I'm writing a Rest Service (HTTP Get endpoint), where in the below uri does the following
http://localhost:8080/customers/{customer_id}
fetch the details for the customer_id passed in the uri
if the customer_id is not passed (http://localhost:8080/customers), fetch all the customers details.
Code:
#RequestMapping(method = RequestMethod.GET, value = "customers/{customer_id}")
public List<Customer> getCustomers(
#PathVariable(name = "customer_id", required = false) final String customerId) {
LOGGER.debug("customer_id {} received for getCustomers request", customerId);
}
However, with the above code, for the second scenario control is flowing to getCustomers().
Note: I'm using Java8 and spring-web 4.3.10 version
Highly appreciate any help on this.
Optional #PathVariable is used only if you want to map both GET /customers/{customer_id} and GET customers into single java method.
You cannot send request which will be sent to GET /customers/{customer_id} if you don't send customer_id.
So in your case it will be:
#RequestMapping(method = RequestMethod.GET, value = {"/customers", "customers/{customer_id}"})
public List<Customer> getCustomers(#PathVariable(name = "customer_id", required = false) final String customerId) {
LOGGER.debug("customer_id {} received for getCustomers request", customerId);
}
public abstract boolean required
Whether the path variable is required.
Defaults to true, leading to an exception being thrown if the path variable is missing in the incoming request. Switch this to false if you prefer a null or Java 8 java.util.Optional in this case. e.g. on a ModelAttribute method which serves for different requests.
You can use null or Optional from java8
This may help someone that is trying to use multiple optional path variables.
If you have more than one variable, you can always accept multiple paths.
For instance:
#GetMapping(value = {"customers/{customerId}&{startDate}&{endDate}",
"customers/{customerId}&{startDate}&",
"customers/{customerId}&&{endDate}",
"customers/{customerId}&&"
})
public Customer getCustomerUsingFilter(#PathVariable String customerId, #PathVariable Optional<Date> startDate, #PathVariable Optional<Date> endDate)
Then you would call this URL using all the path separators (in this case &)
Like GET /customers/1&& or
GET /customers/1&&2018-10-31T12:00:00.000+0000 or
GET /customers/1&2018-10-31T12:00:00.000+0000& or
GET /customers/1&2018-10-31T12:00:00.000+0000&2018-10-31T12:00:00.000+0000
You should create two end-point here to handle the individual request :
#GetMapping("/customers")
public List<Customer> getCustomers() {
LOGGER.debug("Fetching all customer");
}
#GetMapping("/customers/{id}")
public List<Customer> getCustomers(#PathVariable("id") String id) {
LOGGER.debug("Fetching customer by Id {} ",id);
}
#GetMapping is equivalent to #RequestMapping(method = RequestMethod.GET) and #GetMapping("/customers/{id}") is equivalent to #RequestMapping(method = RequestMethod.GET, value = "customers/{id}")
Better approach would be like this :
#RestController
#RequestMapping("/customers")
public class CustomerController {
#GetMapping
public List<Customer> getAllCustomers() {
LOGGER.debug("Fetching all customer");
}
#GetMapping("/{id}")
public Customer getCustomerById(#PathVariable("id") String id) {
LOGGER.debug("Fetching customer by Id {} ",id);
}
Related
Using the Web API in .net 5 and conforming an api in rest gives me some challenges about how much to split up the methods in different controllers and the naming conventions.
I have read that if I have users in my system and doing a rest architecture, my controller would be named UserController and method for getting a user would be:
[HttpGet("{id}")]
public string Get(int id)
{
return "value";
}
For getting a list of users it would be:
[HttpGet]
public IEnumerable<string> Get()
{
return new string[] { "value1", "value2" };
}
Updating would be:
[HttpPut("{id}")]
public void Put(int id, [FromBody] string value)
{
}
Delete would have a [HttpDelete], and so on. But what about the special cases?
What if I wanted GetUserByUsername? Would it then be in the same UserController and just be the following, or would it break the REST pattern?:
[HttpGet("{username}")]
public Task GetByUsername(string username)
{
}
What if I needed a call to the api get some data to populate the "createuser page", lets say I need the roles that the user could be created as and some other information and would like to do it in one call. Could I then just create a "InitCreateUser" in the UserController and not break the REST pattern?
[HttpPost]
public Task InitCreateUser()
{
}
What if I needed Login and Logout methods, would it be AutenticationController and just have the two methods: (It's just so far from the other pattern when its not called just Get() Post() and so on)
[HttpPost]
public Task Login(LoginRequest request)
{
}
[HttpPost]
public Task Logout(LogoutRequest request)
{
}
Yes you would put it in the same controller as it is still dealing with the user, and it is good habit to keep functions involving a specific entity in the same location.
