Java bytecode stored in file is executed/interpreted by JVM (Java Virtual Machine). Bytecode files with .class extension are stored in memory, it is binary format and can be executable from JVM.
File Extension For Java Bytecode
The file extension name for a Java Bytecode File is .class
What is JVM and Java Bytecode File?
Java Virtual Machine (JVM) acts as a Runtime environment responsible for executing bytecode files, and Java bytecode files are compiled file that is generated by a Java Compiler (javac) from source code written in the Java programming language.
What is Different Between .class and .java File?
A .class file contains bytecodes and it is platform independent, you can move .class files from one platform to another, but .java file contains Java Source code and it can’t be moved from one platform to another platform as .class file.
How is .class File Generated?
A .class file can be generated from Java Source code by using javac.exe compiler provided by JDK. The javac compiler produces a .class file for each class in the program.
How to Use a .class File?
When you execute a program, the JVM loads your code, parses it, interprets it, and executes it. Each class file is loaded by JVM separately and if the program executes, it cannot be changed because the result is saved in class file.
What is the purpose of the .class file?
The .class file contains the code that your computer should interpret when you run a program. It comprises of a set of numerical instructions in binary form, also known as 'bytecode', which the Java Virtual Machine (JVM) understands.
What is the main difference between .class and .java files?
The main difference between .class and .java files is that the .class file contains the bytecodes and it is platform independent, but the .java file contains the Java Source code and can't be moved from one platform to another platform as a .class file.
What happens when Java source code is compiled?
When Java source code is compiled, it is converted into bytecode and written to a .class file. The bytecode contains instructions that JVM can read and interpret.
Is the .class file enough to run a program?
No. A Java program consists of one or more classes. Each class is compiled into its own .class file. All the .class files must be present when the Java program is executed.
How do I open a .class file?
Most .class files cannot be opened directly, as they are compiled and contain bytecode that can be interpreted by the Java Virtual Machine (JVM). You can use Java decompilers to decompile your code and view it in a readable format.
- Java Virtual Machine Tutorial: Find out more about what the JVM does and how it works
- Java Bytecode Explained: Read about the fundamentals of Java bytecode
- Using a Java Decompiler: Learn more about how you can use Java Decompilers to view .class files
- JVM Bytecode: A Deep dive into Class files: Learn more about the detailed structure of a Class File