Validators are added to individual input mappings in a query. Input validation allows data services to validate the input parameters in a request and stop the execution of the request if the input doesn’t meet the required criteria. The ESB profile of WSO2 EI provides a set of built-in validators for some of the most common use cases. It also provides an extension mechanism to write custom validators.
Long Range validator
Validates if an integer value is in the specified range. The validator requires a minimum and a maximum value to set the range. For example,
Double Range validator
Validates if a floating point is in the specified range. The validator requires a minimum and a maximum value to set the range. For example,
Validates the string length of a given parameter against a specified length. For example,
Validates the string value of the parameter against a given regular expression. For example,
Used to add your own validation logic by implementing the interface
org.wso2.carbon.dataservices.core.validation.Validator. The definition of the interface is as follows:
If the validation fails, the validate method in the interface by default throws an exception of type
ValidationException . The parameters of the method are as follows:
- context : Is of type
ValidationContext, which contains information about the full set of parameters passed into the request. When the validation logic depends on other parameters, the validation context can be used to check the names/values of the rest of the parameters.
- name : A string value that represents the name of the parameter to be validated.
- value : Is of type
ParamType, which represents the value of the parameter to be validated. It is either
If you need to provide properties when initializing the custom validator, it is necessary to implement the
interface. This extends the Validator interface as shown below.
The init method initializes the set of properties provided for the custom validator via the management console or the configuration file of the data service. See the examples given below.
- Properties provided via the management console:
- Properties provided via the data service configuration file:
After creating a custom validator class, package it in a JAR file and store it in the server's classpath location for external libraries (which is the
Want to try out a scenario that includes input validators? Take a look at the Validating Input Values in a Data Request tutorial.