But that obviously has the issue of having different endpoints such as Id and Username. A simple way to do this is to indicate which you want to use:
[HttpGet("Id/{id}")]
public string Get([FromRoute] int id) {...}
-> api/User/Id/293
[HttpGet("Username/{username}")]
public string Get([FromRoute] string username) {...}
-> api/User/Username/Tom
Another way is to have a base request and have other functions be offshoots of it
[HttpGet("{id}")]
public string Get([FromRoute] int id) {...}
-> api/User/293
[HttpGet("Username/{username}")]
public string Get([FromRoute] string username) {...}
-> api/User/Username/Tom
[HttpGet("Customer/{custNo}")]
public string Get([FromRoute] string custNo) {...}
-> api/User/Customer/5DtU22D
But lets say you have the Id of the user and you wish to do other functions like get relevant data from the user to display, but not all of it. Or You want to check all the relating data towards a specific funciton,
then you can do something like this:
[HttpGet("{id}/Permissions")]
public PermissionModel GetUserPermission([FromRoute] int id) {...}
[HttpPut("{id}/Permissions")]
public bool UpdateUserPermission([FromRoute] int id, [FromBody] PermissionModel permission) {...}
Or even further derived functionalities
[HttpGet("{id}/Account")]
public string GetUserAccount([FromRoute] int id) {...}
[HttpGet("{id}/Account/Funds")]
public double GetUserAccountTotal([FromRoute] int id) {...}
if you are accessing list properties, for example the user has many accounts for example, you can add a secondary key:
[HttpGet("{id}/Accounts")]
public IEnumerable<string> GetUserAccount([FromRoute] int id) {...}
[HttpGet("{id}/Accounts/{accountId}/Funds")]
public double GetUserAccountTotal([FromRoute] int id, [FromRoute] int accountId) {...}
#GetMapping("/getAccount")
public Account validateAccount(#RequestBody) {
}
Very new to spring boot. My account file has 5+ values all strings, username, password, id, and some etc things.
Given this
{
"username": "bob"
"password": "password"
}
It should give this with 200 response code OK
{
"id": "45645646546"
"username": "bob"
"password": "password"
"status": "Single"
"filler": "filler"
}
However I'm not sure how to read the "username" and "password" json in my validateAccount function
Not really related to this question but does anyone know how to send a response code in the function? Like .sendresponseheader(400) something like that
public class AccountDTO {
#JsonIgnore
private Long id;
#NotNull
private String username;
#NotNull
private String password;
#JsonIgnore
private String status;
#JsonIgnore
private String filler;
// getters & setters
}
You may want to create a DTO (Data Transaction Object) as shown above. Here's a link to it's wiki.
Next pass map user input into this DTO using #RequestBody annotation.
#RestController
public class AccountController {
#GetMapping("/accounts")
public ResponseEntity<Account> validateAccount(#RequestBody AccountDTO accountDTO) {
return new ResponseEntity<>(accountService.validate(accountDTO), HttpStatus.OK);
}
}
Or you can use
#RestController
public class AccountController {
#GetMapping("/accounts")
public Response validateAccount(#RequestBody AccountDTO accountDTO) {
return new ResponseEntity().ok(accountService.validate(accountDTO));
}
}
The user input will be converted from json to AccountDTO using whatever JSON processor your're using most probably it'll be com.fasterxml.jackson.core.
The #JsonIgnore and #NotNull annotation will ensure only username and password fields are used and others are ignored while taking input from user.
You can pass this DTO to your service classes and use something like findByUsername() in your Business Logic and return populated AccountDTO using the below mapper function or some external libraries like Model Mapper or MapStruct.
public toAccountDTO(Account account) {
AccountDTO accountDTO = new AccountDTO();
accountDTO.setUsername(account.getUsername());
// and so on...
return accountDTO;
}
And for your last query, wrap the returned AccountDTO object in ResponseEntity wrapper to provide a proper Response Code with your payload. Here's a link to ResponseEntity Java docs.
AccountDto.java
===============
class AccountDto{
private Long id;
private String username;
private String password;
private String status;
private String filler;
//getters & setters
}
#GetMapping("/getAccount")
public ResponseEntity validateAccount(#RequestBody AccountDto accountDto) {
return new ResponseEntity<>(accountServie.validate(accountDto),HttpStatus.OK);
}
You can do your custom operations before returning the response. Take a look Best Practice of REST
For json response nothing specific just mark class with #RestController.
