The @javax.ws.rs.FormParam annotation injects the matching HTML form parameters present in the request body into a class field, a resource class bean property (the getter method for accessing the attribute), or a method parameter. The request body carrying the form elements must have the content type specified as application/x-www-form-urlencoded.
Consider the following HTML form that contains the data capture form for a department entity. This form allows the user to enter the department entity details:
<!DOCTYPE html>
<html>
<head>
<title>Create Department</title>
</head>
<body>
<form method="POST" action="/resources/departments">
Department Id:
<input type="text" name="departmentId">
<br>
Department Name:
<input type="text" name="departmentName">
<br>
<input type="submit" value="Add Department" />
</form>
</body>
</html>
Upon clicking on the submit button on the HTML form, the department details that you entered will be posted to the REST URI, /resources/departments. The following code snippet shows the use of the @FormParam annotation for extracting the HTML form fields and copying them to the resource class method parameter:
@Path("departments")
public class DepartmentService {
@POST
//Specifies content type as
//"application/x-www-form-urlencoded"
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public void createDepartment(@FormParam("departmentId") short
departmentId,
@FormParam("departmentName") String departmentName) {
createDepartmentEntity(departmentId, departmentName);
}
}