在WSO2 MI 1.2.0中验证yyyy-MM-dd格式字符串日期的问题咨询及解决方案寻求

Hey, I get your frustration with the new Date() function letting invalid dates slip through—this is a common issue because JavaScript's Date object automatically "fixes" invalid dates instead of rejecting them. Let's fix this for your WSO2 MI 1.2.0 setup, with a few different approaches to choose from:

1. Fix Your Existing Script Mediator Code #

We'll avoid relying solely on new Date() for validation by manually breaking down the date components and checking each rule explicitly. Here's the revised script:

<script language="js"><![CDATA[
var myDate = mc.getProperty("myDate");
var isMyDateValid = 'false';

if(isValidDate(myDate)) {
    isMyDateValid = 'true';
}

function isValidDate(dateString) {
    var log = mc.getServiceLog();
    log.info("Validating date: " + dateString);
    
    // Step 1: Strict regex to filter out non-numeric characters and wrong format
    var regEx = /^\d{4}-\d{2}-\d{2}$/;
    if(!dateString.match(regEx)) {
        log.info("Invalid format: Must be yyyy-MM-dd");
        return false;
    }
    
    // Split into year, month, day (note: months are 0-based in JS Date)
    var parts = dateString.split('-');
    var year = parseInt(parts[0], 10);
    var month = parseInt(parts[1], 10) - 1;
    var day = parseInt(parts[2], 10);
    
    // Step 2: Validate month range (1-12 translates to 0-11)
    if(month < 0 || month > 11) {
        log.info("Invalid month: " + (month + 1));
        return false;
    }
    
    // Step 3: Validate day count for the given month/year (accounts for leap years)
    // new Date(year, month+1, 0) returns the last day of the target month
    var daysInMonth = new Date(year, month + 1, 0).getDate();
    if(day < 1 || day > daysInMonth) {
        log.info("Invalid day: " + day + " for month " + (month + 1));
        return false;
    }
    
    // Final check: Ensure the parsed date matches the original string (no silent corrections)
    var parsedDate = new Date(year, month, day);
    return parsedDate.toISOString().slice(0,10) === dateString;
}

mc.setProperty("isMyDateValid", isMyDateValid);
]]></script>

Why this works: #

• We first use regex to block invalid formats like 2021-1r-09 or 2020-10-09t
• We manually validate month range to catch 2021-14-03
• We calculate the exact number of days in the target month (including leap year checks) to reject dates like 2021-02-29 or 2021-03-32
• The final check ensures no silent date corrections slip through

2. Use WSO2's Built-in XPath Functions (Simplest Approach) #

WSO2 MI supports XPath 2.0, which has strict date validation via xs:date. This is the most concise solution if you don't need custom logging:

<!-- First, check format with regex, then validate as xs:date -->
<property name="isMyDateValid" 
          expression="if (matches($ctx:myDate, '^\d{4}-\d{2}-\d{2}$') and fn:date($ctx:myDate) instance of xs:date) 
                      then 'true' 
                      else 'false'" 
          scope="default" 
          type="STRING"/>

Why this works: #

• The matches() function filters out invalid formats first
• fn:date($ctx:myDate) will throw an error if the date is invalid (like 2021-02-29), which the instance of xs:date check catches cleanly
• No custom scripting needed—uses WSO2's native capabilities

3. Validate with XSD Schema (For XML Payloads) #

If you're validating a date within an XML payload, use WSO2's Validate Mediator with an XSD that enforces the xs:date type:

Step 1: Define the XSD (store it in the Registry as dateValidationSchema)

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="DatePayload">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="myDate" type="xs:date"/>
            </xs:sequence>
        </xs:complexType>
    </xs:schema>

Step 2: Use the Validate Mediator in your sequence

<validate source="//myDate" schema-key="dateValidationSchema">
    <on-success>
        <property name="isMyDateValid" value="true" scope="default" type="STRING"/>
    </on-success>
    <on-fail>
        <property name="isMyDateValid" value="false" scope="default" type="STRING"/>
        <!-- Optional: Add logging or error handling here -->
    </on-fail>
</validate>

Why this works: #

• The xs:date type in XSD strictly enforces all date rules (leap years, month/day ranges, valid format)
• Perfect for scenarios where you need to validate entire XML structures, not just a single property

内容的提问来源于stack exchange，提问作者koko