Constructor.java
/**
* Copyright (c) 2008, SnakeYAML
*
* 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.yaml.snakeyaml.constructor;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import org.yaml.snakeyaml.LoaderOptions;
import org.yaml.snakeyaml.TypeDescription;
import org.yaml.snakeyaml.error.YAMLException;
import org.yaml.snakeyaml.introspector.Property;
import org.yaml.snakeyaml.nodes.MappingNode;
import org.yaml.snakeyaml.nodes.Node;
import org.yaml.snakeyaml.nodes.NodeId;
import org.yaml.snakeyaml.nodes.NodeTuple;
import org.yaml.snakeyaml.nodes.ScalarNode;
import org.yaml.snakeyaml.nodes.SequenceNode;
import org.yaml.snakeyaml.nodes.Tag;
import org.yaml.snakeyaml.util.EnumUtils;
/**
* Construct a custom Java instance.
*/
public class Constructor extends SafeConstructor {
/**
* Create with options
*
* @param loadingConfig - config
*/
public Constructor(LoaderOptions loadingConfig) {
this(Object.class, loadingConfig);
}
/**
* Create
*
* @param theRoot - the class to create (to be the root of the YAML document)
* @param loadingConfig - options
*/
public Constructor(Class<? extends Object> theRoot, LoaderOptions loadingConfig) {
this(new TypeDescription(checkRoot(theRoot)), null, loadingConfig);
}
/**
* Ugly Java way to check the argument in the constructor
*/
private static Class<? extends Object> checkRoot(Class<? extends Object> theRoot) {
if (theRoot == null) {
throw new NullPointerException("Root class must be provided.");
} else {
return theRoot;
}
}
/**
* Create
*
* @param theRoot - the root class to create
* @param loadingConfig options
*/
public Constructor(TypeDescription theRoot, LoaderOptions loadingConfig) {
this(theRoot, null, loadingConfig);
}
/**
* Create with all possible arguments
*
* @param theRoot - the class (usually JavaBean) to be constructed
* @param moreTDs - collection of classes used by the root class
* @param loadingConfig - configuration
*/
public Constructor(TypeDescription theRoot, Collection<TypeDescription> moreTDs,
LoaderOptions loadingConfig) {
super(loadingConfig);
if (theRoot == null) {
throw new NullPointerException("Root type must be provided.");
}
// register a general Construct when the explicit one was not found
this.yamlConstructors.put(null, new ConstructYamlObject());
// register the root tag to begin with its Construct
if (!Object.class.equals(theRoot.getType())) {
rootTag = new Tag(theRoot.getType());
}
yamlClassConstructors.put(NodeId.scalar, new ConstructScalar());
yamlClassConstructors.put(NodeId.mapping, new ConstructMapping());
yamlClassConstructors.put(NodeId.sequence, new ConstructSequence());
addTypeDescription(theRoot);
if (moreTDs != null) {
for (TypeDescription td : moreTDs) {
addTypeDescription(td);
}
}
}
/**
* Create
*
* @param theRoot - the main class to crate
* @param loadingConfig - options
* @throws ClassNotFoundException if something goes wrong
*/
public Constructor(String theRoot, LoaderOptions loadingConfig) throws ClassNotFoundException {
this(Class.forName(check(theRoot)), loadingConfig);
}
private static String check(String s) {
if (s == null) {
throw new NullPointerException("Root type must be provided.");
}
if (s.trim().isEmpty()) {
throw new YAMLException("Root type must be provided.");
}
return s;
}
/**
* Construct mapping instance (Map, JavaBean) when the runtime class is known.
*/
protected class ConstructMapping implements Construct {
/**
* Construct JavaBean. If type safe collections are used please look at
* <code>TypeDescription</code>.
