When you concatenate an executable and a JAR file:
- The operating system reads the initial part of the file (the executable header) and treats it as a binary executable.
- The JVM, on the other hand, looks for the ZIP file structure when attempting to load a JAR. Since the ZIP file format places its directory structure and central directory headers at the end of the file, the JVM can still recognize and load the JAR contents even when the ZIP file is appended to the executable.
As a result, the file can be executed as a binary by the operating system, while the JVM can also load and run it as a JAR file. This dual functionality is possible because the executable and JAR components operate independently of each other based on their respective file structures and headers.
When you concatenate an executable and a JAR file:
- The operating system reads the initial part of the file (the executable header) and treats it as a binary executable.
- The JVM, on the other hand, looks for the ZIP file structure when attempting to load a JAR. Since the ZIP file format places its directory structure and central directory headers at the end of the file, the JVM can still recognize and load the JAR contents even when the ZIP file is appended to the executable.
As a result, the file can be executed as a binary by the operating system, while the JVM can also load and run it as a JAR file. This dual functionality is possible because the executable and JAR components operate independently of each other based on their respective file structures and headers.