How to use

load

method

in

org.apache.metron.stellar.common.utils.JSONUtils

/**
 * Fetches the global configuration from Zookeeper.
 * @param zkClient The Zookeeper client.
 * @return The global configuration retrieved from Zookeeper.
 * @throws Exception
 */
private Map<String, Object> fetchGlobalConfig(CuratorFramework zkClient) throws Exception {
 byte[] raw = readGlobalConfigBytesFromZookeeper(zkClient);
 return JSONUtils.INSTANCE.load( new ByteArrayInputStream(raw), JSONUtils.MAP_SUPPLIER);
}

/**
 * Loads any variables defined in an external file.
 * @param commandLine The command line arguments.
 * @param executor The stellar executor.
 * @throws IOException
 */
private static void loadVariables(
    CommandLine commandLine,
    StellarShellExecutor executor) throws IOException {
 if(commandLine.hasOption("v")) {
  // load variables defined in a file
  String variablePath = commandLine.getOptionValue("v");
  Map<String, Object> variables = JSONUtils.INSTANCE.load(
      new File(variablePath),
      JSONUtils.MAP_SUPPLIER);
  // for each variable...
  for(Map.Entry<String, Object> kv : variables.entrySet()) {
   String variable = kv.getKey();
   Object value = kv.getValue();
   // define the variable - no expression available
   executor.assign(variable, value, Optional.empty());
  }
 }
}

 @Override
 public Object apply(List<Object> strings) {
  if (strings == null || strings.size() == 0) {
   throw new IllegalArgumentException("[TO_JSON_OBJECT] incorrect arguments. Usage: TO_JSON_OBJECT <String>");
  }
  String var = (strings.get(0) == null) ? null : (String) strings.get(0);
  if (var == null) {
   return null;
  } else if (var.length() == 0) {
   return var;
  } else {
   if (!(strings.get(0) instanceof String)) {
    throw new ParseException("Valid JSON string not supplied");
   }
   // Return JSON Object
   try {
    return JSONUtils.INSTANCE.load((String) strings.get(0), Object.class);
   } catch (JsonProcessingException ex) {
    throw new ParseException("Valid JSON string not supplied", ex);
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
  return new ParseException("Unable to parse JSON string");
 }
}

/**
 * Executes a given expression on a message.
 *
 * @param expr The filter expression to execute.
 * @param message The message that the expression is executed on.
 * @return Returns true, only if the expression returns true.  If the expression
 * returns false or fails to execute, false is returned.
 */
public boolean isSatisfied(LambdaExpression expr, String message) {
 boolean result = false;
 Map<String, Object> messageAsMap;
 try {
  // transform the message to a map of fields
  messageAsMap = JSONUtils.INSTANCE.load(message, JSONUtils.MAP_SUPPLIER);
  // apply the filter expression
  Object out = expr.apply(Collections.singletonList(messageAsMap));
  if(out instanceof Boolean) {
   result = (Boolean) out;
  } else {
   LOG.error("Expected boolean from filter expression, got {}", ClassUtils.getShortClassName(out, "null"));
  }
 } catch(IOException e) {
  LOG.error("Unable to parse message", e);
 }
 return result;
}

 @Override
 public Object apply(List<Object> strings) {
  if (strings == null || strings.size() == 0) {
   throw new IllegalArgumentException("[TO_JSON_MAP] incorrect arguments. Usage: TO_JSON_MAP <JSON String>");
  }
  String var = (strings.get(0) == null) ? null : (String) strings.get(0);
  if (var == null) {
   return null;
  } else if (var.length() == 0) {
   return var;
  } else {
   if (!(strings.get(0) instanceof String)) {
    throw new ParseException("Valid JSON string not supplied");
   }
   // Return parsed JSON Object as a HashMap
   String in = (String)strings.get(0);
   try {
    return (Map)JSONUtils.INSTANCE.load(in, JSONUtils.MAP_SUPPLIER);
   } catch (JsonProcessingException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string", in), ex);
   } catch (IOException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string", in), ex);
   }
   catch (ClassCastException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string, expected a map", in), ex);
   }
  }
 }
}

 @Override
 public Object apply(List<Object> strings) {
  if (strings == null || strings.size() == 0) {
   throw new IllegalArgumentException("[TO_JSON_LIST] incorrect arguments. Usage: TO_JSON_LIST <JSON String>");
  }
  String var = (strings.get(0) == null) ? null : (String) strings.get(0);
  if (var == null) {
   return null;
  } else if (var.length() == 0) {
   return var;
  } else {
   if (!(strings.get(0) instanceof String)) {
    throw new ParseException("Valid JSON string not supplied");
   }
   // Return parsed JSON Object as a List
   String in = (String)strings.get(0);
   try {
    return (List) JSONUtils.INSTANCE.load(in, JSONUtils.LIST_SUPPLIER);
   } catch (JsonProcessingException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string", in), ex);
   } catch (IOException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string", in), ex);
   }
   catch (ClassCastException ex) {
    throw new ParseException(String.format("%s is not a valid JSON string, expected a list", in), ex);
   }
  }
 }
}

ret = JSONUtils.INSTANCE.load(results, JSONUtils.MAP_SUPPLIER);
resultCache.put(cacheKey, ret);
return ret;

return JSONUtils.INSTANCE.load(json, JSONUtils.MAP_SUPPLIER);

Map<String, Object> variables = new HashMap<>();
if (variablesFile.isPresent()) {
 variables = JSONUtils.INSTANCE.load(new FileInputStream(variablesFile.get()), JSONUtils.MAP_SUPPLIER);

@Test
@SuppressWarnings("unchecked")
public void loads_file_with_map_class() throws Exception {
 Map<String, Object> expected = new HashMap<String, Object>() {{
  put("a", "hello");
  put("b", "world");
 }};
 Map<String, Object> actual = JSONUtils.INSTANCE.load(configFile, Map.class);
 Assert.assertThat("config not equal", actual, equalTo(expected));
}

@Test
public void loads_file_with_typeref() throws Exception {
 Map<String, Object> expected = new HashMap<String, Object>() {{
  put("a", "hello");
  put("b", "world");
 }};
 Map<String, Object> actual = JSONUtils.INSTANCE.load(configFile, JSONUtils.MAP_SUPPLIER);
 Assert.assertThat("config not equal", actual, equalTo(expected));
}

@Test
public void loads_file_with_custom_class() throws Exception {
 TestConfig expected = new TestConfig().setA("hello").setB("world");
 TestConfig actual = JSONUtils.INSTANCE.load(configFile, TestConfig.class);
 Assert.assertThat("a not equal", actual.getA(), equalTo(expected.getA()));
 Assert.assertThat("b not equal", actual.getB(), equalTo(expected.getB()));
}