*
* @param node node where the keys are property names (they can only be <code>String</code>s)
* and values are objects to be created
* @return constructed JavaBean
*/
public Object construct(Node node) {
MappingNode mnode = (MappingNode) node;
if (Map.class.isAssignableFrom(node.getType())) {
if (node.isTwoStepsConstruction()) {
return newMap(mnode);
} else {
return constructMapping(mnode);
}
} else if (Collection.class.isAssignableFrom(node.getType())) {
if (node.isTwoStepsConstruction()) {
return newSet(mnode);
} else {
return constructSet(mnode);
}
} else {
Object obj = Constructor.this.newInstance(mnode);
if (obj != NOT_INSTANTIATED_OBJECT) {
if (node.isTwoStepsConstruction()) {
return obj;
} else {
return constructJavaBean2ndStep(mnode, obj);
}
} else {
throw new ConstructorException(null, null,
"Can't create an instance for " + mnode.getTag(), node.getStartMark());
}
}
}
@SuppressWarnings("unchecked")
public void construct2ndStep(Node node, Object object) {
if (Map.class.isAssignableFrom(node.getType())) {
constructMapping2ndStep((MappingNode) node, (Map<Object, Object>) object);
} else if (Set.class.isAssignableFrom(node.getType())) {
constructSet2ndStep((MappingNode) node, (Set<Object>) object);
} else {
constructJavaBean2ndStep((MappingNode) node, object);
}
}
// protected Object createEmptyJavaBean(MappingNode node) {
// try {
// Object instance = Constructor.this.newInstance(node);
// if (instance != null) {
// return instance;
// }
//
// /**
// * Using only default constructor. Everything else will be
// * initialized on 2nd step. If we do here some partial
// * initialization, how do we then track what need to be done on
// * 2nd step? I think it is better to get only object here (to
// * have it as reference for recursion) and do all other thing on
// * 2nd step.
// */
// java.lang.reflect.Constructor<?> c =
// node.getType().getDeclaredConstructor();
// c.setAccessible(true);
// return c.newInstance();
// } catch (Exception e) {
// throw new YAMLException(e);
// }
// }
protected Object constructJavaBean2ndStep(MappingNode node, Object object) {
flattenMapping(node, true);
Class<? extends Object> beanType = node.getType();
List<NodeTuple> nodeValue = node.getValue();
for (NodeTuple tuple : nodeValue) {
Node valueNode = tuple.getValueNode();
// flattenMapping enforces keys to be Strings
String key = (String) constructObject(tuple.getKeyNode());
try {
TypeDescription memberDescription = typeDefinitions.get(beanType);
Property property = memberDescription == null ? getProperty(beanType, key)
: memberDescription.getProperty(key);
if (!property.isWritable()) {
throw new YAMLException(
"No writable property '" + key + "' on class: " + beanType.getName());
}
valueNode.setType(property.getType());
final boolean typeDetected =
memberDescription != null && memberDescription.setupPropertyType(key, valueNode);
if (!typeDetected && valueNode.getNodeId() != NodeId.scalar) {
// only if there is no explicit TypeDescription
Class<?>[] arguments = property.getActualTypeArguments();
if (arguments != null && arguments.length > 0) {
// type safe (generic) collection may contain the
// proper class
if (valueNode.getNodeId() == NodeId.sequence) {
Class<?> t = arguments[0];
SequenceNode snode = (SequenceNode) valueNode;
snode.setListType(t);
} else if (Map.class.isAssignableFrom(valueNode.getType())) {
Class<?> keyType = arguments[0];
Class<?> valueType = arguments[1];
MappingNode mnode = (MappingNode) valueNode;
mnode.setTypes(keyType, valueType);
mnode.setUseClassConstructor(true);
} else if (Collection.class.isAssignableFrom(valueNode.getType())) {
Class<?> t = arguments[0];
MappingNode mnode = (MappingNode) valueNode;
mnode.setOnlyKeyType(t);
mnode.setUseClassConstructor(true);
}
}
}
Object value =
(memberDescription != null) ? newInstance(memberDescription, key, valueNode)
: constructObject(valueNode);
// Correct when the property expects float but double was
// constructed
if ((property.getType() == Float.TYPE || property.getType() == Float.class)
