package org.springframework.batch.item.file.mapping;
   
   import java.util.Map;
   
   import org.codehaus.jackson.JsonParser;
   import org.codehaus.jackson.map.MappingJsonFactory;
   import org.springframework.batch.item.file.LineMapper;
   
   /**
   * Interpret a line as a Json object and parse it up to a Map. The line should be a standard Json object, starting with
   * "{" and ending with "}" and composed of <code>name:value</code> pairs separated by commas. Whitespace is ignored,
   * e.g.
   * 
   * <pre>
   * { "foo" : "bar", "value" : 123 }
   * </pre>
   * 
   * The values can also be Json objects (which are converted to maps):
   * 
   * <pre>
   * { "foo": "bar", "map": { "one": 1, "two": 2}}
   * </pre>
   * 
   * @author Dave Syer
   * 
   */
  public class JsonLineMapper implements LineMapper<Map<String, Object>> {
  
  	private MappingJsonFactory factory = new MappingJsonFactory();
  
  	/**
  	 * Interpret the line as a Json object and create a Map from it.
  	 * 
  	 * @see LineMapper#mapLine(String, int)
  	 */
      @Override
  	public Map<String, Object> mapLine(String line, int lineNumber) throws Exception {
  		Map<String, Object> result;
  		JsonParser parser = factory.createJsonParser(line);
  		@SuppressWarnings("unchecked")
  		Map<String, Object> token = parser.readValueAs(Map.class);
  		result = token;
  		return result;
  	}
  
  }