Java tutorial
/** * Copyright 2012 Lyncode * * Licensed 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 com.lyncode.jtwig.functions.internal.list; import com.lyncode.jtwig.functions.Function; import com.lyncode.jtwig.functions.exceptions.FunctionException; import org.apache.commons.lang3.StringUtils; public class Join implements Function { @Override public Object execute(Object... arguments) throws FunctionException { if (arguments.length < 1) throw new FunctionException("Requires at least a list as argument"); String separator = ""; if (arguments.length == 2) separator = arguments[1].toString(); if (arguments[0] == null) return ""; else if (arguments[0] instanceof Iterable) return StringUtils.join((Iterable) arguments[0], separator); else if (arguments[0].getClass().isArray()) return StringUtils.join((Object[]) arguments[0], separator); else throw new FunctionException("First arguments must be a list or an array."); } }