&& (value instanceof Double)) {
value = ((Double) value).floatValue();
}
// Correct when the property a String but the value is binary
if (property.getType() == String.class && Tag.BINARY.equals(valueNode.getTag())
&& value instanceof byte[]) {
value = new String((byte[]) value);
}
if (memberDescription == null || !memberDescription.setProperty(object, key, value)) {
property.set(object, value);
}
} catch (DuplicateKeyException e) {
throw e;
} catch (Exception e) {
throw new ConstructorException(
"Cannot create property=" + key + " for JavaBean=" + object, node.getStartMark(),
e.getMessage(), valueNode.getStartMark(), e);
}
}
return object;
}
private Object newInstance(TypeDescription memberDescription, String propertyName, Node node) {
Object newInstance = memberDescription.newInstance(propertyName, node);
if (newInstance != null) {
constructedObjects.put(node, newInstance);
return constructObjectNoCheck(node);
}
return constructObject(node);
}
protected Property getProperty(Class<? extends Object> type, String name) {
return getPropertyUtils().getProperty(type, name);
}
}
/**
* Construct an instance when the runtime class is not known but a global tag with a class name is
* defined. It delegates the construction to the appropriate constructor based on the node kind
* (scalar, sequence, mapping)
*/
protected class ConstructYamlObject implements Construct {
private Construct getConstructor(Node node) {
Class<?> cl = getClassForNode(node);
node.setType(cl);
// call the constructor as if the runtime class is defined
Construct constructor = yamlClassConstructors.get(node.getNodeId());
return constructor;
}
public Object construct(Node node) {
try {
return getConstructor(node).construct(node);
} catch (ConstructorException e) {
throw e;
} catch (Exception e) {
throw new ConstructorException(null, null,
"Can't construct a java object for " + node.getTag() + "; exception=" + e.getMessage(),
node.getStartMark(), e);
}
}
public void construct2ndStep(Node node, Object object) {
try {
getConstructor(node).construct2ndStep(node, object);
} catch (Exception e) {
throw new ConstructorException(null, null,
"Can't construct a second step for a java object for " + node.getTag() + "; exception="
+ e.getMessage(),
node.getStartMark(), e);
}
}
}
/**
* Construct scalar instance when the runtime class is known. Recursive structures are not
* supported.
*/
protected class ConstructScalar extends AbstractConstruct {
public Object construct(Node nnode) {
ScalarNode node = (ScalarNode) nnode;
Class<?> type = node.getType();
// In case there is TypeDefinition for the 'type'
Object instance = newInstance(type, node, false);
if (instance != NOT_INSTANTIATED_OBJECT) {
return instance;
}
Object result;
if (type.isPrimitive() || type == String.class || Number.class.isAssignableFrom(type)
|| type == Boolean.class || Date.class.isAssignableFrom(type) || type == Character.class
|| type == BigInteger.class || type == BigDecimal.class
|| Enum.class.isAssignableFrom(type) || Tag.BINARY.equals(node.getTag())
|| Calendar.class.isAssignableFrom(type) || type == UUID.class) {
// standard classes created directly
result = constructStandardJavaInstance(type, node);
} else {
// there must be only 1 constructor with 1 argument
java.lang.reflect.Constructor<?>[] javaConstructors = type.getDeclaredConstructors();
int oneArgCount = 0;
java.lang.reflect.Constructor<?> javaConstructor = null;
for (java.lang.reflect.Constructor<?> c : javaConstructors) {
if (c.getParameterTypes().length == 1) {
oneArgCount++;
javaConstructor = c;
}
}
Object argument;
if (javaConstructor == null) {
throw new YAMLException("No single argument constructor found for " + type);
} else if (oneArgCount == 1) {
argument = constructStandardJavaInstance(javaConstructor.getParameterTypes()[0], node);
} else {
// TODO it should be possible to use implicit types instead
// of forcing String. Resolver must be available here to
// obtain the implicit tag. Then we can set the tag and call
// callConstructor(node) to create the argument instance.
