Coverage Report - org.mule.module.json.JsonExpressionEvaluator
 
Classes in this File Line Coverage Branch Coverage Complexity
JsonExpressionEvaluator
0%
0/53
0%
0/52
0
 
 1  
 /*
 2  
  * $Id: JsonExpressionEvaluator.java 20383 2010-11-29 19:44:13Z dfeist $
 3  
  * --------------------------------------------------------------------------------------
 4  
  * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 5  
  *
 6  
  * The software in this package is published under the terms of the CPAL v1.0
 7  
  * license, a copy of which has been included with this distribution in the
 8  
  * LICENSE.txt file.
 9  
  */
 10  
 
 11  
 package org.mule.module.json;
 12  
 
 13  
 import org.mule.api.MuleMessage;
 14  
 import org.mule.api.MuleRuntimeException;
 15  
 import org.mule.api.expression.ExpressionEvaluator;
 16  
 import org.mule.config.i18n.CoreMessages;
 17  
 import org.mule.util.NumberUtils;
 18  
 
 19  
 import java.util.ArrayList;
 20  
 import java.util.Iterator;
 21  
 import java.util.List;
 22  
 
 23  
 import org.apache.commons.logging.Log;
 24  
 import org.apache.commons.logging.LogFactory;
 25  
 import org.codehaus.jackson.JsonNode;
 26  
 import org.codehaus.jackson.node.ArrayNode;
 27  
 import org.codehaus.jackson.node.ObjectNode;
 28  
 import org.codehaus.jackson.node.ValueNode;
 29  
 
 30  
 /**
 31  
  * An expression evaluator to allow users to define json expressions in their mule configuration, i.e.
 32  
  * <code>
 33  
  * #[json:person/addresses[0]/postcode]
 34  
  * </code>
 35  
  * <p/>
 36  
  * See the {@link org.mule.module.json.JsonData} object for mor information about the query syntax.
 37  
  * <p/>
 38  
  * It is also possible to use this evaluator in {@link org.mule.routing.filters.ExpressionFilter} objects. For example
 39  
  * a filter could be defined as -
 40  
  * <p/>
 41  
  * <code>
 42  
  * #[json:person/registered]
 43  
  * </code>
 44  
  * <p/>
 45  
  * Where 'registered' is a boolean value.  It is also possible to filter on the existence of a value i.e.
 46  
  * <p/>
 47  
  * <code>
 48  
  * #[json:person/favouriteColour]
 49  
  * </code>
 50  
  * <p/>
 51  
  * Which would return true if 'favouriteColour' has been set. This evaluator also dds two logic operators you can use
 52  
  * to create more sophisticated boolean expressions; equals and not equals -
 53  
  * <p/>
 54  
  * <code>
 55  
  * #[json:person/favouriteColour = red]
 56  
  * </code>
 57  
  * <p/>
 58  
  * or
 59  
  * <p/>
 60  
  * <code>
 61  
  * #[json:person/favouriteColour != brown]
 62  
  * </code>
 63  
  *
 64  
  * @see org.mule.module.json.JsonData
 65  
  */
 66  0
 public class JsonExpressionEvaluator implements ExpressionEvaluator
 67  
 {
 68  
     /**
 69  
      * logger used by this class
 70  
      */
 71  0
     protected transient final Log logger = LogFactory.getLog(JsonExpressionEvaluator.class);
 72  
 
 73  
     public Object evaluate(String expression, MuleMessage message)
 74  
     {
 75  0
         String compareTo = null;
 76  0
         boolean not = false;
 77  0
         int start = expression.lastIndexOf("/");
 78  0
         if (start == -1)
 79  
         {
 80  0
             start = 0;
 81  
         }
 82  0
         int i=0;
 83  0
         if ((i = expression.indexOf("!=", start)) > -1)
 84  
         {
 85  0
             compareTo = expression.substring(i + 2, expression.length()).trim();
 86  0
             expression = expression.substring(0, i).trim();
 87  0
             not = true;
 88  
         }
 89  0
         else if ((i = expression.indexOf("=", start)) > -1)
 90  
         {
 91  0
             compareTo = expression.substring(i + 1, expression.length()).trim();
 92  0
             expression = expression.substring(0, i).trim();
 93  
         }
 94  
         
