GetArrayFunctionExtension.java
/*
* Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. licenses this file to you under the Apache License,
* Version 2.0 (the "License"); you may not use this file except
* in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.wso2.extension.siddhi.execution.json;
import org.json.JSONArray;
import org.wso2.siddhi.core.config.ExecutionPlanContext;
import org.wso2.siddhi.core.executor.ExpressionExecutor;
import org.wso2.siddhi.core.executor.function.FunctionExecutor;
import org.wso2.siddhi.query.api.definition.Attribute;
import org.wso2.siddhi.query.api.exception.ExecutionPlanValidationException;
/**
* getArray(elements..)
* Returns json array of elements as a string
* Accept Type(s): (STRING|INT|DOUBLE|FLOAT|OBJECT ..)
* Return Type(s): (STRING)
*/
public class GetArrayFunctionExtension extends FunctionExecutor {
private Attribute.Type returnType = Attribute.Type.STRING;
@Override
protected void init(ExpressionExecutor[] attributeExpressionExecutors,
ExecutionPlanContext executionPlanContext) {
if (attributeExpressionExecutors.length <= 0) {
throw new ExecutionPlanValidationException(
"Invalid no of arguments passed to json:getArray() function," + " required one or more, but found "
+ attributeExpressionExecutors.length);
}
Attribute.Type inputType = attributeExpressionExecutors[0].getReturnType();
for (int i = 1; i < attributeExpressionExecutors.length; i++) {
if (attributeExpressionExecutors[0].getReturnType() != inputType) {
throw new ExecutionPlanValidationException(
"Parameter types are inconsistent. All parameters should be same");
}
}
}
@Override
protected Object execute(Object[] data) {
JSONArray jsonArray = new JSONArray();
for (Object obj : data) {
jsonArray.put(obj);
}
return jsonArray.toString();
}
@Override
protected Object execute(Object data) {
return execute(new Object[]{data});
}
@Override
public void start() {
//Nothing to start
}
@Override
public void stop() {
//Nothing to stop
}
@Override
public Attribute.Type getReturnType() {
return returnType;
}
@Override
public Object[] currentState() {
return null; //No need to maintain a state.
}
@Override
public void restoreState(Object[] state) {
//Since there's no need to maintain a state, nothing needs to be done here.
}
}