Revision 45633 trunk/org.gvsig.desktop/org.gvsig.desktop.library/org.gvsig.expressionevaluator/org.gvsig.expressionevaluator.lib/org.gvsig.expressionevaluator.lib.impl/src/main/java/org/gvsig/expressionevaluator/impl/function/typeconversion/JsonValueFunction.java

View differences:

JsonValueFunction.java
22 22 
 */
23 23 
public class JsonValueFunction extends AbstractFunction {
24 24
25 
    //JsonPathContextImpl implements JsonPathContext {
26 
    // https://github.com/json-path/JsonPath
25 
        //
26 
        // function docs at:
27 
        // Oracle json_value: https://docs.oracle.com/database/121/SQLRF/functions093.htm#SQLRF56668
28 
        // SQLServer json_value: https://docs.microsoft.com/es-es/sql/t-sql/functions/json-value-transact-sql?view=sql-server-ver15
29 
        // PostgreSQL jsonb_path_query: https://www.postgresql.org/docs/12/functions-json.html#FUNCTIONS-JSON-PROCESSING-TABLE
30 
        // The implementation used is:
31 
        // https://github.com/json-path/JsonPath
32 
        //
33
27 34 
    public JsonValueFunction() {
28 35 
        super(GROUP_CONVERSION, FUNCTION_JSON_VALUE, Range.is(2),
29 
                "Get value from a Json with a specific path.",
30 
            FUNCTION_JSON_VALUE+"({{json}}, '[jsonpath]')");
31 
        this.addAlias("JSON_VALUE");
36 
                "finds a specified scalar JSON value in JSON data and returns it.",
37 
            FUNCTION_JSON_VALUE+"({{expr}}, JsonPath)",
38 
            new String[]{
39 
                "expr - specify an expression that evaluates to a text literal.",
40 
                "JsonPath - specify a JSON path expression."
41 
            }
42 
        );
32 43 
    }
33 44 

  		




  34
  45
  
    
    @Override


  		




  ......




  38
  49
  
    

  		




  39
  50
  
    
    public static Object json_value(String json, String path) {


  		




  40
  51
  
    
        JsonManager manager = ToolsUtilLocator.getJsonManager();


  		




  41
  
  
    
        JsonPathContext context = manager.createJSonPathContext(json);


  		




  
  52
  
    
        JsonPathContext context;


  		




  
  53
  
    
        try {


  		




  
  54
  
    
            context = manager.createJSonPathContext(json);


  		




  
  55
  
    
        } catch(Exception ex) {


  		




  
  56
  
    
            return null;


  		




  
  57
  
    
        }


  		




  42
  58
  
    
        Object value = context.get(path);


  		




  43
  59
  
    
        if( value instanceof List ) {


  		




  44
  60
  
    
            List l = ((List)value);


  		




  ......




  56
  72
  
    
        String path = this.getStr(args, 1);


  		




  57
  73
  
    
        Object value = json_value(json, path);


  		




  58
  74
  
    
        


  		




  59
  
  
    
        return value;   }


  		




  
  75
  
    
        return value;  


  		




  
  76
  
    
    }


  		




  60
  77
  
    

  		




  61
  78
  
    
}


  		












Also available in:  Unified diff