Kit (JDK) is a superset of a JRE and contains tools for Java programmers, e.g. a javac compiler. The Java Development Kit is provided free of charge either by Oracle Corporation directly, or by the OpenJDK open source project, which is governed by Oracle. 3.Web browser Usage share of web browsers according to StatCounter A web browser (commonly referred to as a browser) is a software application for retrieving, presenting and traversing information resources on the World Wide Web. An information