Saliya's Blogs

Referring Methods that Throw Exceptions in Java

import java.util.function.Function;

public class PassingMethodsThatThrowExceptions {

    public static int addOne(String value) throws NotANumberException{
        int v = 0;
        try{
            v = Integer.parseInt(value);
        } catch (NumberFormatException e){
            throw new NotANumberException();
        }
        return v+1;
    }

    public static void increment(Function<String,Integer> incrementer, String value){
        System.out.println(incrementer.apply(value));
    }

    public static void main(String[] args) {
        increment(PassingMethodsThatThrowExceptions::addOne, "10");
    }
}

• an addOne function that takes in a String value representing a number then adds 1 to it and returns the result as an int.
• an increment function that simply takes a function, which can perform the increment and a value then apply the function to the value.
• the main method that calls increment with addOne function and value "10"

    Error: java: incompatible thrown types exceptions.NotANumberException in method reference

public class PassingMethodsThatThrowExceptions {
    public interface IncrementerSignature{
        public int apply(String value) throws NotANumberException;
    }

    public static int addOne(String value) throws NotANumberException{
        int v = 0;
        try{
            v = Integer.parseInt(value);
        } catch (NumberFormatException e){
            throw new NotANumberException();
        }
        return v+1;
    }

    public static void increment(IncrementerSignature incrementer, String value) throws NotANumberException {
        System.out.println(incrementer.apply(value));
    }

    public static void main(String[] args) {
        try {
            increment(PassingMethodsThatThrowExceptions::addOne, "10");
        } catch (NotANumberException e) {
            e.printStackTrace();
        }
    }
}

Blogging with Markdown in Blogger

• Use makrdown aware static blog generator such as Jekyll or something based on it like Octopress
• Use a blogging solution based on markdown such as svbtle
• Use a tool that'll either enable markdown support in blogger (see this post) or can post to blogger (like StackEdit)

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