Java Programming Environment,JDK,JRE,JVM.pptx

Java Programming Environment,JDK,JRE,JVM.pptx

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  Java Programming Environment Mrs.Sonali S.Patil AssistantProfessor, CSE Department,sharad institute of technology college of engineering yadrav
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  How Java programworks: This diagram will show you in detail description. 1)Java compiler will check syntax error. 2)Java interpreter will convert bytecode into native code. 3)After converting into native code or m/c code, we can able to see o/p into console.
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  Java Compiler andJava Interpreter: 1) Compiler • The process of converting entire source code into byte code that process is known as Java Compiler. • It is the program that contain set of instruction which is implemented in c/c++ programming language. 2)Interpreter • The process of converting byte code into native code, that process is known as Java interpreter.
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  What is JDKand JER? • What is JDK? • JDK is JAVA development kit, JDK contains JRE + Development tools such as JAVAC JAVA and JAVADOCS . • What is JRE? • JRE stands for Java Runtime Environment. It is a set of components to create and run a java application. JRE includes JVM, set of libraries, other files,& rt.jar.
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  What is JVM? •JVM stands for Java virtual Machine.  JVM is the Part of JRE.  JVM is Responsible to Load and Run Java Applications  JVM performs following tasks: • Loads the code • Verifies code • Execute code • Provides runtime environment • Provides library.
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  What is JVM?
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  What is JVM? 1)ClassLoaderSub System: • It loads all the classes into memory area. • ClassLoader Sub System is Responsible for the following 3 Activities. 1)Loading 2) Linking 3)Initialization 2) Memory Area: 1)Method area/class area 2)Heap Area 3)Stack Area 4)PC register 5)Native method stacks
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  What is JVM? 3)Execution Engine: • This is the Central Component of JVM. • Execution Engine is Responsible to Execute Java Class Files. • Execution Engine contains 2 Components for executing Java Classes. 1)Interpreter: • It is Responsible to Read Byte Code and Interpret (Convert) into Machine Code (Native Code) and Execute that Machine Code Line by Line. • The Problem with Interpreter is it Interpreters Every Time Even the Same Method Multiple Times. Which Reduces Performance of the System. • To Overcome this Problem SUN People Introduced JIT Compilers in 1.1 Version
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  What is JVM? 2)JIT compiler (Just in Time): • The Main Purpose of JIT Compiler is to Improve Performance. • Internally JIT Compiler Maintains a Separate Count for Every Method whenever JVM Come Across any Method Call. • JIT Compilation is Applicable Only for Repeatedly invoked Methods. But Not for Every Method • Java Native Interface (JNI): • An interface that allows java to interact with code written in another lang. • It acts as mediator for java method calls & the corresponding native lib. i.e. JNI is responsible to provide information about native libraries to the JVM. • Native method library provides or holds native lib. Information. • e.g. hashcode().