// On the other hand it may be safer to require a custom
// constructor to avoid guessing the argument class
argument = constructScalar(node);
try {
javaConstructor = type.getDeclaredConstructor(String.class);
} catch (Exception e) {
throw new YAMLException("Can't construct a java object for scalar " + node.getTag()
+ "; No String constructor found. Exception=" + e.getMessage(), e);
}
}
try {
javaConstructor.setAccessible(true);
result = javaConstructor.newInstance(argument);
} catch (Exception e) {
throw new ConstructorException(null, null, "Can't construct a java object for scalar "
+ node.getTag() + "; exception=" + e.getMessage(), node.getStartMark(), e);
}
}
return result;
}
@SuppressWarnings("unchecked")
private Object constructStandardJavaInstance(@SuppressWarnings("rawtypes") Class type,
ScalarNode node) {
Object result;
if (type == String.class) {
Construct stringConstructor = yamlConstructors.get(Tag.STR);
result = stringConstructor.construct(node);
} else if (type == Boolean.class || type == Boolean.TYPE) {
Construct boolConstructor = yamlConstructors.get(Tag.BOOL);
result = boolConstructor.construct(node);
} else if (type == Character.class || type == Character.TYPE) {
Construct charConstructor = yamlConstructors.get(Tag.STR);
String ch = (String) charConstructor.construct(node);
if (ch.isEmpty()) {
result = null;
} else if (ch.length() != 1) {
throw new YAMLException("Invalid node Character: '" + ch + "'; length: " + ch.length());
} else {
result = Character.valueOf(ch.charAt(0));
}
} else if (Date.class.isAssignableFrom(type)) {
Construct dateConstructor = yamlConstructors.get(Tag.TIMESTAMP);
Date date = (Date) dateConstructor.construct(node);
if (type == Date.class) {
result = date;
} else {
try {
java.lang.reflect.Constructor<?> constr = type.getConstructor(long.class);
result = constr.newInstance(date.getTime());
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new YAMLException("Cannot construct: '" + type + "'");
}
}
} else if (type == Float.class || type == Double.class || type == Float.TYPE
|| type == Double.TYPE || type == BigDecimal.class) {
if (type == BigDecimal.class) {
result = new BigDecimal(node.getValue());
} else {
Construct doubleConstructor = yamlConstructors.get(Tag.FLOAT);
result = doubleConstructor.construct(node);
if (type == Float.class || type == Float.TYPE) {
result = Float.valueOf(((Double) result).floatValue());
}
}
} else if (type == Byte.class || type == Short.class || type == Integer.class
|| type == Long.class || type == BigInteger.class || type == Byte.TYPE
|| type == Short.TYPE || type == Integer.TYPE || type == Long.TYPE) {
Construct intConstructor = yamlConstructors.get(Tag.INT);
result = intConstructor.construct(node);
if (type == Byte.class || type == Byte.TYPE) {
result = Integer.valueOf(result.toString()).byteValue();
} else if (type == Short.class || type == Short.TYPE) {
result = Integer.valueOf(result.toString()).shortValue();
} else if (type == Integer.class || type == Integer.TYPE) {
result = Integer.parseInt(result.toString());
} else if (type == Long.class || type == Long.TYPE) {
result = Long.valueOf(result.toString());
} else {
// only BigInteger left
result = new BigInteger(result.toString());
}
} else if (Enum.class.isAssignableFrom(type)) {
String enumValueName = node.getValue();
try {
if (loadingConfig.isEnumCaseSensitive()) {
result = Enum.valueOf(type, enumValueName);
} else {
result = EnumUtils.findEnumInsensitiveCase(type, enumValueName);
}
} catch (Exception ex) {
throw new YAMLException("Unable to find enum value '" + enumValueName
+ "' for enum class: " + type.getName());
}
} else if (Calendar.class.isAssignableFrom(type)) {
ConstructYamlTimestamp contr = new ConstructYamlTimestamp();
contr.construct(node);
result = contr.getCalendar();
} else if (Number.class.isAssignableFrom(type)) {
// since we do not know the exact type we create Float
ConstructYamlFloat contr = new ConstructYamlFloat();
result = contr.construct(node);
} else if (UUID.class == type) {
result = UUID.fromString(node.getValue());
} else {
if (yamlConstructors.containsKey(node.getTag())) {
result = yamlConstructors.get(node.getTag()).construct(node);
} else {
throw new YAMLException("Unsupported class: " + type);
}
}
return result;
}
}
/**
* Construct sequence (List, Array, or immutable object) when the runtime class is known.
