QoS anonymous access permission verification extension point.
org.apache.dubbo.qos.permission.PermissionChecker
Dubbo QoS dubbo.application.qos-anonymous-access-permission-level anonymous access permission verification.
org.apache.dubbo.qos.permission.DefaultAnonymousAccessPermissionChecker
Maven project structure:
src
 |-main
    |-java
        |-com
            |-xxx
                |-XxxPermissionChecker.java (Implementing the PermissionChecker interface)
    |-resources
        |-META-INF
            |-dubbo
                |-org.apache.dubbo.qos.permission.PermissionChecker` (Plain text file, content: qosPermissionChecker=com.xxx.XxxPermissionChecker)
XxxPermissionChecker.java:
package com.xxx.qos.permission;
import org.apache.dubbo.qos.permission.PermissionChecker;
public class XxxAnonymousAccessPermissionChecker implements PermissionChecker {
    @Override
    public boolean access(CommandContext commandContext, PermissionLevel defaultCmdRequiredPermissionLevel) {
      // ...
    }
}
META-INF/dubbo/org.apache.dubbo.qos.permission.PermissionChecker:
qosPermissionChecker=com.xxx.XxxPermissionChecker