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How to understand the bytecode of Java? I believe many inexperienced people don't know what to do about it. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Bytecode is a set of highly optimized instructions designed to perform under a Java runtime system called the Java Virtual Machine (JavaVirtual Machine,JVM). In its standard form, JVM is a bytecode interpreter. This can be a bit surprising because languages such as C++ are compiled with executable code as a result. In fact, for performance reasons, many modern languages are designed to be compiled rather than interpreted. However, it is running Java programs through JVM that helps solve the main problem of downloading programs on Internet. This is why Java outputs bytecodes.

Translating a Java program into bytecode makes it easier to run the program in a wide range of environments. The reason is straightforward: just implement the Java virtual machine on a variety of platforms. In a given system, any Java program can run on a given system as long as the system runtime package exists. Remember: although the details of Java virtual machines vary from platform to platform, they all interpret the same Java bytecode. If a Java program is compiled to native code, there must be a corresponding version of the program for each CPU type connected to the Internet. This is certainly not a viable solution. Therefore, interpreting bytecode is the easiest way to write a truly portable program.

Interpreting the Java program also contributes to its security. Because each Java program runs under the control of the Java virtual machine, the Java virtual machine can contain the program and prevent it from causing side effects outside the system. As you will see, some limitations specific to the Java language enhance its security.

The program being interpreted usually does run slower than when the same program is compiled into executable code. But for Java, there is not much difference between the two. Using bytecode can make the programs of the Java runtime system execute much faster than you think.

Although Java is designed to interpret and execute programs, technically Java does not prevent bytecode from being dynamically compiled into native code. SUN provides a bytecode compiler, JIT (Just In Time, instant), in the Java 2 distribution. JIT is part of the Java virtual machine, which compiles bytecode into executable code in real time as needed. It cannot compile the entire Java order into executable code all at once, because Java performs various checks that are performed only at run time. It's important to keep this in mind because JIT compiles only the code it needs to run. However, this method of just-in-time compilation and execution still greatly improves performance. Even after the bytecode is compiled dynamically, the portability and security of the Java program can still be guaranteed, because the runtime system (which performs the compilation) can still control the running environment of the Java program. Whether the Java program is traditionally interpreted as bytecode or dynamically compiled into executable code, its function is the same.

After reading the above, have you mastered how to understand the bytecode of Java? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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