Class ServletRequestDataBinder

All Implemented Interfaces:
PropertyEditorRegistry, TypeConverter
Direct Known Subclasses:

public class ServletRequestDataBinder extends WebDataBinder
Special DataBinder to perform data binding from servlet request parameters to JavaBeans, including support for multipart files.

WARNING: Data binding can lead to security issues by exposing parts of the object graph that are not meant to be accessed or modified by external clients. Therefore the design and use of data binding should be considered carefully with regard to security. For more details, please refer to the dedicated sections on data binding for Spring Web MVC and Spring WebFlux in the reference manual.

See the DataBinder/WebDataBinder superclasses for customization options, which include specifying allowed/required fields, and registering custom property editors.

Can also be used for manual data binding. Simply instantiate a ServletRequestDataBinder for each binding process, and invoke bind with the current ServletRequest as argument:

 MyBean myBean = new MyBean();
 // apply binder to custom target object
 ServletRequestDataBinder binder = new ServletRequestDataBinder(myBean);
 // register custom editors, if desired
 // trigger actual binding of request parameters
 // optionally evaluate binding errors
 Errors errors = binder.getErrors();
Rod Johnson, Juergen Hoeller
See Also:
  • Constructor Details

    • ServletRequestDataBinder

      public ServletRequestDataBinder(@Nullable Object target)
      Create a new ServletRequestDataBinder instance, with default object name.
      target - the target object to bind onto (or null if the binder is just used to convert a plain parameter value)
      See Also:
    • ServletRequestDataBinder

      public ServletRequestDataBinder(@Nullable Object target, String objectName)
      Create a new ServletRequestDataBinder instance.
      target - the target object to bind onto (or null if the binder is just used to convert a plain parameter value)
      objectName - the name of the target object
  • Method Details

    • construct

      public void construct(ServletRequest request)
      Use a default or single data constructor to create the target by binding request parameters, multipart files, or parts to constructor args.

      After the call, use DataBinder.getBindingResult() to check for bind errors. If there are none, the target is set, and bind(ServletRequest) can be called for further initialization via setters.

      request - the request to bind
    • createValueResolver

      Allow subclasses to create the DataBinder.ValueResolver instance to use.
    • shouldConstructArgument

      protected boolean shouldConstructArgument(MethodParameter param)
      Description copied from class: DataBinder
      Whether to instantiate the constructor argument of the given type, matching its own constructor arguments to bind values.

      By default, simple value types, maps, collections, and arrays are excluded from nested constructor binding initialization.

      shouldConstructArgument in class DataBinder
    • bind

      public void bind(ServletRequest request)
      Bind the parameters of the given request to this binder's target, also binding multipart files in case of a multipart request.

      This call can create field errors, representing basic binding errors like a required field (code "required"), or type mismatch between value and bean property (code "typeMismatch").

      Multipart files are bound via their parameter name, just like normal HTTP parameters: i.e. "uploadedFile" to an "uploadedFile" bean property, invoking a "setUploadedFile" setter method.

      The type of the target property for a multipart file can be MultipartFile, byte[], or String. Servlet Part binding is also supported when the request has not been parsed to MultipartRequest via MultipartResolver.

      request - the request with parameters to bind (can be multipart)
      See Also:
    • addBindValues

      protected void addBindValues(MutablePropertyValues mpvs, ServletRequest request)
      Extension point that subclasses can use to add extra bind values for a request. Invoked before WebDataBinder.doBind(MutablePropertyValues). The default implementation is empty.
      mpvs - the property values that will be used for data binding
      request - the current request
    • closeNoCatch

      public void closeNoCatch() throws ServletRequestBindingException
      Treats errors as fatal.

      Use this method only if it's an error if the input isn't valid. This might be appropriate if all input is from dropdowns, for example.

      ServletRequestBindingException - subclass of ServletException on any binding problem
    • valueResolver

      public static DataBinder.ValueResolver valueResolver(ServletRequest request, WebDataBinder binder)
      Return a ServletRequest DataBinder.ValueResolver. Mainly for use from WebRequestDataBinder.