nullchecker.java

SUN的JAVA EE5源代码java_ee_sdk-5_03-preview-samples

/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the License).  You may not use this file except in
 * compliance with the License.
 *
 * You can obtain a copy of the license at
 * https://glassfish.dev.java.net/public/CDDLv1.0.html or
 * glassfish/bootstrap/legal/CDDLv1.0.txt.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * Header Notice in each file and include the License file
 * at glassfish/bootstrap/legal/CDDLv1.0.txt.
 * If applicable, add the following below the CDDL Header,
 * with the fields enclosed by brackets [] replaced by
 * you own identifying information:
 * "Portions Copyrighted [year] [name of copyright owner]"
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 */
package enterprise.annotation_override_interceptor_ejb;

import java.util.List;
import java.util.ArrayList;
import java.util.Map;

import java.lang.reflect.Method;

import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;

/**
 * This is the default interceptor
 */
public class NullChecker {

    @AroundInvoke
    public Object checkIfNull(InvocationContext ctx)
        throws Exception {

        Map<String, Object> ctxData = ctx.getContextData();
        List<String> interceptorNameList = (List<String>)
            ctxData.get("interceptorNameList");
        if (interceptorNameList == null) {
            interceptorNameList = new ArrayList<String>();
            ctxData.put("interceptorNameList", interceptorNameList);
        }

        //Now add this interceptor name to the list
        interceptorNameList.add("NullChecker");

        Method method = ctx.getMethod();
        Object param = ctx.getParameters()[0];
        if (param == null) {
            // An interceptor can throw any runtime exception or
            // application exceptions that are allowed in the
            // throws clause of the business method
            throw new BadArgumentException("Illegal argument: null");
        }

        // Proceed to the next interceptor OR business method
        return ctx.proceed();
    }

}