 95  
         try
 96  
         {
 97  0
             String json = message.getPayloadAsString();
 98  0
             JsonData data = new JsonData(json);
 99  
             try
 100  
             {
 101  0
                 JsonNode resultNode = data.get(expression);
 102  0
                 if (compareTo != null)
 103  
                 {
 104  0
                     Object resultValue = resultNode.isValueNode() ? resultNode.getValueAsText() : resultNode;
 105  0
                     if (compareTo.equalsIgnoreCase("null"))
 106  
                     {
 107  0
                         boolean answer = resultValue == null;
 108  0
                         return (not ? !answer : answer);
 109  
                     }
 110  0
                     else if (resultValue instanceof Number && NumberUtils.isDigits(compareTo))
 111  
                     {
 112  0
                         boolean answer = NumberUtils.createNumber(compareTo).equals(resultValue);
 113  0
                         return (not ? !answer : answer);
 114  
                     }
 115  0
                     else if (resultValue instanceof Boolean
 116  
                              && (compareTo.equalsIgnoreCase("true") || compareTo.equalsIgnoreCase("false")))
 117  
                     {
 118  0
                         boolean answer = resultValue.equals(Boolean.valueOf(compareTo));
 119  0
                         return (not ? !answer : answer);
 120  
                     }
 121  
                     else
 122  
                     {
 123  0
                         boolean answer = compareTo.equals(resultValue);
 124  0
                         return (not ? !answer : answer);
 125  
                     }
 126  
                 }
 127  
                 else
 128  
                 {
 129  0
                     return extractResultFromNode(resultNode);
 130  
                 }
 131  
             }
 132  0
             catch (IllegalArgumentException e)
 133  
             {
 134  0
                 if (compareTo == null)
 135  
                 {
 136  0
                     logger.debug("returning null for json expression: " + expression + ": " + e.getMessage());
 137  0
                     return null;
 138  
                 }
 139  
                 //If the element does not exist but is matching against 'null' return true, otherwise false
 140  0
                 return (compareTo.equalsIgnoreCase("null")) & !not;
 141  
             }
 142  
         }
 143  0
         catch (Exception e)
 144  
         {
 145  0
             throw new MuleRuntimeException(CoreMessages.failedToProcessExtractorFunction(getName() + ":" + expression), e);
 146  
         }
 147  
     }
 148  
 
 149  
     protected Object extractResultFromNode(JsonNode result)
 150  
     {
 151  0
         if (result instanceof ValueNode)
 152  
         {
 153  0
             return result.getValueAsText();
 154  
         }
 155  0
         if (result instanceof ObjectNode)
 156  
         {
 157  0
             return ((ObjectNode) result).toString();
 158  
         }
 159  0
         else if (result instanceof ArrayNode)
 160  
         {
 161  0
             List parts = new ArrayList();
 162  0
             for (Iterator<JsonNode> i = ((JsonNode) result).getElements(); i.hasNext();)
 163  
             {
 164  0
                 JsonNode arrayNode = i.next();
 165  0
                 parts.add(extractResultFromNode(arrayNode));
 166  0
             }
 167  0
             return parts;
 168  
         }
 169  
         else
 170  
         {
 171  0
             return result;
 172  
         }
 173  
     }
 174  
     
 175  
     public void setName(String name)
 176  
     {
 177  0
         throw new UnsupportedOperationException("setName");
 178  
     }
 179  
 
 180  
     public String getName()
 181  
     {
 182  0
         return "json";
 183  
     }
 184  
 }