org.jsonschema2pojo.rules.EnumRule Maven / Gradle / Ivy
/**
* Copyright © 2010-2017 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 org.jsonschema2pojo.rules;
import static java.util.Arrays.*;
import static org.apache.commons.lang3.StringUtils.*;
import static org.jsonschema2pojo.rules.PrimitiveTypes.*;
import static org.jsonschema2pojo.util.TypeUtil.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.jsonschema2pojo.Schema;
import org.jsonschema2pojo.exception.ClassAlreadyExistsException;
import org.jsonschema2pojo.exception.GenerationException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.sun.codemodel.ClassType;
import com.sun.codemodel.JBlock;
import com.sun.codemodel.JClass;
import com.sun.codemodel.JClassAlreadyExistsException;
import com.sun.codemodel.JClassContainer;
import com.sun.codemodel.JConditional;
import com.sun.codemodel.JDefinedClass;
import com.sun.codemodel.JEnumConstant;
import com.sun.codemodel.JExpr;
import com.sun.codemodel.JExpression;
import com.sun.codemodel.JFieldVar;
import com.sun.codemodel.JForEach;
import com.sun.codemodel.JInvocation;
import com.sun.codemodel.JMethod;
import com.sun.codemodel.JMod;
import com.sun.codemodel.JType;
import com.sun.codemodel.JVar;
/**
* Applies the "enum" schema rule.
*
* @see http:
* //tools.ietf.org/html/draft-zyp-json-schema-03#section-5.19
*/
public class EnumRule implements Rule {
private static final String VALUE_FIELD_NAME = "value";
private final RuleFactory ruleFactory;
protected EnumRule(RuleFactory ruleFactory) {
this.ruleFactory = ruleFactory;
}
/**
* Applies this schema rule to take the required code generation steps.
*
* A Java {@link Enum} is created, with constants for each of the enum
* values present in the schema. The enum name is derived from the nodeName,
* and the enum type itself is created as an inner class of the owning type.
* In the rare case that no owning type exists (the enum is the root of the
* schema), then the enum becomes a public class in its own right.
*
* The actual JSON value for each enum constant is held in a property called
* "value" in the generated type. A static factory method
* fromValue(String) is added to the generated enum, and the
* methods are annotated to allow Jackson to marshal/unmarshal values
* correctly.
*
* @param nodeName
* the name of the property which is an "enum"
* @param node
* the enum node
* @param container
* the class container (class or package) to which this enum
* should be added
* @return the newly generated Java type that was created to represent the
* given enum
*/
@Override
public JType apply(String nodeName, JsonNode node, JClassContainer container, Schema schema) {
JDefinedClass _enum;
try {
_enum = createEnum(node, nodeName, container);
} catch (ClassAlreadyExistsException e) {
return e.getExistingClass();
}
schema.setJavaTypeIfEmpty(_enum);
if (node.has("javaInterfaces")) {
addInterfaces(_enum, node.get("javaInterfaces"));
}
// copy our node; remove the javaType as it will throw off the TypeRule for our case
ObjectNode typeNode = (ObjectNode)node.deepCopy();
typeNode.remove("javaType");
// If type is specified on the enum, get a type rule for it. Otherwise, we're a string.
// (This is different from the default of Object, which is why we don't do this for every case.)
JType backingType = node.has("type") ?
ruleFactory.getTypeRule().apply(nodeName, typeNode, container, schema) :
container.owner().ref(String.class);
JFieldVar valueField = addValueField(_enum, backingType);
// override toString only if we have a sensible string to return
if(isString(backingType)){
addToString(_enum, valueField);
}
addValueMethod(_enum, valueField);
addEnumConstants(node.path("enum"), _enum, node.path("javaEnumNames"), backingType);
addFactoryMethod(_enum, backingType);
return _enum;
}
private JDefinedClass createEnum(JsonNode node, String nodeName, JClassContainer container) throws ClassAlreadyExistsException {
try {
if (node.has("javaType")) {
String fqn = node.get("javaType").asText();
if (isPrimitive(fqn, container.owner())) {
throw new GenerationException("Primitive type '" + fqn + "' cannot be used as an enum.");
}
try {
Class existingClass = Thread.currentThread().getContextClassLoader().loadClass(fqn);
throw new ClassAlreadyExistsException(container.owner().ref(existingClass));
} catch (ClassNotFoundException e) {
return container.owner()._class(fqn, ClassType.ENUM);
}
} else {
try {
return container._class(JMod.PUBLIC, getEnumName(nodeName, node, container), ClassType.ENUM);
} catch (JClassAlreadyExistsException e) {
throw new GenerationException(e);
}
}
} catch (JClassAlreadyExistsException e) {
throw new ClassAlreadyExistsException(e.getExistingClass());
}
}
private void addFactoryMethod(JDefinedClass _enum, JType backingType) {
