I'm trying to retrieve parameters from a http POST request with Spring MVC.
The request contains the following json object (content-type : application/json), which itself contains an array of customObjects :
{
"globalId":"338",
"lines":[
{
"id": "someId",
"lib":"blabla",
...
}
]
}
Here's the code I'm trying to use :
#RequestMapping(method = RequestMethod.POST, value = "/valider")
#ResponseBody
public void valider(final HttpServletRequest request, #RequestParam("globalId") final String globalId, #RequestParam("lines") final MyCustomObject[] lines) {
All I'm getting is a "bad request" error (http 400).
Is it possible to separately retrieve the two parameters "globalId" and "lines" ? Or since they are in the same json object, it has to be treated has a single parameter ? How do you proceed when you have more than one parameter in a Post request ?
I think you're looking for something like `#RequestBody. Create a class to represent your JSON data. In your case, this class will contain two member variables - globalId as a string and lines as an array of the object it represents. Then in your controller method, you will use the #RequestBody annotation on this class type so that Spring will be able to convert the JSON into object. Check the examples below.
http://www.leveluplunch.com/java/tutorials/014-post-json-to-spring-rest-webservice/
JQuery, Spring MVC #RequestBody and JSON - making it work together
http://www.techzoo.org/spring-framework/spring-mvc-requestbody-json-example.html
create model object to map your Json data
class DLibrary{
int id;
String lib;
//getters/setters
}
class GLibrary{
int globalId;
List<DLibrary> lines;
//getters/setters
}
Replace your controller code with below
#RequestMapping(method = RequestMethod.POST, value = "/valider")
#ResponseBody
public void valider(#RequestBody GLibrary gLibrary) {
#RequestBody annotation will map Json to Java Object implicitly.
To achieve this spring must require jackson-core and jackson-mapper library included in your application and your Java class should have getter and setters i.e it must follow bean standards.
Indeed, I have to use #RequestBody to get the JSON object.
Quick summary, depending on how the parameters are passed in the http POST body request :
one JSON object (Content-Type: application/json), use #RequestBody to map the json object to a java object
multiple parameters (Content-Type: application/x-www-form-urlencoded), use #RequestParam for each parameter
Related
PostMapping method
#RestController
#RequestMapping("/validate")
public class Validatesimapi {
#PostMapping
public Simoffers validateSim(#RequestBody ???)
}
I want to pass following json object through post request and accept it in validateSim. What should I write at ???.
{
"id": "1234",
"num":"2343335"
}
both the datatypes of id and num is String.
enter code here
It’s as simple as adding a DTO with the fields that you want. The Jackson mapper will map the json to that object.
I have come across a problem of parsing json data . I am building project using spring boot based on REST api . When i have to parse data corresponding to domain then it is very easy , i use RequestBody in controller method with domain name but in current scenerio i have a list of domain in json form :
{
"data":[
{
"type":"abc",
"subtypes":[
{
"leftValue":"BEACH",
"rightValue":"MOUNTAIN",
"preferencePoint":60
},
{
"leftValue":"ADVENTURE",
"rightValue":"LEISURE",
"preferencePoint":60
}
]
},
{
"type":"mno",
"subtypes":[
{
"leftValue":"LUXURY",
"rightValue":"FUNCTIONAL",
"preferencePoint":60
},
{
"leftValue":"SENSIBLE",
"rightValue":"AGGRESIVE",
"preferencePoint":0
}
]
}
]
}
I am sending data in list where type is the property of class Type
and class Type has list of Subtypes class and subtype class contains leftValue and rightValue as enums
I am using spring boot which uses jackson liberary by default and i want to parse this data into corresponding Type class using Jackson. Can any one provide me solution.
It wasn't clear to me if you have static or dynamic payload.
Static payload
For static one, I would personally try to simplify your payload structure. But your structure would look like this. (I skipped getters and setters. You can generate them via Lombok library).
public class Subtype{
private String leftValue;
private String rightValue;
private int preferencePoint;
}
public class Type{
private String type;
private List<Subtype> subtypes;
}
public class Data{
private List<Type> data;
}
Then in your controller you inject Data type as #RequestBody.
Dynamic payload
For dynamic payload, there is option to inject LinkedHashMap<String, Object> as #RequestBody. Where value in that map is of type Object, which can be casted into another LinkedHashMap<String, Object> and therefore this approach support also nested objects. This can support infinite nesting this way. The only downside is that you need to cast Objects into correct types based on key from the map.
BTW, with pure Spring or Spring Boot I was always able to avoid explicit call against Jackson API, therefore I don't recommend to go down that path.
