JAVA JDKでのデザインモード

You can find an overview of a lot design patterns in  Wikipedia . It also mentions which patterns are mentioned by GoF. I'll sum them up here and try to assign as much as possible pattern implementations found in both the Java SE and Java EE API's.
Creational patterns
Abstract factory  (recognizeable by creational methods returning an abstract/interface type)
java.util.Calendar#getInstance()
java.util.Arrays#asList()
java.util.ResourceBundle#getBundle()
java.net.URL#openConnection()
java.sql.DriverManager#getConnection()
java.sql.Connection#createStatement()
java.sql.Statement#executeQuery()
java.text.NumberFormat#getInstance()
java.lang.management.ManagementFactory  (all  getXXX()  methods)
java.nio.charset.Charset#forName()
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
Factory method  (recognizeable by creational methods returning a concrete type)
java.lang.Object#toString()  (overrideable in all subclasses)
java.lang.Class#newInstance()
java.lang.Integer#valueOf(String)  (also on  Boolean ,  Byte ,  Character ,  Short ,  Long , Float  and  Double )
java.lang.Class#forName()
java.lang.reflect.Array#newInstance()
java.lang.reflect.Constructor#newInstance()
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()
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.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<K>, List<V>)  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)
java.util.Map#putAll(Map)
java.util.List#addAll(Collection)
java.util.Set#addAll(Collection)
java.nio.ByteBuffer#put(ByteBuffer)  (also on  CharBuffer ,  ShortBuffer ,  IntBuffer , LongBuffer ,  FloatBuffer  and  DoubleBuffer )
java.awt.Container#add(Component)  (practically all over Swing thus)
Decorator  (recognizeable by creational methods taking an instance of same abstract/interface type)
All subclasses of  java.io.InputStream ,  OutputStream ,  Reader  and  Writer  have a constructor taking an instance of same type.
Almost all implementations of  java.util.List ,  Set  and  Map  have a constructor taking an instance of same type.
java.util.Collections , the  checkedXXX() ,  synchronizedXXX()  and  unmodifiableXXX() methods.
javax.servlet.http.HttpServletRequestWrapper  and  HttpServletResponseWrapper
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 , font-size: 14px; vertical-