9.9. Java Security Manager

9.9.1. About the Java Security Manager

Java Security Manager
The Java Security Manager is a class that manages the external boundary of the Java Virtual Machine (JVM) sandbox, controlling how code executing within the JVM can interact with resources outside the JVM. When the Java Security Manager is activated, the Java API checks with the security manager for approval before executing a wide range of potentially unsafe operations.
The Security Manager uses a security policy to determine whether a given action will be permitted or denied.
Security Policy
A set of defined permissions for different classes of code. The Java Security Manager compares actions requested by applications against the security policy. If an action is allowed by the policy, the Security Manager will permit that action to take place. If the action is not allowed by the policy, the Security Manager will deny that action. The security policy can define permissions based on the location of code or on the code's signature.
The Security Manager and the security policy used are configured using the Java Virtual Machine options java.security.manager and java.security.policy.