Yaml.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;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.regex.Pattern;
import org.yaml.snakeyaml.DumperOptions.FlowStyle;
import org.yaml.snakeyaml.composer.Composer;
import org.yaml.snakeyaml.constructor.BaseConstructor;
import org.yaml.snakeyaml.constructor.Constructor;
import org.yaml.snakeyaml.emitter.Emitable;
import org.yaml.snakeyaml.emitter.Emitter;
import org.yaml.snakeyaml.error.YAMLException;
import org.yaml.snakeyaml.events.Event;
import org.yaml.snakeyaml.introspector.BeanAccess;
import org.yaml.snakeyaml.nodes.Node;
import org.yaml.snakeyaml.nodes.Tag;
import org.yaml.snakeyaml.parser.Parser;
import org.yaml.snakeyaml.parser.ParserImpl;
import org.yaml.snakeyaml.reader.StreamReader;
import org.yaml.snakeyaml.reader.UnicodeReader;
import org.yaml.snakeyaml.representer.Representer;
import org.yaml.snakeyaml.resolver.Resolver;
import org.yaml.snakeyaml.serializer.Serializer;
/**
* Public YAML interface. This class is not thread-safe. Which means that all the methods of the
* same instance can be called only by one thread. It is better to create an instance for every YAML
* stream.
*/
public class Yaml {
protected final Resolver resolver;
private String name;
protected BaseConstructor constructor;
protected Representer representer;
protected DumperOptions dumperOptions;
protected LoaderOptions loadingConfig;
/**
* Create Yaml instance.
*/
public Yaml() {
this(new Constructor(new LoaderOptions()), new Representer(new DumperOptions()));
}
/**
* Create Yaml instance.
*
* @param dumperOptions DumperOptions to configure outgoing objects
*/
public Yaml(DumperOptions dumperOptions) {
this(new Constructor(new LoaderOptions()), new Representer(dumperOptions), dumperOptions);
}
/**
* Create Yaml instance.
*
* @param loadingConfig LoadingConfig to control load behavior
*/
public Yaml(LoaderOptions loadingConfig) {
this(new Constructor(loadingConfig), new Representer(new DumperOptions()), new DumperOptions(),
loadingConfig);
}
/**
* Create Yaml instance.
*
* @param representer Representer to emit outgoing objects
*/
public Yaml(Representer representer) {
this(new Constructor(new LoaderOptions()), representer);
}
/**
* Create Yaml instance.
*
* @param constructor BaseConstructor to construct incoming documents
*/
public Yaml(BaseConstructor constructor) {
this(constructor, new Representer(new DumperOptions()));
}
/**
* Create Yaml instance.
*
* @param constructor BaseConstructor to construct incoming documents
* @param representer Representer to emit outgoing objects
*/
public Yaml(BaseConstructor constructor, Representer representer) {
this(constructor, representer, initDumperOptions(representer));
}
private static DumperOptions initDumperOptions(Representer representer) {
DumperOptions dumperOptions = new DumperOptions();
dumperOptions.setDefaultFlowStyle(representer.getDefaultFlowStyle());
dumperOptions.setDefaultScalarStyle(representer.getDefaultScalarStyle());
dumperOptions
.setAllowReadOnlyProperties(representer.getPropertyUtils().isAllowReadOnlyProperties());
dumperOptions.setTimeZone(representer.getTimeZone());
return dumperOptions;
}
/**
* Create Yaml instance. It is safe to create a few instances and use them in different Threads.
*
* @param representer Representer to emit outgoing objects
* @param dumperOptions DumperOptions to configure outgoing objects
*/
public Yaml(Representer representer, DumperOptions dumperOptions) {
this(new Constructor(new LoaderOptions()), representer, dumperOptions);
}
/**
* Create Yaml instance. It is safe to create a few instances and use them in different Threads.
*
* @param constructor BaseConstructor to construct incoming documents. Its LoaderOptions will be
* used everywhere
* @param representer Representer to emit outgoing objects
* @param dumperOptions DumperOptions to configure outgoing objects
*/
public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions) {
this(constructor, representer, dumperOptions, constructor.getLoadingConfig(), new Resolver());
}
/**
* Create Yaml instance. It is safe to create a few instances and use them in different Threads.
