Struts2：如何停用FieldValidators的默认消息

Question

I'm working on JAVA EE project using Struts2, which i have a jsp file with to fields name & age:

<s:form action="login" method="post">
      <s:textfield name="name" label="Name" size="20" />
      <s:textfield name="age" label="Age" size="20" />
      <s:submit label="Submit" align="center" />
   </s:form>

And there apropriat Action With annotation validators:

public class LoginAction extends ActionSupport {
    private String name;
    private int age;

    @Override
    public String execute() throws Exception {
        return SUCCESS;
    }

    @RequiredStringValidator(message = "String is empty", shortCircuit=true)
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @ConversionErrorFieldValidator(message = "Please enter a valid age", shortCircuit = true)
    @IntRangeFieldValidator(message = "Age must be in between 28 and 65",min = "29", max = "65",shortCircuit=true)
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

Everything works fine, but when i enter a not valid age (a string for example "test") i get to messages, the one i set in the annotation "Please enter a valid age" and an other one by default "Invalid field value for field "age"" , so my question is how can i desactive it the second message.

Edit: This picture shows the messages i get.

Thank you.

Answer 1

Firs read how the workflow about conversion and validation errors works ;

Then read Type Conversion Error Handling from the official documentation (bolds are mine):

Type conversion error handling provides a simple way to distinguish between an input validation problem and an input type conversion problem.

Any error that occurs during type conversion may or may not wish to be reported. For example, reporting that the input "abc" could not be converted to a number might be important. On the other hand, reporting that an empty string, "", cannot be converted to a number might not be important - especially in a web environment where it is hard to distinguish between a user not entering a value vs. entering a blank value.

By default, all conversion errors are reported using the generic i18n key xwork.default.invalid.fieldvalue , which you can override (the default text is Invalid field value for field "xxx", where xxx is the field name) in your global i18n resource bundle.

However, sometimes you may wish to override this message on a per-field basis. You can do this by adding an i18n key associated with just your action (Action.properties) using the pattern invalid.fieldvalue.xxx , where xxx is the field name.

It is important to know that none of these errors are actually reported directly. Rather, they are added to a map called conversionErrors in the ActionContext. There are several ways this map can then be accessed and the errors can be reported accordingly.

There are two ways the error reporting can occur:

• Globally, using the Conversion Error Interceptor
• On a per-field basis, using the conversion validator

By default, the conversion interceptor is included in struts-default.xml in the default stack. To keep conversion errors from reporting globally, change the interceptor stack, and add additional validation rules.

Then what is happening in your case ?

You are using a default stack (or a custom stack with the same behaviour), that is running the ConversionErrors Interceptor before the Validation Interceptor.

Then, since you are defining a ConversionErrorFieldValidator , you are using both the mechanisms, while you should use only one of them.

You can go with any of the three following way:

Global resource way

• remove your ConversionErrorFieldValidator ;

• create a global i18n resource bundle and add the key

   xwork.default.invalid.fieldvalue = Please enter a valid "{0}" 

Local resource way

• remove your ConversionErrorFieldValidator ;

• create an action resource bundle (for each action / field with this need) and add

   invalid.fieldvalue.age = Please enter a valid age 

Custom way

• remove the ConversionError Interceptor from your stack, for all the actions with this need.

With the first two solutions, you can't shortcircuit it, then you will have both the conversion AND the (first, if short-circuit) validator error. But the values will be preserved and repopulated automatically (eg. inserting abc into an int field, will repopulate abc in the page).

With the last solution, your message will be shortcircuited, but you will have to handle manually the repopulation of the fields, AND you will need to remember to use a custom @ConversionErrorFieldValidator for every field, because unless the conversion error messages will be swallowed.

Personally, I would go with solution 1. It is the safest, and it costs basically zero work.