如果使用无边界类型参数,则Java Compiler会将通用类型的类型参数替换为对象,如果将绑定参数用作方法参数,则Java Type会将类型参数替换为type。
package com.learnfk; 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")); printBox(integerBox); printBox1(stringBox); } private static <T extends Box> void printBox(T box) { System.out.println("Integer Value :" + box.get()); } private static <T> void printBox1(T box) { System.out.println("String Value :" + ((Box)box).get()); } } class Box<T> { private T t; public void add(T t) { this.t = t; } public T get() { return t; } }
在这种情况下,java编译器将T用对象类替换,并且在类型擦除之后,编译器将为以下代码生成字节码。
package com.learnfk; public class GenericsTester { public static void main(String[] args) { Box integerBox = new Box(); Box stringBox = new Box(); integerBox.add(new Integer(10)); stringBox.add(new String("Hello World")); printBox(integerBox); printBox1(stringBox); } //有界类型擦除 private static void printBox(Box box) { System.out.println("Integer Value :" + box.get()); } //无界类型擦除 private static void printBox1(Object box) { System.out.println("String Value :" + ((Box)box).get()); } } class Box { private Object t; public void add(Object t) { this.t = t; } public Object get() { return t; } }
在两种情况下,输出都是相同的-
链接:https://www.learnfk.comhttps://www.learnfk.com/java-generics/java-generics-method-erasure.html
来源:LearnFk无涯教程网
Integer Value :10 String Value :Hello World
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