Java tutorial
/** * Copyright 2010-2013 Nokia * * 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.googlecode.jsonschema2pojo.rules; import static org.apache.commons.lang.StringUtils.*; import java.text.ParseException; import java.util.ArrayList; import java.util.Arrays; import java.util.Date; import java.util.HashSet; import java.util.List; import java.util.Set; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.util.StdDateFormat; import com.googlecode.jsonschema2pojo.Schema; import com.sun.codemodel.ClassType; import com.sun.codemodel.JClass; import com.sun.codemodel.JDefinedClass; import com.sun.codemodel.JExpr; import com.sun.codemodel.JExpression; import com.sun.codemodel.JFieldVar; import com.sun.codemodel.JInvocation; import com.sun.codemodel.JType; /** * Applies the "enum" schema rule. * * @see <a * href="http://tools.ietf.org/html/draft-zyp-json-schema-03#section-5.20">http://tools.ietf.org/html/draft-zyp-json-schema-03#section-5.20</a> */ public class DefaultRule implements Rule<JFieldVar, JFieldVar> { /** * Applies this schema rule to take the required code generation steps. * <p> * Default values are implemented by assigning an expression to the given * field (so when instances of the generated POJO are created, its fields * will then contain their default values). * <p> * Collections (Lists and Sets) are initialized to an empty collection, even * when no default value is present in the schema (node is null). * * @param nodeName * the name of the property which has (or may have) a default * @param node * the default node (may be null if no default node was present * for this property) * @param field * the Java field that has added to a generated type to represent * this property * @return field, which will have an init expression is appropriate */ @Override public JFieldVar apply(String nodeName, JsonNode node, JFieldVar field, Schema currentSchema) { boolean defaultPresent = node != null && isNotEmpty(node.asText()); String fieldType = field.type().fullName(); if (fieldType.startsWith(List.class.getName())) { field.init(getDefaultList(field.type(), node)); } else if (fieldType.startsWith(Set.class.getName())) { field.init(getDefaultSet(field.type(), node)); } else if (defaultPresent) { field.init(getDefaultValue(field.type(), node)); } return field; } private JExpression getDefaultValue(JType fieldType, JsonNode node) { if (!fieldType.isPrimitive() && node.isNull()) { return JExpr._null(); } fieldType = fieldType.unboxify(); if (fieldType.fullName().equals(String.class.getName())) { return JExpr.lit(node.asText()); } else if (fieldType.fullName().equals(int.class.getName())) { return JExpr.lit(Integer.parseInt(node.asText())); } else if (fieldType.fullName().equals(double.class.getName())) { return JExpr.lit(Double.parseDouble(node.asText())); } else if (fieldType.fullName().equals(boolean.class.getName())) { return JExpr.lit(Boolean.parseBoolean(node.asText())); } else if (fieldType.fullName().equals(Date.class.getName())) { long millisecs = parseDateToMillisecs(node.asText()); JInvocation newDate = JExpr._new(fieldType.owner().ref(Date.class)); newDate.arg(JExpr.lit(millisecs)); return newDate; } else if (fieldType.fullName().equals(long.class.getName())) { return JExpr.lit(Long.parseLong(node.asText())); } else if (fieldType instanceof JDefinedClass && ((JDefinedClass) fieldType).getClassType().equals(ClassType.ENUM)) { return getDefaultEnum(fieldType, node); } else { return JExpr._null(); } } /** * Creates a default value for a list property by: * <ol> * <li>Creating a new {@link ArrayList} with the correct generic type * <li>Using {@link Arrays#asList(Object...)} to initialize the list with * the correct default values * </ol> * * @param fieldType * the java type that applies for this field ({@link List} with * some generic type argument) * @param node * the node containing default values for this list * @return an expression that creates a default value that can be assigned * to this field */ private JExpression getDefaultList(JType fieldType, JsonNode node) { JClass listGenericType = ((JClass) fieldType).getTypeParameters().get(0); JClass listImplClass = fieldType.owner().ref(ArrayList.class); listImplClass = listImplClass.narrow(listGenericType); JInvocation newListImpl = JExpr._new(listImplClass); if (node instanceof ArrayNode && node.size() > 0) { JInvocation invokeAsList = fieldType.owner().ref(Arrays.class).staticInvoke("asList"); for (JsonNode defaultValue : node) { invokeAsList.arg(getDefaultValue(listGenericType, defaultValue)); } newListImpl.arg(invokeAsList); } return newListImpl; } /** * Creates a default value for a set property by: * <ol> * <li>Creating a new {@link HashSet} with the correct generic type * <li>Using {@link Arrays#asList(Object...)} to initialize the set with the * correct default values * </ol> * * @param fieldType * the java type that applies for this field ({@link Set} with * some generic type argument) * @param node * the node containing default values for this set * @return an expression that creates a default value that can be assigned * to this field */ private JExpression getDefaultSet(JType fieldType, JsonNode node) { JClass setGenericType = ((JClass) fieldType).getTypeParameters().get(0); JClass setImplClass = fieldType.owner().ref(HashSet.class); setImplClass = setImplClass.narrow(setGenericType); JInvocation newSetImpl = JExpr._new(setImplClass); if (node instanceof ArrayNode) { JInvocation invokeAsList = fieldType.owner().ref(Arrays.class).staticInvoke("asList"); for (JsonNode defaultValue : node) { invokeAsList.arg(getDefaultValue(setGenericType, defaultValue)); } newSetImpl.arg(invokeAsList); } return newSetImpl; } private JExpression getDefaultEnum(JType fieldType, JsonNode node) { JInvocation invokeFromValue = ((JClass) fieldType).staticInvoke("fromValue"); invokeFromValue.arg(node.asText()); return invokeFromValue; } private long parseDateToMillisecs(String valueAsText) { try { return Long.parseLong(valueAsText); } catch (NumberFormatException nfe) { try { return new StdDateFormat().parse(valueAsText).getTime(); } catch (ParseException pe) { throw new IllegalArgumentException("Unable to parse this string as a date: " + valueAsText); } } } }