*
* @param constructor BaseConstructor to construct incoming documents
* @param representer Representer to emit outgoing objects
* @param dumperOptions DumperOptions to configure outgoing objects
* @param loadingConfig LoadingConfig to control load behavior
*/
public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions,
LoaderOptions loadingConfig) {
this(constructor, representer, dumperOptions, loadingConfig, new Resolver());
}
/**
* Create Yaml instance. It is safe to create a few instances and use them in different Threads.
*
* @param constructor BaseConstructor to construct incoming documents
* @param representer Representer to emit outgoing objects
* @param dumperOptions DumperOptions to configure outgoing objects
* @param resolver Resolver to detect implicit type
*/
public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions,
Resolver resolver) {
this(constructor, representer, dumperOptions, new LoaderOptions(), resolver);
}
/**
* Create Yaml instance. It is safe to create a few instances and use them in different Threads.
*
* @param constructor BaseConstructor to construct incoming documents
* @param representer Representer to emit outgoing objects
* @param dumperOptions DumperOptions to configure outgoing objects
* @param loadingConfig LoadingConfig to control load behavior
* @param resolver Resolver to detect implicit type
*/
public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions,
LoaderOptions loadingConfig, Resolver resolver) {
if (constructor == null) {
throw new NullPointerException("Constructor must be provided");
}
if (representer == null) {
throw new NullPointerException("Representer must be provided");
}
if (dumperOptions == null) {
throw new NullPointerException("DumperOptions must be provided");
}
if (loadingConfig == null) {
throw new NullPointerException("LoaderOptions must be provided");
}
if (resolver == null) {
throw new NullPointerException("Resolver must be provided");
}
if (!constructor.isExplicitPropertyUtils()) {
constructor.setPropertyUtils(representer.getPropertyUtils());
} else if (!representer.isExplicitPropertyUtils()) {
representer.setPropertyUtils(constructor.getPropertyUtils());
}
this.constructor = constructor;
this.constructor.setAllowDuplicateKeys(loadingConfig.isAllowDuplicateKeys());
this.constructor.setWrappedToRootException(loadingConfig.isWrappedToRootException());
if (!dumperOptions.getIndentWithIndicator()
&& dumperOptions.getIndent() <= dumperOptions.getIndicatorIndent()) {
throw new YAMLException("Indicator indent must be smaller then indent.");
}
representer.setDefaultFlowStyle(dumperOptions.getDefaultFlowStyle());
representer.setDefaultScalarStyle(dumperOptions.getDefaultScalarStyle());
representer.getPropertyUtils()
.setAllowReadOnlyProperties(dumperOptions.isAllowReadOnlyProperties());
representer.setTimeZone(dumperOptions.getTimeZone());
this.representer = representer;
this.dumperOptions = dumperOptions;
this.loadingConfig = loadingConfig;
this.resolver = resolver;
this.name = "Yaml:" + System.identityHashCode(this);
}
/**
* Serialize a Java object into a YAML String.
*
* @param data Java object to be Serialized to YAML
* @return YAML String
*/
public String dump(Object data) {
List<Object> list = new ArrayList<Object>(1);
list.add(data);
return dumpAll(list.iterator());
}
/**
* Produce the corresponding representation tree for a given Object.
*
* @param data instance to build the representation tree for
* @return representation tree
* @see <a href="http://yaml.org/spec/1.1/#id859333">Figure 3.1. Processing Overview</a>
*/
public Node represent(Object data) {
return representer.represent(data);
}
/**
* Serialize a sequence of Java objects into a YAML String.
*
* @param data Iterator with Objects
* @return YAML String with all the objects in proper sequence
*/
public String dumpAll(Iterator<? extends Object> data) {
StringWriter buffer = new StringWriter();
dumpAll(data, buffer, null);
return buffer.toString();
}
/**
* Serialize a Java object into a YAML stream.
*
* @param data Java object to be serialized to YAML
* @param output stream to write to
*/
public void dump(Object data, Writer output) {
List<Object> list = new ArrayList<Object>(1);
list.add(data);
dumpAll(list.iterator(), output, null);
}
/**
* Serialize a sequence of Java objects into a YAML stream.
