Examples of GoF Design Patterns in Java's core libraries

I am learning GoF Java Design Patterns and I want to see some real life examples of them. What are some good examples of these Design Patterns in Java's core libraries?

You can find an overview of a lot of design patterns in Wikipedia. It also mentions which patterns are mentioned by GoF. I'll sum them up here and try to assign as many pattern implementations as possible, found in both the Java SE and Java EE APIs.

Creational patterns
Abstract factory (recognizeable by creational methods returning the factory itself which in turn can be used to create another abstract/interface type)

• javax.xml.parsers.DocumentBuilderFactory#newInstance()

• javax.xml.transform.TransformerFactory#newInstance()

• javax.xml.xpath.XPathFactory#newInstance()

Builder (recognizeable by creational methods returning the instance itself)

• java.lang.StringBuilder#append() (unsynchronized)

• java.lang.StringBuffer#append() (synchronized)

• java.nio.ByteBuffer#put() (also on CharBuffer, ShortBuffer, IntBuffer, LongBuffer, FloatBuffer and DoubleBuffer)

• javax.swing.GroupLayout.Group#addComponent()

• All implementations of java.lang.Appendable

• java.util.stream.Stream.Builder

Factory method (recognizeable by creational methods returning an implementation of an abstract/interface type)

• java.util.Calendar#getInstance()

• java.util.ResourceBundle#getBundle()

• java.text.NumberFormat#getInstance()

• java.nio.charset.Charset#forName()

• java.net.URLStreamHandlerFactory#createURLStreamHandler(String) (Returns singleton object per protocol)

• java.util.EnumSet#of()

• javax.xml.bind.JAXBContext#createMarshaller() and other similar methods

Prototype (recognizeable by creational methods returning a different instance of itself with the same properties)

• java.lang.Object#clone() (the class has to implement java.lang.Cloneable)

Singleton (recognizeable by creational methods returning the same instance (usually of itself) everytime)

• java.lang.Runtime#getRuntime()

• java.awt.Desktop#getDesktop()

• java.lang.System#getSecurityManager()

Structural patterns
Adapter (recognizeable by creational methods taking an instance of different abstract/interface type and returning an implementation of own/another abstract/interface type which decorates/overrides the given instance)

• java.util.Arrays#asList()

• java.util.Collections#list()

• java.util.Collections#enumeration()

• java.io.InputStreamReader(InputStream) (returns a Reader)

• java.io.OutputStreamWriter(OutputStream) (returns a Writer)

• javax.xml.bind.annotation.adapters.XmlAdapter#marshal() and #unmarshal()

Bridge (recognizeable by creational methods taking an instance of different abstract/interface type and returning an implementation of own abstract/interface type which delegates/uses the given instance)

• None comes to mind yet. A fictive example would be new LinkedHashMap(LinkedHashSet, List) which returns an unmodifiable linked map which doesn't clone the items, but uses them. The java.util.Collections#newSetFromMap() and singletonXXX() methods however comes close.

Composite (recognizeable by behavioral methods taking an instance of same abstract/interface type into a tree structure)

• java.awt.Container#add(Component) (practically all over Swing thus)

• javax.faces.component.UIComponent#getChildren() (practically all over JSF UI thus)

Decorator (recognizeable by creational methods taking an instance of same abstract/interface type which adds additional behaviour)

• All subclasses of java.io.InputStream, OutputStream, Reader and Writer have a constructor taking an instance of same type.

• java.util.Collections, the checkedXXX(), synchronizedXXX() and unmodifiableXXX() methods.

• javax.servlet.http.HttpServletRequestWrapper and HttpServletResponseWrapper

• javax.swing.JScrollPane

Facade (recognizeable by behavioral methods which internally uses instances of different independent abstract/interface types)

• javax.faces.context.FacesContext, it internally uses among others the abstract/interface types LifeCycle, ViewHandler, NavigationHandler and many more without that the enduser has to worry about it (which are however overrideable by injection).

• javax.faces.context.ExternalContext, which internally uses ServletContext, HttpSession, HttpServletRequest, HttpServletResponse, etc.

Flyweight (recognizeable by creational methods returning a cached instance, a bit the "multiton" idea)

• java.lang.Integer#valueOf(int) (also on Boolean, Byte, Character, Short, Long and BigDecimal)

Proxy (recognizeable by creational methods which returns an implementation of given abstract/interface type which in turn delegates/uses a different implementation of given abstract/interface type)

• java.lang.reflect.Proxy

• java.rmi.*

• javax.ejb.EJB (explanation here)

• javax.inject.Inject (explanation here)

• javax.persistence.PersistenceContext

Behavioral patterns
Chain of responsibility (recognizeable by behavioral methods which (indirectly) invokes the same method in another implem

Stack Overflow Q#1673841, score: 3557