com.adaptris.core.services.cache.CacheEntryEvaluator.java Source code

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Here is the source code for com.adaptris.core.services.cache.CacheEntryEvaluator.java

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/*
 * Copyright 2018 Adaptris Ltd.
 * 
 * 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.adaptris.core.services.cache;

import javax.validation.Valid;

import org.apache.commons.lang.BooleanUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.adaptris.annotation.AdvancedConfig;
import com.adaptris.annotation.DisplayOrder;
import com.adaptris.annotation.InputFieldDefault;
import com.adaptris.annotation.InputFieldHint;
import com.adaptris.core.AdaptrisMessage;
import com.adaptris.core.CoreException;
import com.adaptris.core.ServiceException;
import com.adaptris.core.util.Args;
import com.thoughtworks.xstream.annotations.XStreamAlias;

/**
 * Evaluates cache keys and values for the various cache services.
 * 
 * @config cache-entry-evaluator
 */
@XStreamAlias("cache-entry-evaluator")
@DisplayOrder(order = { "friendlyName", "keyTranslator", "valueTranslator", "errorOnEmptyKey",
        "errorOnEmptyValue" })
public class CacheEntryEvaluator {
    private transient Logger log = LoggerFactory.getLogger(this.getClass());

    @InputFieldDefault(value = "true")
    @AdvancedConfig
    private Boolean errorOnEmptyKey;
    @InputFieldDefault(value = "true")
    @AdvancedConfig
    private Boolean errorOnEmptyValue;
    @Valid
    private CacheKeyTranslator keyTranslator;
    @Valid
    private CacheValueTranslator valueTranslator;
    @AdvancedConfig
    @InputFieldHint(style = "BLANKABLE")
    private String friendlyName;

    public CacheEntryEvaluator() {

    }

    protected String getKey(AdaptrisMessage msg) throws ServiceException {

        String value = null;
        try {
            value = keyTranslator().getKeyFromMessage(msg);
            if (value == null && errorOnEmptyKey()) {
                throw new ServiceException("Null cache-key returned");
            }
        } catch (Exception e) {
            rethrow(e, "cache-key");
        }
        return value;
    }

    protected Object getValue(AdaptrisMessage msg) throws ServiceException {
        Object value = null;
        try {
            value = valueTranslator().getValueFromMessage(msg);
            if (value == null && errorOnEmptyValue()) {
                throw new ServiceException("Null cache-value returned");
            }
        } catch (Exception e) {
            rethrow(e, "cache-value");
        }
        return value;
    }

    private void rethrow(Exception e, String type) throws ServiceException {
        if (e instanceof ServiceException) {
            throw (ServiceException) e;
        } else {
            log.warn("Unable to generate {}:{}", type, e.getMessage());
            log.trace(e.getMessage(), e);
        }
    }

    /**
     * Throw an error if we cannot look up the Key value
     *
     * @param bool default is true.
     */
    public void setErrorOnEmptyKey(Boolean bool) {
        errorOnEmptyKey = bool;
    }

    public Boolean getErrorOnEmptyKey() {
        return errorOnEmptyKey;
    }

    boolean errorOnEmptyKey() {
        return BooleanUtils.toBooleanDefaultIfNull(getErrorOnEmptyKey(), true);
    }

    /**
     * Throw an error if we cannot look up the Value to be stored in the cache
     *
     * @param bool default is true.
     */
    public void setErrorOnEmptyValue(Boolean bool) {
        errorOnEmptyValue = bool;
    }

    public Boolean getErrorOnEmptyValue() {
        return errorOnEmptyValue;
    }

    boolean errorOnEmptyValue() {
        return BooleanUtils.toBooleanDefaultIfNull(getErrorOnEmptyValue(), true);
    }

    /**
     * Sets the translator to use to extract the Key value from the message
     *
     * @param translator default is null.
     */
    public void setKeyTranslator(CacheKeyTranslator translator) {
        keyTranslator = Args.notNull(translator, "keyTranslator");
    }

    /**
     * Get the configured key translator.
     *
     * @return the configured key translator.
     */
    public CacheKeyTranslator getKeyTranslator() {
        return keyTranslator;
    }

    /**
     * Get the key translator.
     *
     * @return the configured key translator via {@link #setKeyTranslator(CacheKeyTranslator)} or a default translator if null.
     */
    public CacheKeyTranslator keyTranslator() {
        return getKeyTranslator() != null ? getKeyTranslator() : new NullCacheTranslator();
    }

    /**
     * Sets the translator to extract the Value to be stored in the cache
     * 
     * @param translator default is null.
     */
    public void setValueTranslator(CacheValueTranslator translator) {
        valueTranslator = Args.notNull(translator, "valueTranslator");
    }

    /**
     * Get the configured value translator.
     *
     * @return the configured value translator.
     */
    public CacheValueTranslator getValueTranslator() {
        return valueTranslator;
    }

    /**
     * Get the value translator.
     *
     * @return the configured key translator via {@link #setValueTranslator(CacheValueTranslator)} or a default translator if null.
     */
    public CacheValueTranslator valueTranslator() {
        return getValueTranslator() != null ? getValueTranslator() : new NullCacheTranslator();
    }

    public String getFriendlyName() {
        return friendlyName;
    }

    /**
     * Set the name of this cache entry generator for logging purposes.
     *
     * @param name
     */
    public void setFriendlyName(String name) {
        friendlyName = name;
    }

    public String friendlyName() {
        return getFriendlyName() == null ? this.getClass().getSimpleName() : getFriendlyName();
    }

    private class NullCacheTranslator implements CacheValueTranslator, CacheKeyTranslator {

        @Override
        public Object getValueFromMessage(AdaptrisMessage msg) throws CoreException {
            return null;
        }

        @Override
        public void addValueToMessage(AdaptrisMessage msg, Object value) throws CoreException {
        }

        @Override
        public String getKeyFromMessage(AdaptrisMessage msg) throws CoreException {
            return null;
        }
    }
}