*
* @param data Iterator with Objects
* @param output stream to write to
*/
public void dumpAll(Iterator<? extends Object> data, Writer output) {
dumpAll(data, output, null);
}
private void dumpAll(Iterator<? extends Object> data, Writer output, Tag rootTag) {
Serializer serializer =
new Serializer(new Emitter(output, dumperOptions), resolver, dumperOptions, rootTag);
try {
serializer.open();
while (data.hasNext()) {
Node node = representer.represent(data.next());
serializer.serialize(node);
}
serializer.close();
} catch (IOException e) {
throw new YAMLException(e);
}
}
/**
* <p>
* Serialize a Java object into a YAML string. Override the default root tag with
* <code>rootTag</code>.
* </p>
*
* <p>
* This method is similar to <code>Yaml.dump(data)</code> except that the root tag for the whole
* document is replaced with the given tag. This has two main uses.
* </p>
*
* <p>
* First, if the root tag is replaced with a standard YAML tag, such as <code>Tag.MAP</code>, then
* the object will be dumped as a map. The root tag will appear as <code>!!map</code>, or blank
* (implicit !!map).
* </p>
*
* <p>
* Second, if the root tag is replaced by a different custom tag, then the document appears to be
* a different type when loaded. For example, if an instance of MyClass is dumped with the tag
* !!YourClass, then it will be handled as an instance of YourClass when loaded.
* </p>
*
* @param data Java object to be serialized to YAML
* @param rootTag the tag for the whole YAML document. The tag should be Tag.MAP for a JavaBean to
* make the tag disappear (to use implicit tag !!map). If <code>null</code> is provided
* then the standard tag with the full class name is used.
* @param flowStyle flow style for the whole document. See Chapter 10. Collection Styles
* http://yaml.org/spec/1.1/#id930798. If <code>null</code> is provided then the flow style
* from DumperOptions is used.
* @return YAML String
*/
public String dumpAs(Object data, Tag rootTag, FlowStyle flowStyle) {
FlowStyle oldStyle = representer.getDefaultFlowStyle();
if (flowStyle != null) {
representer.setDefaultFlowStyle(flowStyle);
}
List<Object> list = new ArrayList<Object>(1);
list.add(data);
StringWriter buffer = new StringWriter();
dumpAll(list.iterator(), buffer, rootTag);
representer.setDefaultFlowStyle(oldStyle);
return buffer.toString();
}
/**
* <p>
* Serialize a Java object into a YAML string. Override the default root tag with
* <code>Tag.MAP</code>.
* </p>
* <p>
* This method is similar to <code>Yaml.dump(data)</code> except that the root tag for the whole
* document is replaced with <code>Tag.MAP</code> tag (implicit !!map).
* </p>
* <p>
* Block Mapping is used as the collection style. See 10.2.2. Block Mappings
* (http://yaml.org/spec/1.1/#id934537)
* </p>
*
* @param data Java object to be serialized to YAML
* @return YAML String
*/
public String dumpAsMap(Object data) {
return dumpAs(data, Tag.MAP, FlowStyle.BLOCK);
}
/**
* Serialize (dump) a YAML node into a YAML stream.
*
* @param node YAML node to be serialized to YAML
* @param output stream to write to
*/
public void serialize(Node node, Writer output) {
Serializer serializer =
new Serializer(new Emitter(output, dumperOptions), resolver, dumperOptions, null);
try {
serializer.open();
serializer.serialize(node);
serializer.close();
} catch (IOException e) {
throw new YAMLException(e);
}
}
/**
* Serialize the representation tree into Events.
*
* @param data representation tree
* @return Event list
* @see <a href="http://yaml.org/spec/1.1/#id859333">Processing Overview</a>
*/
public List<Event> serialize(Node data) {
SilentEmitter emitter = new SilentEmitter();
Serializer serializer = new Serializer(emitter, resolver, dumperOptions, null);
try {
serializer.open();
serializer.serialize(data);
serializer.close();
} catch (IOException e) {
throw new YAMLException(e);
}
return emitter.getEvents();
}
private static class SilentEmitter implements Emitable {
private final List<Event> events = new ArrayList<Event>(100);
public List<Event> getEvents() {
return events;
}
@Override
public void emit(Event event) throws IOException {
events.add(event);
}
}
/**
* Parse the only YAML document in a String and produce the corresponding Java object. (Because
* the encoding in known BOM is not respected.)