I am trying to pass POST data from my jsp with jquery-ajax to my Spring-MVC controller function. The data is passed fine and I can print the JSON data when I use a String object to receive the RequestBody. But when I employ a DTO which has a List variable declared with its own objects the controller returns a '415 Unsupported Media Type Error' with the following statement,
The server refused this request because the request entity is in a format not supported by the requested resource for the requested method.
below given is the DTO class
public class anyClassDTO{
private String name;
private List<anyClassDTO> subList = new ArrayList<anyClassDTO>();
//getters and setters here
}
Now, here is the controller function
#RequestMapping(headers ={"Accept=application/json"}, value = "urlFromJsp", method = RequestMethod.POST)
public #ResponseBody
String addData (HttpServletRequest request,
#RequestBody List<anyClassDTO> dtoObject,
Model model)
{
return "{\"value\":\"true\"}";
}
Is it not possible for a list of objects to be received from the jsp page to a controller via AJAX?
Here is a set of sample data being passed from the jsp
[{"name":"module1","subList":[{"name":"chapter1","subList":[{"name":"subchapter1","subList":null}]}]},{"name":"module2","subList":[{"name":"chapter1","subList":[{"name":"subchapter1","subList":null}]}]}]
Make sure your AJAX request sets the request's Content-Type to application/json.
Spring typically uses a MappingJacksonHttpMessageConverter to convert the request body when you specify #RequestBody. This HttpMessageConverter only supports application/*+json type content types, so you have to make sure your request contains it.
Well, we could make it work as it is by adding a little more detail. Instead of receiving the #ResponseBody as a List object I created another DTO which holds a List object of the original DTO. So the second DTO is basically a dummy which receives the data from AJAX as a single object.
Like I have said in the question I have a DTO as follows
public class AnyClassDTO{
private String name;
private List<anyClassDTO> subList = new ArrayList<anyClassDTO>();
//getters and setters here
}
I created another DTO which holds a List of the above DTO
public class DummyDTO{
private List<AnyClassDTO> dummyObj;
//getters and setters here
}
Then in the controller I changed the function to
#RequestMapping(headers ={"Accept=application/json"}, value = "urlFromJsp", method = RequestMethod.POST)
public #ResponseBody
String addData (HttpServletRequest request,
#RequestBody DummyDTO dummyDTOObj,
Model model)
{
return "{\"value\":\"true\"}";
}
Earlier if I was sending a list directly from AJAX, now I am sending a stringified litteral with a variable which holds the whole data.
And it works like a charm!
In jersey a Java bean can be auto-deserialized from within a request body but what if I want to read a parameter without creating a special type. Is it possible to do this using annotations.
My current code is:
public class RequestData {
String param;
}
...
public Response readData(RequestData data) {
data.getParam();
...
}
I want it to be something like:
public Response readData(#RequestParam("param") String param) {
...
}
If its not already clear the input JSON is:
{
"param":"some value"
}
The type of your input JSON is Map<String, String> so if you want to have undifferentiated input you could use that as your request parameter and read the values that you require.
Note that #RequestParam looks at the request parameters and not the body, so it's a different beast.
You do this by letting Jersey pass you String as is (as per annotations), and then data-bind it using Jackson ObjectMapper (thing Jersey uses internally for JSON binding):
Map<String,Object> map = objectMapper.readValue(param, Map.class);
to get access to ObjectMapper, you can use JAX-RS injection annotation (#Context I think?) in the resource class:
#Context
private ObjectMapper objectMapper;
I've been Googling my butt off trying to find out how to do this: I have a Jersey REST service. The request that invokes the REST service contains a JSON object. My question is, from the Jersey POST method implementation, how can I get access to the JSON that is in the body of the HTTP request?
Any tips, tricks, pointers to sample code would be greatly appreciated.
Thanks...
--Steve
As already suggested, changing the #Consumes Content-Type to text/plain will work, but it doesn't seem right from an REST API point of view.
Imagine your customer having to POST JSON to your API but needing to specify the Content-Type header as text/plain. It's not clean in my opinion. In simple terms, if your API accepts JSON then the request header should specify Content-Type: application/json.
In order to accept JSON but serialize it into a String object rather than a POJO you can implement a custom MessageBodyReader. Doing it this way is just as easy, and you won't have to compromise on your API spec.
It's worth reading the docs for MessageBodyReader so you know exactly how it works. This is how I did it:
Step 1. Implement a custom MessageBodyReader
#Provider
#Consumes("application/json")
public class CustomJsonReader<T> implements MessageBodyReader<T> {
#Override
public boolean isReadable(Class<?> type, Type genericType,
Annotation[] annotations,MediaType mediaType) {
return true;
}
#Override
public T readFrom(Class<T> type, Type genericType, Annotation[] annotations,
MediaType mediaType, MultivaluedMap<String, String> httpHeaders,
InputStream entityStream) throws IOException, WebApplicationException {
/* Copy the input stream to String. Do this however you like.
