ValidationJoinPointFinalizer.java

/**
 * Copyright (c) 2009-2011 VMware, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.springsource.insight.plugin.springweb.validation;

import java.util.Collection;
import java.util.Collections;

import org.aspectj.lang.JoinPoint;
import org.springframework.validation.Errors;
import org.springframework.validation.ObjectError;

import com.springsource.insight.collection.method.JoinPointFinalizer;
import com.springsource.insight.intercept.InterceptConfiguration;
import com.springsource.insight.intercept.operation.Operation;
import com.springsource.insight.intercept.operation.OperationList;
import com.springsource.insight.intercept.operation.OperationMap;
import com.springsource.insight.intercept.operation.OperationUtils;
import com.springsource.insight.intercept.trace.FrameBuilder;
import com.springsource.insight.util.ListUtil;
import com.springsource.insight.util.StringUtil;

/**
 * Used to traverse the validation {@link Errors}
 */
public class ValidationJoinPointFinalizer extends JoinPointFinalizer {
    private static final InterceptConfiguration configuration = InterceptConfiguration.getInstance();
    private static final ValidationJoinPointFinalizer INSTANCE = new ValidationJoinPointFinalizer();
    /**
     * A {@link Number} value indicating the number of reported errors
     */
    public static final String ERRORS_COUNT = "validationErrorsCount";
    /**
     * Name of an <U>optional</U> {@link OperationList} that contains
     * the validation errors. Each error is encoded as an {@link OperationMap}
     * with a "name" entry that contains the object name and
     * a "value" entry that contains the error message.
     * <B>Note:</B> the list is created only if then number of errors is
     * <U>positive</U> and specific errors collection is enabled
     *
     * @see #ERRORS_COUNT
     * @see #collectExtraInformation()
     * @see OperationUtils#addNameValuePair(OperationList, String, String)
     */
    public static final String ERRORS_LIST = "validationErrorsList";
    /**
     * Maximum stored error text length
     */
    public static final int MAX_ERROR_TEXT_LENGTH = 96;

    private ValidationJoinPointFinalizer() {
        super();
    }

    public static final ValidationJoinPointFinalizer getInstance() {
        return INSTANCE;
    }

    public void registerValidationOperation(Operation op, JoinPoint jp) {
        registerWithSelf(op, jp);
    }

    @Override
    protected void populateOperation(Operation op, JoinPoint jp) {
        super.populateOperation(op, jp);

        Object[] args = jp.getArgs();
        populateOperation(op, (Errors) args[1], collectExtraInformation());
    }

    static final Operation populateOperation(Operation op, Errors errors, boolean collectErrorsList) {
        int numErrors = (errors == null) ? 0 : errors.getErrorCount();
        op.put(ERRORS_COUNT, numErrors);

        if ((numErrors > 0) && collectErrorsList) {
            populateOperation(op.createList(ERRORS_LIST), errors);
        }

        return op;
    }

    static final OperationList populateOperation(OperationList errList, Errors errors) {
        Collection<? extends ObjectError> errDetails = (errors == null)
                ? Collections.<ObjectError>emptyList()
                : errors.getAllErrors();
        if (ListUtil.size(errDetails) <= 0) {
            return errList;
        }

        for (ObjectError err : errDetails) {
            String objName = err.getObjectName();
            String objError = StringUtil.chopTailAndEllipsify(err.toString(), MAX_ERROR_TEXT_LENGTH);
            OperationUtils.addNameValuePair(errList, objName, objError);
        }

        return errList;
    }

    static final boolean collectExtraInformation() {
        return FrameBuilder.OperationCollectionLevel.HIGH.equals(configuration.getCollectionLevel());
    }
}