JFieldVar quickLookupMap = addQuickLookupMap(_enum, backingType);
JMethod fromValue = _enum.method(JMod.PUBLIC | JMod.STATIC, _enum, "fromValue");
JVar valueParam = fromValue.param(backingType, "value");
JBlock body = fromValue.body();
JVar constant = body.decl(_enum, "constant");
constant.init(quickLookupMap.invoke("get").arg(valueParam));
JConditional _if = body._if(constant.eq(JExpr._null()));
JInvocation illegalArgumentException = JExpr._new(_enum.owner().ref(IllegalArgumentException.class));
JExpression expr = valueParam;
// if string no need to add ""
if(!isString(backingType)){
expr = expr.plus(JExpr.lit(""));
}
illegalArgumentException.arg(expr);
_if._then()._throw(illegalArgumentException);
_if._else()._return(constant);
ruleFactory.getAnnotator().enumCreatorMethod(fromValue);
}
private JFieldVar addQuickLookupMap(JDefinedClass _enum, JType backingType) {
JClass lookupType = _enum.owner().ref(Map.class).narrow(backingType.boxify(), _enum);
JFieldVar lookupMap = _enum.field(JMod.PRIVATE | JMod.STATIC | JMod.FINAL, lookupType, "CONSTANTS");
JClass lookupImplType = _enum.owner().ref(HashMap.class).narrow(backingType.boxify(), _enum);
lookupMap.init(JExpr._new(lookupImplType));
JForEach forEach = _enum.init().forEach(_enum, "c", JExpr.invoke("values"));
JInvocation put = forEach.body().invoke(lookupMap, "put");
put.arg(forEach.var().ref("value"));
put.arg(forEach.var());
return lookupMap;
}
private JFieldVar addValueField(JDefinedClass _enum, JType type) {
JFieldVar valueField = _enum.field(JMod.PRIVATE | JMod.FINAL, type, VALUE_FIELD_NAME);
JMethod constructor = _enum.constructor(JMod.PRIVATE);
JVar valueParam = constructor.param(type, VALUE_FIELD_NAME);
JBlock body = constructor.body();
body.assign(JExpr._this().ref(valueField), valueParam);
return valueField;
}
private void addToString(JDefinedClass _enum, JFieldVar valueField) {
JMethod toString = _enum.method(JMod.PUBLIC, String.class, "toString");
JBlock body = toString.body();
JExpression toReturn = JExpr._this().ref(valueField);
if(!isString(valueField.type())){
toReturn = toReturn.plus(JExpr.lit(""));
}
body._return(toReturn);
toString.annotate(Override.class);
}
private void addValueMethod(JDefinedClass _enum, JFieldVar valueField) {
JMethod fromValue = _enum.method(JMod.PUBLIC, valueField.type(), "value");
JBlock body = fromValue.body();
body._return(JExpr._this().ref(valueField));
ruleFactory.getAnnotator().enumValueMethod(fromValue);
}
private boolean isString(JType type){
return type.fullName().equals(String.class.getName());
}
private void addEnumConstants(JsonNode node, JDefinedClass _enum, JsonNode customNames, JType type) {
Collection existingConstantNames = new ArrayList();
for (int i = 0; i < node.size(); i++) {
JsonNode value = node.path(i);
if (!value.isNull()) {
String constantName = getConstantName(value.asText(), customNames.path(i).asText());
constantName = makeUnique(constantName, existingConstantNames);
existingConstantNames.add(constantName);
JEnumConstant constant = _enum.enumConstant(constantName);
constant.arg(DefaultRule.getDefaultValue(type, value));
ruleFactory.getAnnotator().enumConstant(constant, value.asText());
}
}
}
private String getEnumName(String nodeName, JsonNode node, JClassContainer container) {
String fieldName = ruleFactory.getNameHelper().getFieldName(nodeName, node);
String className = ruleFactory.getNameHelper().replaceIllegalCharacters(capitalize(fieldName));
String normalizedName = ruleFactory.getNameHelper().normalizeName(className);
Collection existingClassNames = new ArrayList();
for (Iterator classes = container.classes(); classes.hasNext();) {
existingClassNames.add(classes.next().name());
}
return makeUnique(normalizedName, existingClassNames);
}
private String makeUnique(String name, Collection existingNames) {
boolean found = false;
for (String existingName : existingNames) {
if (name.equalsIgnoreCase(existingName)) {
found = true;
break;
}
}
if (found) {
name = makeUnique(name + "_", existingNames);
}
return name;
}
protected String getConstantName(String nodeName, String customName) {
if (isNotBlank(customName)) {
return customName;
}
List enumNameGroups = new ArrayList(asList(splitByCharacterTypeCamelCase(nodeName)));
String enumName = "";
for (Iterator iter = enumNameGroups.iterator(); iter.hasNext();) {
if (containsOnly(ruleFactory.getNameHelper().replaceIllegalCharacters(iter.next()), "_")) {
iter.remove();
}
}
enumName = upperCase(join(enumNameGroups, "_"));
if (isEmpty(enumName)) {
enumName = "__EMPTY__";
} else if (Character.isDigit(enumName.charAt(0))) {
enumName = "_" + enumName;
}
return enumName;
}
private void addInterfaces(JDefinedClass jclass, JsonNode javaInterfaces) {
for (JsonNode i : javaInterfaces) {
jclass._implements(resolveType(jclass._package(), i.asText()));
}
}
}