Question

我正在使用lambda表达式，并试图创建一个通用的函数接口，该接口采用双精度值并将其返回为整数值。但是，然后我得到一个错误NumberFormatException或无法强制转换。如果我使用（int）（Math.random）之类的方法，则它将双精度值完美地转换为整数，但这是我的代码和出现的错误：

package Exercise;    
public class Training {     

    public static void main(String[] args) {

        Training4<Integer, Double> obj = (x) -> Integer.parseInt(x.toString());
        System.out.println(obj.constrmeth(10.5));
    }
}

这是功能界面：

package Exercise;
public interface Training4 <T, S>{

    T constrmeth(S a);
}

错误：

Exception in thread "main" java.lang.NumberFormatException: For input string: "10.5"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at Exercise.Training.lambda$0(Training.java:9)
at Exercise.Training.main(Training.java:10)

Answer 1

 **Here if you use Double then you can easily get int value **   

package com.example.demo;

public class TEST {

    public static void main(String[] args) {




            Training4 obj = (x) -> x.intValue();
            System.out.println(obj.constrmeth(10.5));


    }

}

 interface Training4 {

public  Integer constrmeth(Double db);


}

无法将Double解析为Integer

1 个答案: