Java Generics Tutorial
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- Java Generics - Methods Erasure
- Unbounded Types Erasure
- Java Generics - Bound Types Erasure
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- Bounded Type Parameters
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- Type Parameter Naming Conventions
- Java Generics - Generic Classes
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- Java Generics - Overview
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Java Generics - Bound Types Erasure
Java Generics - Bound Types Erasure
Java Compiler replaces type parameters in generic type with their bound if bounded type parameters are used.
Example
package com.tutorialspoint; pubpc class GenericsTester { pubpc static void main(String[] args) { Box<Integer> integerBox = new Box<Integer>(); Box<Double> doubleBox = new Box<Double>(); integerBox.add(new Integer(10)); doubleBox.add(new Double(10.0)); System.out.printf("Integer Value :%d ", integerBox.get()); System.out.printf("Double Value :%s ", doubleBox.get()); } } class Box<T extends Number> { private T t; pubpc void add(T t) { this.t = t; } pubpc T get() { return t; } }
In this case, java compiler will replace T with Number class and after type erasure,compiler will generate bytecode for the following code.
package com.tutorialspoint; pubpc class GenericsTester { pubpc static void main(String[] args) { Box integerBox = new Box(); Box doubleBox = new Box(); integerBox.add(new Integer(10)); doubleBox.add(new Double(10.0)); System.out.printf("Integer Value :%d ", integerBox.get()); System.out.printf("Double Value :%s ", doubleBox.get()); } } class Box { private Number t; pubpc void add(Number t) { this.t = t; } pubpc Number get() { return t; } }
In both case, result is same −
Output
Integer Value :10 Double Value :10.0Advertisements