java - 如果用户未输入二进制值，我如何抛出异常

Question

我想将输入作为来自用户的二进制值。如果他不输入二进制(例如:3214)，那么我要给出WrongFormatException。但是我无法处理 try-throw-catch 的事情。这是我的 Controller 类。

我稍微努力一下，改成这样。有什么有趣的部分我应该改变吗？顺便说一句，它正在工作。谢谢帮助

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class Controller {

private View theView;
private Model theModel;

public Controller( View theView, Model theModel ){

    this.theView = theView;
    this.theModel = theModel;

    theView.addListener( new MyActionListener());   
}

public class MyActionListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent event) {

        int inputBinary = theView.getInputBinary();

        try {
            if ( checkFormat(inputBinary) )
            {
                int outputDecimal = theModel.convertToDecimal(Integer.toString(inputBinary));
                theView.setOutputDecimal(outputDecimal);
            }                   
            else
            {
                throw new WrongFormatException( "Wrong format");
            }

        } catch ( WrongFormatException e ) {

            theView.setOutputDecimal(0);
            theView.displayErrorMessage( "Wrong Format");
        }

    }
}

public boolean checkFormat ( int input )
{
    // check if it is not in true format
    String stringInput = Integer.toString(input);           
    for ( int i = 0; i < stringInput.length(); i++ )
    {
        if ( stringInput.charAt(i) == '0' || stringInput.charAt(i) == '1' )
        {

        }
        else
        {
            return false;
        }
    }
    return true;
}

// my own exception class
public class WrongFormatException extends Exception
{

    // CONSTRUCTOR

    public WrongFormatException( String message )
    {
        super( message );
    }

}   
}

这里先写代码，忽略这部分。

 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;


public class Controller {

private View theView;
private Model theModel;

public Controller( View theView, Model theModel ){

    this.theView = theView;
    this.theModel = theModel;

    theView.addListener( new MyActionListener());   
}

public class MyActionListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent event) {

        // we got the input
        int inputBinary = theView.getInputBinary();

        // create an exception
        WrongFormatException problem = new WrongFormatException( "Input value is not binary");

        // base value, we assme the input is in true format
        boolean isTrueFormat = true;

        // check if it is not in true format
        String stringBinary = Integer.toString(inputBinary);            
        for ( int i = 0; i < stringBinary.length(); i++ )
        {
            if ( stringBinary.charAt(i) == '0' || stringBinary.charAt(i) == '1' )
            {

            }
            else
            {
                isTrueFormat = false;
                i = stringBinary.length();
            }
        }

        // we do the convertion work here
        int outputDecimal = theModel.convertToDecimal(Integer.toString(inputBinary));

        // and we set output textfield
        theView.setOutputDecimal(outputDecimal);


    }
}

// my own exception class
public class WrongFormatException extends Exception
{

    // CONSTRUCTOR

    public WrongFormatException( String message )
    {
        super( message );
    }

}   
}

Answer 1

如果扩展 java.lang.RuntimeException 而不是 java.lang.Exception，则可以从 else block 中抛出 WrongFormatException 而无需声明 throws 子句