*
* @param yaml YAML data to load from (BOM must not be present)
* @param <T> the class of the instance to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T load(String yaml) {
return (T) loadFromReader(new StreamReader(yaml), Object.class);
}
/**
* Parse the only YAML document in a stream and produce the corresponding Java object.
*
* @param io data to load from (BOM is respected to detect encoding and removed from the data)
* @param <T> the class of the instance to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T load(InputStream io) {
return (T) loadFromReader(new StreamReader(new UnicodeReader(io)), Object.class);
}
/**
* Parse the only YAML document in a stream and produce the corresponding Java object.
*
* @param io data to load from (BOM must not be present)
* @param <T> the class of the instance to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T load(Reader io) {
return (T) loadFromReader(new StreamReader(io), Object.class);
}
/**
* Parse the only YAML document in a stream and produce the corresponding Java object.
*
* @param <T> Class is defined by the second argument
* @param io data to load from (BOM must not be present)
* @param type Class of the object to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T loadAs(Reader io, Class<? super T> type) {
return (T) loadFromReader(new StreamReader(io), type);
}
/**
* Parse the only YAML document in a String and produce the corresponding Java object. (Because
* the encoding in known BOM is not respected.)
*
* @param <T> Class is defined by the second argument
* @param yaml YAML data to load from (BOM must not be present)
* @param type Class of the object to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T loadAs(String yaml, Class<? super T> type) {
return (T) loadFromReader(new StreamReader(yaml), type);
}
/**
* Parse the only YAML document in a stream and produce the corresponding Java object.
*
* @param <T> Class is defined by the second argument
* @param input data to load from (BOM is respected to detect encoding and removed from the data)
* @param type Class of the object to be created
* @return parsed object
*/
@SuppressWarnings("unchecked")
public <T> T loadAs(InputStream input, Class<? super T> type) {
return (T) loadFromReader(new StreamReader(new UnicodeReader(input)), type);
}
private Object loadFromReader(StreamReader sreader, Class<?> type) {
Composer composer =
new Composer(new ParserImpl(sreader, loadingConfig), resolver, loadingConfig);
constructor.setComposer(composer);
return constructor.getSingleData(type);
}
/**
* Parse all YAML documents in the Reader and produce corresponding Java objects. The documents
* are parsed only when the iterator is invoked.
*
* @param yaml YAML data to load from (BOM must not be present)
* @return an Iterable over the parsed Java objects in this String in proper sequence
*/
public Iterable<Object> loadAll(Reader yaml) {
Composer composer = new Composer(new ParserImpl(new StreamReader(yaml), loadingConfig),
resolver, loadingConfig);
constructor.setComposer(composer);
Iterator<Object> result = new Iterator<Object>() {
@Override
public boolean hasNext() {
return constructor.checkData();
}
@Override
public Object next() {
return constructor.getData();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
return new YamlIterable(result);
}
private static class YamlIterable implements Iterable<Object> {
private final Iterator<Object> iterator;
public YamlIterable(Iterator<Object> iterator) {
this.iterator = iterator;
}
@Override
public Iterator<Object> iterator() {
return iterator;
}
}
/**
* Parse all YAML documents in a String and produce corresponding Java objects. (Because the
* encoding in known BOM is not respected.) The documents are parsed only when the iterator is
* invoked.
*
* @param yaml YAML data to load from (BOM must not be present)
* @return an Iterable over the parsed Java objects in this String in proper sequence
*/
public Iterable<Object> loadAll(String yaml) {
return loadAll(new StringReader(yaml));
}
/**
* Parse all YAML documents in a stream and produce corresponding Java objects. The documents are
* parsed only when the iterator is invoked.
*
* @param yaml YAML data to load from (BOM is respected to detect encoding and removed from the
* data)
* @return an Iterable over the parsed Java objects in this stream in proper sequence
*/
public Iterable<Object> loadAll(InputStream yaml) {
return loadAll(new UnicodeReader(yaml));
}
/**
* Parse the first YAML document in a stream and produce the corresponding representation tree.
