package org.springframework.security.oauth2.provider.expression;
   
   import org.aopalliance.intercept.MethodInvocation;
   import org.springframework.expression.ExpressionParser;
   import org.springframework.expression.spel.support.StandardEvaluationContext;
   import org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler;
   import org.springframework.security.core.Authentication;
   
   /**
   * <p>
   * A security expression handler that can handle default method security expressions plus the set provided by
   * {@link OAuth2SecurityExpressionMethods} using the variable oauth2 to access the methods. For example, the expression
   * <code>#oauth2.clientHasRole('ROLE_ADMIN')</code> would invoke {@link OAuth2SecurityExpressionMethods#clientHasRole}
   * </p>
   * <p>
   * By default the {@link OAuth2ExpressionParser} is used. If this is undesirable one can inject their own
   * {@link ExpressionParser} using {@link #setExpressionParser(ExpressionParser)}.
   * </p>
   * 
   * @author Dave Syer
   * @author Rob Winch
   * @see OAuth2ExpressionParser
   */
  public class OAuth2MethodSecurityExpressionHandler extends DefaultMethodSecurityExpressionHandler {
  
  	public OAuth2MethodSecurityExpressionHandler() {
  		setExpressionParser(new OAuth2ExpressionParser(getExpressionParser()));
  	}
  
  	@Override
  	public StandardEvaluationContext createEvaluationContextInternal(Authentication authentication, MethodInvocation mi) {
  		StandardEvaluationContext ec = super.createEvaluationContextInternal(authentication, mi);
  		ec.setVariable("oauth2", new OAuth2SecurityExpressionMethods(authentication));
  		return ec;
  	}
  }