在Spring中自定义PropertyEditorSupport

Question

I'm working with Spring 3.2. In order to validate double values globally, I use CustomNumberEditor . The validation is indeed performed.

But when I input a number like 1234aaa , 123aa45 and so forth, I expect the NumberFormatException to be thrown but it doesn't. The docs says,

ParseException is caused, if the beginning of the specified string cannot be parsed

Therefore, such values as mentioned above are parsed up to they are represented as numbers and the rest of the string is then omitted.

To avoid this, and to make it throw an exception, when such values are fed, I need to implement my own Property Editor by extending the PropertyEditorSupport class as mentioned in this question .

package numeric.format;

import java.beans.PropertyEditorSupport;

public final class StrictNumericFormat extends PropertyEditorSupport
{
    @Override
    public String getAsText() 
    {
        System.out.println("value = "+this.getValue());
        return ((Number)this.getValue()).toString();
    }

    @Override
    public void setAsText(String text) throws IllegalArgumentException 
    {
        System.out.println("value = "+text);
        super.setValue(Double.parseDouble(text));
    }
}

The editors I have specified inside a method annotated with the @InitBinder annotation are as follows.

package spring.databinder;

import java.text.DateFormat;
import java.text.DecimalFormat;
import java.text.Format;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.beans.propertyeditors.CustomNumberEditor;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.context.request.WebRequest;

@ControllerAdvice
public final class GlobalDataBinder 
{
    @InitBinder
    public void initBinder(WebDataBinder binder, WebRequest request)
    {
        DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
        dateFormat.setLenient(false);
        binder.setIgnoreInvalidFields(true);
        binder.setIgnoreUnknownFields(true);
        //binder.setAllowedFields("startDate");
        binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));

        //The following is the CustomNumberEditor

        NumberFormat numberFormat = NumberFormat.getInstance();
        numberFormat.setGroupingUsed(false);
        binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, numberFormat, false));
    } 
}

Since I'm using Spring 3.2, I can take advantage of @ControllerAdvice

---

Out of curiosity, the overridden methods from the PropertyEditorSupport class in the StrictNumericFormat class are never invoked and the statements that redirect the output to the console as specified inside of those methods ( getAsText() and setAsText() ) don't print anything on the server console.

I have tried all the approaches described in all the answers of that question but none worked for me. What am I missing here? Is this required to configure in some xml file(s)?

Answer 1

Clearly you have nowhere passed the StrictNumericFormat reference. You should register your editor like:

 binder.registerCustomEditor(Double.class, new StrictNumericFormat());

BTW Spring 3.X introduced a new way achieving conversion: Converters