com.cronutils.model.Cron.java Source code

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Here is the source code for com.cronutils.model.Cron.java

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/*
 * Copyright 2014 jmrozanec
 * 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.cronutils.model;

import com.cronutils.mapper.CronMapper;
import com.cronutils.model.definition.CronConstraint;
import com.cronutils.model.definition.CronDefinition;
import com.cronutils.model.field.CronField;
import com.cronutils.model.field.CronFieldName;
import com.cronutils.model.field.expression.visitor.ValidationFieldExpressionVisitor;
import com.google.common.collect.Maps;
import org.apache.commons.lang3.Validate;

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

/**
 * Represents a cron expression
 */
public class Cron {
    private CronDefinition cronDefinition;
    private Map<CronFieldName, CronField> fields;
    private String asString;

    public Cron(CronDefinition cronDefinition, List<CronField> fields) {
        this.cronDefinition = Validate.notNull(cronDefinition, "CronDefinition must not be null");
        Validate.notNull(fields, "CronFields cannot be null");
        this.fields = Maps.newHashMap();
        for (CronField field : fields) {
            this.fields.put(field.getField(), field);
        }
    }

    /**
     * Retrieve value for cron field
     * @param name - cron field name.
     *             If null, a NullPointerException will be raised.
     * @return CronField that corresponds to given CronFieldName
     */
    public CronField retrieve(CronFieldName name) {
        return fields.get(Validate.notNull(name, "CronFieldName must not be null"));
    }

    /**
     * Retrieve all cron field values as map
     * @return unmodifiable Map with key CronFieldName and values CronField, never null
     */
    public Map<CronFieldName, CronField> retrieveFieldsAsMap() {
        return Collections.unmodifiableMap(fields);
    }

    public String asString() {
        if (asString == null) {
            ArrayList<CronField> fields = new ArrayList<CronField>(this.fields.values());
            Collections.sort(fields, CronField.createFieldComparator());
            StringBuilder builder = new StringBuilder();
            for (int j = 0; j < fields.size(); j++) {
                builder.append(String.format("%s ", fields.get(j).getExpression().asString()));
            }
            asString = builder.toString().trim();
        }
        return asString;
    }

    public CronDefinition getCronDefinition() {
        return cronDefinition;
    }

    public Cron validate() {
        for (Map.Entry<CronFieldName, CronField> field : retrieveFieldsAsMap().entrySet()) {
            CronFieldName fieldName = field.getKey();
            field.getValue().getExpression()
                    .accept(new ValidationFieldExpressionVisitor(
                            getCronDefinition().getFieldDefinition(fieldName).getConstraints(),
                            cronDefinition.isStrictRanges()));
        }
        for (CronConstraint constraint : getCronDefinition().getCronConstraints()) {
            if (!constraint.validate(this)) {
                throw new IllegalArgumentException(
                        String.format("Invalid cron expression: %s. %s", asString(), constraint.getDescription()));
            }
        }
        return this;
    }

    /**
     * Provides means to compare if two cron expressions are equivalent.
     * @param cronMapper - maps 'cron' parameter to this instance definition;
     * @param cron - any cron instance, never null
     * @return boolean - true if equivalent; false otherwise.
     */
    public boolean equivalent(CronMapper cronMapper, Cron cron) {
        return asString().equals(cronMapper.map(cron).asString());
    }

    /**
     * Provides means to compare if two cron expressions are equivalent.
     * Assumes same cron definition.
     * @param cron - any cron instance, never null
     * @return boolean - true if equivalent; false otherwise.
     */
    public boolean equivalent(Cron cron) {
        return asString().equals(cron.asString());
    }
}