Java Generics 简明教程
Java Generics - Classes
泛型类声明看起来像非泛型类声明，除了类名后跟类型参数部分。
A generic class declaration looks like a non-generic class declaration, except that the class name is followed by a type parameter section.
泛型类的类型参数部分可以包含一个或多个用逗号分隔的类型参数。这些类被称为参数化类或参数化类型，因为它们接受一个或多个参数。
The type parameter section of a generic class can have one or more type parameters separated by commas. These classes are known as parameterized classes or parameterized types because they accept one or more parameters.
Syntax
public class Box<T> {
private T t;
}其中
Where
-
Box − Box is a generic class.
-
T − The generic type parameter passed to generic class. It can take any Object.
-
t − Instance of generic type T.
Description
T 是传递给泛型类框的类型参数，并且应该在创建框对象时传递。
The T is a type parameter passed to the generic class Box and should be passed when a Box object is created.
Example
使用任意你选择的编辑器创建以下 Java 程序。
Create the following java program using any editor of your choice.
GenericsTester.java
package com.tutorialspoint;
public class GenericsTester {
public static void main(String[] args) {
Box<Integer> integerBox = new Box<Integer>();
Box<String> stringBox = new Box<String>();
integerBox.add(new Integer(10));
stringBox.add(new String("Hello World"));
System.out.printf("Integer Value :%d\n", integerBox.get());
System.out.printf("String Value :%s\n", stringBox.get());
}
}
class Box<T> {
private T t;
public void add(T t) {
this.t = t;
}
public T get() {
return t;
}
}这将产生以下结果。
This will produce the following result.