For #RequestBody just use a pojo to bind the values
For error code and status you can use ResponseEntity
I have this method:
#GetMapping(value = "warehouses/{warehouseId}/issues", headers = BOOTGRID_REQUEST)
public ResponseEntity<BootgridResponse<T>> listWarehouseIssues(
#PathVariable final long warehouseId,
#RequestParam(required = false, defaultValue = ISSUE_STATE_ALL) final String state,
#Valid #ModelAttribute final BootgridRequest request,
final BindingResult bindingResult
)
Worked great in all cases until I registered a new filter that wraps the request into a wrapper.
#Bean
public FilterRegistrationBean someFilterRegistration() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(crossScriptingFilter());
registration.addUrlPatterns("/*");
registration.setName("XFilter");
registration.setOrder(1);
return registration;
}
#Bean
public Filter crossScriptingFilter() {
return new CrossScriptingFilter();
}
Since, the argument "state" is given null when not specified in the request params.
When I remove the filter registration, I get the default value instead of null.
I am missing a piece here, I don't get why the default value wouldn't be given ?
I think that the "value" property is missing. This value represent the name of the request param:
#RequestParam(value = "state", required = false, defaultValue = ISSUE_STATE_ALL) final String state
It seems I had environment issues, other services also had default values but was provided.
After a while, it seems all was back to normal and working again.
This question could also be deleted, since it provides nothing concrete to readers.
Let us take the following JSON response which I want to return from my REST service,
{
"id" : 123,
"name" : "ABC",
}
For the above JSON response, I can create a POJO class like,
public class Student{
private long id;
private String name;
//getters and setters
}
So, I can write a GET service to return the Student object which will be then transformed as JSON.
#GET
#Produces(MediaType.APPLICATION_JSON)
public Response get(){
Student student = new Student();
student.setId(123);
student.setName("ABC");
return Response.ok(student).build();
}
It works fine. Now I want to introduce optional parameters to my JSON response as follows,
{
"id" : 123,
"name" : "ABC",
"params" : {"param1":"xxx","param2":342}
}
Here the params in the JSON response is an Object type and the attributes of that object are not fixed. It will vary for every request like sometime it can have 3 attributes and sometime it will have none. I don't know how to create my POJO class for this requirement. Can anybody suggest me a way how to do it?
Unless you don't need anything special, you should design it as like:
public class Student{
private long id;
private String name;
//getters and setters
private Map<String, String> parameters = new HashMap<>();
public void add(String key, String value) {
parameters.put(key, value);
}
public void addAll(Map<String, String> map) {
parameters.putAll(map);
}
}
If you need type safety then the design is little bit complicated a consider using something like:
class StudentParameters {
long param1;
String param2;
}
and Student:
public class Student{
private long id;
private String name;
//getters and setters
private StudentParameters studentParameters;
public setStudentParameters(final StudentParameters studentParameters) {
this.studentParameters = studentParameters;
}
}
Do not create complex hierarchies e.g Map<List<List>, List<List>> it will complicate whole structure.
I am trying to make a RESTful application in Java using Spring boot by following the tutorial here. I want to modify it so that I can extract an identifier from the URL and use it to serve requests.
So http://localhost:8080/members/<memberId> should serve me a JSON object with information about the member whose ID is <memberId>. I don't know how to
Map all http://localhost:8080/members/* to a single controller.
Extract the from the URL.
Should the logic of extracting the memberId and using it be part of the controller or a separate class, as per the MVC architecture?
I am new to Spring/Spring-boot/MVC. It is quite confusing to get started with. So please bear with my newbie questions.
Map all http://localhost:8080/members/* to a single controller.
You can use a placeholder in a request mapping to so it'll handle multiple URLs. For example:
#RequestMapping("/members/{id}")
Extract the id from the URL
You can have the value of a placeholder injected into your controller method using the #PathVariable annotation with a value that matches the name of the placeholder, "id" in this case:
#RequestMapping("/members/{id}")
public Member getMember(#PathVariable("id") long id) {
// Look up and return the member with the matching id
}
Should the logic of extracting the memberId and using it be part of the controller or a separate class, as per the MVC architecture?
You should let Spring MVC extract the member id from the URL as shown above. As for using it, you'll probably pass the URL to some sort of repository or service class that offers a findById method.
As you can see in the code below, service for customer are in one controller to get one and to add new customer.
So, you will have 2 services:
http://localhost:8080/customer/
http://localhost:8080/customer/{id}
#RestController("customer")
public class SampleController {
#RequestMapping(value = "/{id}", method = RequestMethod.GET)
public Customer greetings(#PathVariable("id") Long id) {
Customer customer = new Customer();
customer.setName("Eddu");
customer.setLastname("Melendez");
return customer;
}
#RequestMapping(value = "/{id}", method = RequestMethod.POST)
public void add(#RequestBody Customer customer) {
}
class Customer implements Serializable {
private String name;
private String lastname;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
public String getLastname() {
return lastname;
}
}
}