/*
* $Id: JsonData.java 21827 2011-05-06 17:35:25Z dandiep $
* --------------------------------------------------------------------------------------
* Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com
*
* The software in this package is published under the terms of the CPAL v1.0
* license, a copy of which has been included with this distribution in the
* LICENSE.txt file.
*/
package org.mule.module.json;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.Serializable;
import java.io.StringReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
/**
* A wrapper for the {@link org.codehaus.jackson.JsonNode} object that
* allows for nested object keys i.e. user/name will return the name property on
* the user object.
* <p/>
* There is no 'xpath' for JSON yet (though I expect Jackson to do implement this at some point).
* This class provides a simple way to navigate a Json data structure. To select a child entry use -
* <code>
* person/name
* </code>
* <p/>
* to access array data, use square braces with an index value i.e.
* <code>
* person/addresses[0]/postcode
* <p/>
* or
* <p/>
* [0]/arrayElement
* </code>
* <p/>
* Also, multi-dimensional arrays can be accessed using:
* <code>
* filters[1]/init[1][0]
* </code>
* <p/>
* if a Json property name contains a '/' the name needs to be quoted with single quotes i.e.
* <p/>
* <code>
* results/'http://foo.com'/value
* </code>
*/
public class JsonData implements Serializable
{
private JsonNode node;
public JsonData(JsonNode node)
{
this.node = node;
}
public JsonData(URL node) throws IOException
{
this(node.openStream());
}
public JsonData(InputStream node) throws IOException
{
this.node = new ObjectMapper().readTree(node);
}
public JsonData(Reader node) throws IOException
{
this.node = new ObjectMapper().readTree(node);
}
public JsonData(String node) throws IOException
{
this(new StringReader(node));
}
public JsonNode get(int index)
{
return node.get(index);
}
public boolean isArray()
{
return node.isArray();
}
public JsonNode[] toArray()
{
List<JsonNode> children = new ArrayList<JsonNode>();
for (Iterator<JsonNode> itr = node.getElements(); itr.hasNext();)
{
children.add(itr.next());
}
return children.toArray(new JsonNode[children.size()]);
}
public JsonNode get(String expression)
{
List<String> tokens = parseTokens(expression);
JsonNode o = node;
for (String token : tokens)
{
if (token.startsWith("["))
{
if (o.isArray())
{
int index = Integer.valueOf(token.substring(1, token.length() - 1));
o = o.path(index);
}
else
{
throw new IllegalArgumentException("Current node is not an array, but expression is expecting one");
}
}
else
{
o = o.path(token);
}
if (o.isMissingNode())
{
throw new IllegalArgumentException("Not a valid element: " + token);
}
}
return o;
}
public String getAsString(String expression)
{
JsonNode node = get(expression);
if (node.isValueNode())
{
return node.getValueAsText();
}
else
{
return node.toString();
}
}
public boolean hasNode(String key)
{
JsonNode result = node.path(key);
return result.isMissingNode() == false;
}
protected List<String> parseTokens(String expresion)
{
List<String> tokens = new ArrayList<String>();
while (expresion.length() > 0)
{
int slash = expresion.indexOf("/");
int brace = expresion.indexOf("[");
//Handled quoted strings
if (expresion.charAt(0) == '\'')
{
if (expresion.endsWith("'"))
{
tokens.add(expresion.substring(1, expresion.length() - 1));
expresion = "";
}
else
{
int x = expresion.indexOf("'/");
tokens.add(expresion.substring(1, x));
expresion = expresion.substring(x + 2);
}
}
else if (slash == -1 && brace == -1)
{
tokens.add(expresion);
expresion = "";
}
else if ((slash > -1 && slash < brace) || brace == -1)
{
if (slash == 0)
{
if (expresion.charAt(1) == '\'')
{
int x = expresion.indexOf("'", 2);
tokens.add(expresion.substring(2, x));
expresion = expresion.substring(x + 1);
}
else if (expresion.charAt(1) == '[')
{
int i = expresion.indexOf("]", 1);
tokens.add(expresion.substring(0, i));
expresion = expresion.substring(i + 1);
}
else
{
expresion = expresion.substring(slash + 1);
}
}
else
{
tokens.add(expresion.substring(0, slash));
expresion = expresion.substring(slash + 1);
}
}
else if (brace > 0)
{
tokens.add(expresion.substring(0, brace));
expresion = expresion.substring(brace);
}
else
{
int i = expresion.indexOf("]", brace);
tokens.add(expresion.substring(0, i + 1));
expresion = expresion.substring(i + 1);
}
}
return tokens;
}
@Override
public boolean equals(Object obj)
{
return node.equals(obj);
}
@Override
public int hashCode()
{
return node.hashCode();
}
@Override
public String toString()
{
return node.toString();
}
}