* (This is the opposite of the represent() method)
*
* @param yaml YAML document
* @return parsed root Node for the specified YAML document
* @see <a href="http://yaml.org/spec/1.1/#id859333">Figure 3.1. Processing Overview</a>
*/
public Node compose(Reader yaml) {
Composer composer = new Composer(new ParserImpl(new StreamReader(yaml), loadingConfig),
resolver, loadingConfig);
return composer.getSingleNode();
}
/**
* Parse all YAML documents in a stream and produce corresponding representation trees.
*
* @param yaml stream of YAML documents
* @return parsed root Nodes for all the specified YAML documents
* @see <a href="http://yaml.org/spec/1.1/#id859333">Processing Overview</a>
*/
public Iterable<Node> composeAll(Reader yaml) {
final Composer composer = new Composer(new ParserImpl(new StreamReader(yaml), loadingConfig),
resolver, loadingConfig);
Iterator<Node> result = new Iterator<Node>() {
@Override
public boolean hasNext() {
return composer.checkNode();
}
@Override
public Node next() {
Node node = composer.getNode();
if (node != null) {
return node;
} else {
throw new NoSuchElementException("No Node is available.");
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
return new NodeIterable(result);
}
private static class NodeIterable implements Iterable<Node> {
private final Iterator<Node> iterator;
public NodeIterable(Iterator<Node> iterator) {
this.iterator = iterator;
}
@Override
public Iterator<Node> iterator() {
return iterator;
}
}
/**
* Add an implicit scalar detector. If an implicit scalar value matches the given regexp, the
* corresponding tag is assigned to the scalar.
*
* @param tag tag to assign to the node
* @param regexp regular expression to match against
* @param first a sequence of possible initial characters or null (which means any).
*/
public void addImplicitResolver(Tag tag, Pattern regexp, String first) {
resolver.addImplicitResolver(tag, regexp, first);
}
/**
* Add an implicit scalar detector. If an implicit scalar value matches the given regexp, the
* corresponding tag is assigned to the scalar.
*
* @param tag tag to assign to the node
* @param regexp regular expression to match against
* @param first a sequence of possible initial characters or null (which means any).
* @param limit the max length of the value which may match the regular expression
*/
public void addImplicitResolver(Tag tag, Pattern regexp, String first, int limit) {
resolver.addImplicitResolver(tag, regexp, first, limit);
}
@Override
public String toString() {
return name;
}
/**
* Get a meaningful name. It simplifies debugging in a multi-threaded environment. If nothing is
* set explicitly the address of the instance is returned.
*
* @return human readable name
*/
public String getName() {
return name;
}
/**
* Set a meaningful name to be shown in toString()
*
* @param name human readable name
*/
public void setName(String name) {
this.name = name;
}
/**
* Parse a YAML stream and produce parsing events.
*
* @param yaml YAML document(s)
* @return parsed events
* @see <a href="http://yaml.org/spec/1.1/#id859333">Processing Overview</a>
*/
public Iterable<Event> parse(Reader yaml) {
final Parser parser = new ParserImpl(new StreamReader(yaml), loadingConfig);
Iterator<Event> result = new Iterator<Event>() {
@Override
public boolean hasNext() {
return parser.peekEvent() != null;
}
@Override
public Event next() {
Event event = parser.getEvent();
if (event != null) {
return event;
} else {
throw new NoSuchElementException("No Event is available.");
}
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
return new EventIterable(result);
}
private static class EventIterable implements Iterable<Event> {
private final Iterator<Event> iterator;
public EventIterable(Iterator<Event> iterator) {
this.iterator = iterator;
}
@Override
public Iterator<Event> iterator() {
return iterator;
}
}
public void setBeanAccess(BeanAccess beanAccess) {
constructor.getPropertyUtils().setBeanAccess(beanAccess);
representer.getPropertyUtils().setBeanAccess(beanAccess);
}
public void addTypeDescription(TypeDescription td) {
constructor.addTypeDescription(td);
representer.addTypeDescription(td);
}
}