*/
protected class ConstructSequence implements Construct {
@SuppressWarnings("unchecked")
public Object construct(Node node) {
SequenceNode snode = (SequenceNode) node;
if (Set.class.isAssignableFrom(node.getType())) {
if (node.isTwoStepsConstruction()) {
throw new YAMLException("Set cannot be recursive.");
} else {
return constructSet(snode);
}
} else if (Collection.class.isAssignableFrom(node.getType())) {
if (node.isTwoStepsConstruction()) {
return newList(snode);
} else {
return constructSequence(snode);
}
} else if (node.getType().isArray()) {
if (node.isTwoStepsConstruction()) {
return createArray(node.getType(), snode.getValue().size());
} else {
return constructArray(snode);
}
} else {
// create immutable object
List<java.lang.reflect.Constructor<?>> possibleConstructors =
new ArrayList<java.lang.reflect.Constructor<?>>(snode.getValue().size());
for (java.lang.reflect.Constructor<?> constructor : node.getType()
.getDeclaredConstructors()) {
if (snode.getValue().size() == constructor.getParameterTypes().length) {
possibleConstructors.add(constructor);
}
}
if (!possibleConstructors.isEmpty()) {
if (possibleConstructors.size() == 1) {
Object[] argumentList = new Object[snode.getValue().size()];
java.lang.reflect.Constructor<?> c = possibleConstructors.get(0);
int index = 0;
for (Node argumentNode : snode.getValue()) {
Class<?> type = c.getParameterTypes()[index];
// set runtime classes for arguments
argumentNode.setType(type);
argumentList[index++] = constructObject(argumentNode);
}
try {
c.setAccessible(true);
return c.newInstance(argumentList);
} catch (Exception e) {
throw new YAMLException(e);
}
}
// use BaseConstructor
List<Object> argumentList = (List<Object>) constructSequence(snode);
Class<?>[] parameterTypes = new Class[argumentList.size()];
int index = 0;
for (Object parameter : argumentList) {
parameterTypes[index] = parameter.getClass();
index++;
}
for (java.lang.reflect.Constructor<?> c : possibleConstructors) {
Class<?>[] argTypes = c.getParameterTypes();
boolean foundConstructor = true;
for (int i = 0; i < argTypes.length; i++) {
if (!wrapIfPrimitive(argTypes[i]).isAssignableFrom(parameterTypes[i])) {
foundConstructor = false;
break;
}
}
if (foundConstructor) {
try {
c.setAccessible(true);
return c.newInstance(argumentList.toArray());
} catch (Exception e) {
throw new YAMLException(e);
}
}
}
}
throw new YAMLException("No suitable constructor with " + snode.getValue().size()
+ " arguments found for " + node.getType());
}
}
private Class<? extends Object> wrapIfPrimitive(Class<?> clazz) {
if (!clazz.isPrimitive()) {
return clazz;
}
if (clazz == Integer.TYPE) {
return Integer.class;
}
if (clazz == Float.TYPE) {
return Float.class;
}
if (clazz == Double.TYPE) {
return Double.class;
}
if (clazz == Boolean.TYPE) {
return Boolean.class;
}
if (clazz == Long.TYPE) {
return Long.class;
}
if (clazz == Character.TYPE) {
return Character.class;
}
if (clazz == Short.TYPE) {
return Short.class;
}
if (clazz == Byte.TYPE) {
return Byte.class;
}
throw new YAMLException("Unexpected primitive " + clazz);
}
@SuppressWarnings("unchecked")
public void construct2ndStep(Node node, Object object) {
SequenceNode snode = (SequenceNode) node;
if (List.class.isAssignableFrom(node.getType())) {
List<Object> list = (List<Object>) object;
constructSequenceStep2(snode, list);
} else if (node.getType().isArray()) {
constructArrayStep2(snode, object);
} else {
throw new YAMLException("Immutable objects cannot be recursive.");
}
}
}
protected Class<?> getClassForNode(Node node) {
Class<? extends Object> classForTag = typeTags.get(node.getTag());
if (classForTag == null) {
String name = node.getTag().getClassName();
Class<?> cl;
try {
cl = getClassForName(name);
} catch (ClassNotFoundException e) {
throw new YAMLException("Class not found: " + name);
}
typeTags.put(node.getTag(), cl);
return cl;
} else {
return classForTag;
}
}
protected Class<?> getClassForName(String name) throws ClassNotFoundException {
try {
return Class.forName(name, true, Thread.currentThread().getContextClassLoader());
} catch (ClassNotFoundException e) {
return Class.forName(name);
}
}
}