org.jmingo.mapping.marshall.mongo.callback.EscapeEmptyCallback.java Source code

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Here is the source code for org.jmingo.mapping.marshall.mongo.callback.EscapeEmptyCallback.java

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/**
 * Copyright 2013-2014 The JMingo Team
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 org.jmingo.mapping.marshall.mongo.callback;

import com.mongodb.BasicDBObject;
import com.mongodb.util.JSONCallback;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;

/*
Entries with empty values will be removed from pipeline.
- * Example:
- * source: {$match : { "field1": { $in: []}, "field2": { "$gt" : "value2"}}}
- * after build:[{$match : {field2": { "$gt" : "value2"}}}]
- * <p/>
- * source: {$match : { "field1": { $in: [value1, value2]}, "field2": { "$gt" : ""}}}
- * after build:[ {$match : { "field1": { $in: [value1, value2]}}} ]
*/
public class EscapeEmptyCallback extends JSONCallback {

    @Override
    public void gotString(String name, String v) {
        // exclude fields with empty parameters
        if (StringUtils.isNotEmpty(v)) {
            super.gotString(name, v);
        }
    }

    @Override
    protected void _put(String name, Object val) {
        if (isElementNotEmpty(val)) {
            super._put(name, val);
        }
    }

    @Override
    public Object objectDone() {
        String name = curName();
        Object done = super.objectDone();

        if (name != null && !isElementNotEmpty(done)) {
            return cur().removeField(name);
        }
        return done;
    }

    private boolean isElementNotEmpty(Object value) {
        if (value instanceof BasicDBObject) {
            BasicDBObject dbObjVal = (BasicDBObject) value;
            if (dbObjVal.isEmpty()) {
                return false;
            }
            for (Map.Entry<String, Object> entry : dbObjVal.entrySet()) {
                boolean tmp = isElementNotEmpty(entry.getValue());
                if (!tmp) {
                    return false;
                }
            }
        }
        return true;
    }

}