How to Resolve java/lang/NoClassDefFoundError: java/lang/Object in JRE 1.7?

What causes the java/lang/NoClassDefFoundError: java/lang/Object error in JRE 1.7, and how can it be resolved?

Error occurred during initialization of VM
java/lang/NoClassDefFoundError: java/lang/Object

The `java/lang/NoClassDefFoundError` indicates that the Java Virtual Machine (JVM) is unable to find the `java.lang.Object` class, essential for running any Java program. This error can stem from several underlying issues related to incorrect Java configurations or missing files.

# Verifying JAVA_HOME
echo $JAVA_HOME
# Verifying PATH
echo $PATH
# Checking Java version
java -version

Causes

• Incorrect JAVA_HOME and PATH settings.
• Corrupted or missing `rt.jar`, which contains core Java classes.
• Running a 32-bit Java application on a 64-bit JVM or the other way around.
• Executing Java binaries without proper permissions.

Solutions

• Verify that JAVA_HOME points to the correct Java installation and includes the `/bin` directory in the system PATH.
• Ensure `rt.jar` file exists in `<JAVA_HOME>/jre/lib` directory. If it's missing, consider reinstalling Java.
• Confirm that the Java version matches the architecture of your application (32-bit vs 64-bit).
• Check file permissions for the Java installation directory and ensure your user has access.

Mistake: JAVA_HOME not set correctly or pointing to an outdated version.

Solution: Make sure JAVA_HOME points to your current JRE or JDK installation.

Mistake: PATH environment variable doesn’t include the Java bin directory.

Solution: Add `<JAVA_HOME>/bin` to your system's PATH.

Mistake: Using a 32-bit version of Java with a 64-bit application, or vice versa.

Solution: Install the correct version of Java that matches your application's architecture.