java generics tutorial

a generic class of the same type parameter depends on the inheritance architecture of the generic class itself. The list is a subtype of collection, and list can replace collection. This is also true for type declarations with upper and lower bounds. When wildcard characters are used in the type declaration of a generic class, their subtypes can be expanded on two dimensions. such as the collection 2.4 Bridge method Http://www.cnblogs.com/ggjucheng/p/3352519.html 3. Generic class An example of

clutter of the object code that needs to be cast. 2. Use generics to easily find and resolve bugs at compile time Third, the use of rewriting the simple version ArrayListUse generic code as follows:? 123456789101112131415161718192021222324252627282930313233 package javaBasic.generic;/*** 简易版ArrayList*/class ArrListT>{private T obj; public T getObj(){return obj;}public void add(T obj){this.obj = obj;}}public class TestArrayLi

Learning GoalsMastering the use of generic interfacesMastering the definition and use of generic methodsMastering the use of generic arraysMastering nested settings for genericsall of the previous operations are directly using generic operations in the class, and for Java, generics can be defined and used directly in the interface. Defining generic Interfacesafter JDK1.5, not only can you declare a generic

Generics in Java can be said to allow novice confused, and the use of multiple generics at the same time can make a person face. Let's take a look at each situation now.1. Simplest generic examples public class Ttest This is the simplest generic, you can see in the TTest class definition of the place to write a You can see,ttest2. Use of multiple

Java generics are a new feature introduced in JDK 5 that allows the use of type parameters when defining classes and interfaces. generic class Generic classes are the generic forms we use most often, as follows: /** * Tool Class * Created by Yuedong.li on 12/8/15. * * Public class Toolsutil A tool class that is currently used to replace If-else The use of the method is also very simple public class Main

time is taken according to the person type, because Al2 is placed in the AL1, the time is naturally obtained by AL1. The person can receive student, Mycolleciton This method can accept the new collection to store the E-type element, or the subclass of type E, because there is no problem.take when there is no type of security risks, AddAll method Extensibility is strong, supposedly said to write an e can be, and now expand the sub-class is also possible. When do you use this? When stored, the up

Java generics drill-down set useful tools various sets generics drill-down using demo sample, Anonymous inner class, inner class applied to generic discussionSets.javapackage org.rui.generics.set;import Java.util.hashset;import java.util.set;/** * A set useful tool * @author Lenovo * */public class Sets {public staticWatercolors.javapackage org.rui.generics.set;/

Today, the new guy asked me to help you see a bug that prompted classcastexception for the For traversal list.Pseudo code for (Order order:model.getOrderList) ...After debug found orderlist in the object[] array, and then caught the injected positionOrderList = (arraylistGeneric erase, etc. to be continued ...Java generics are fake generics, so annoying this thin

, on the other side is not used (consider backward compatibility);Arraylist// wrongTo ensure that the right and left sides of the generic type is consistent, it is not easy to make mistakes.ArraylistAl.add ("AA"); // wrongBecause the collection-specific object can store either string or other subclasses of object, it is not appropriate to add a specific type object, and type checking can have a security problem. Extendsobject is an indeterminate subtype of object, how can I add objects of a spec

"Let errors be discovered during compilation as much as possible" "You must know the boundary to become a master" --- Thinking in Java Errors are very desirable when being detected during compilation. Java generics are introduced in JDK1.5 to "let the compiler take on more work and ensure that the types are correct ". However, the developer community came along w

the program more secure.In short, generics make our programs more readable and secure through type parameters.How Java generics are implementedErase[Java] View plain copypublic class GenericType {public static void Main (string[] args) {ArraylistArraylistSystem.out.println (Arraystring.getclass () ==arrayinteger.getcl

letter (sometimes multiple generic types with numbers, such as T1,T2), such as many container collections using E, representing element (elements), and map with K for key keys,v to represent values.Two practical applications:(1) Creating a Java file for interface ParentinterfacePackage Edu.tju.cs;public interface parentinterface(2) Creating Java files that implement class ChildClassPackage Edu.tju.cs;publi