* Here I use Commons IOUtils.
*/
StringWriter writer = new StringWriter();
IOUtils.copy(entityStream, writer, "UTF-8");
String json = writer.toString();
/* if the input stream is expected to be deserialized into a String,
* then just cast it
*/
if (String.class == genericType)
return type.cast(json);
/* Otherwise, deserialize the JSON into a POJO type.
* You can use whatever JSON library you want, here's
* a simply example using GSON.
*/
return new Gson().fromJson(json, genericType);
}
}
The basic concept above is to check if the input stream is expected to be converted to a String (specified by Type genericType). If so, then simply cast the JSON into the specified type (which will be a String). If the expected type is some sort of POJO, then use a JSON library (e.g. Jackson or GSON) to deserialize it to a POJO.
Step 2. Bind your MessageBodyReader
This depends on what framework you're using. I find that Guice and Jersey work well together. Here's how I bind my MessageBodyReader in Guice:
In my JerseyServletModule I bind the reader like so --
bind(CustomJsonReader.class).in(Scopes.SINGLETON);
The above CustomJsonReader will deserialize JSON payloads into POJOs as well as, if you simply want the raw JSON, String objects.
The benefit of doing it this way is that it will accept Content-Type: application/json. In other words, your request handler can be set to consume JSON, which seems proper:
#POST
#Path("/stuff")
#Consumes("application/json")
public void doStuff(String json) {
/* do stuff with the json string */
return;
}
Jersey supports low-level access to the parsed JSONObject using the Jettison types JSONObject and JSONArray.
<dependency>
<groupId>org.codehaus.jettison</groupId>
<artifactId>jettison</artifactId>
<version>1.3.8</version>
</dependency>
For example:
{
"A": "a value",
"B": "another value"
}
#POST
#Path("/")
#Consumes(MediaType.APPLICATION_JSON)
public void doStuff(JSONObject json) {
/* extract data values using DOM-like API */
String a = json.optString("A");
Strong b = json.optString("B");
return;
}
See the Jersey documentation for more examples.
I'm not sure how you would get at the JSON string itself, but you can certainly get at the data it contains as follows:
Define a JAXB annotated Java class (C) that has the same structure as the JSON object that is being passed on the request.
e.g. for a JSON message:
{
"A": "a value",
"B": "another value"
}
Use something like:
#XmlAccessorType(XmlAccessType.FIELD)
public class C
{
public String A;
public String B;
}
Then, you can define a method in your resource class with a parameter of type C. When Jersey invokes your method, the JAXB object will be created based on the POSTed JSON object.
#Path("/resource")
public class MyResource
{
#POST
public put(C c)
{
doSomething(c.A);
doSomethingElse(c.B);
}
}
This gives you access to the raw post.
#POST
#Path("/")
#Consumes("text/plain")
#Produces(MediaType.APPLICATION_JSON)
public String processRequset(String pData) {
// do some stuff,
return someJson;
}
Submit/POST the form/HTTP.POST with a parameter with the JSON as the value.
#QueryParam jsonString
public desolveJson(jsonString)
Some of the answers say a service function must use consumes=text/plain but my Jersey version is fine with application/json type. Jackson and Jersey version is
jackson-core=2.6.1, jersey-common=2.21.0.
#POST
#Path("/{name}/update/{code}")
#Consumes({ "application/json;charset=UTF-8" })
#Produces({ "application/json;charset=UTF-8" })
public Response doUpdate(#Context HttpServletRequest req, #PathParam("name") String name,
#PathParam("code") String code, String reqBody) {
System.out.println(reqBody);
StreamingOutput stream = new StreamingOutput() {
#Override public void write(OutputStream os) throws IOException, WebApplicationException {
..my fanzy custom json stream writer..
}
};
CacheControl cc = new CacheControl();
cc.setNoCache(true);
return Response.ok().type("application/json;charset=UTF-8")
.cacheControl(cc).entity(stream).build();
}
Client submits application/json request with a json request body. Servlet code may parse string to JSON object or save as-is to a database.
SIMPLE SOLUTION:
If you just have a simple JSON object coming to the server and you DON'T want to create a new POJO (java class) then just do this.
The JSON I am sending to the server
{
"studentId" : 1
}
The server code:
//just to show you the full name of JsonObject class
import javax.json.JsonObject;
#Path("/")
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public Response deleteStudent(JsonObject json) {
//Get studentId from body <-------- The relevant part
int studentId = json.getInt("studentId");
//Return something if necessery
return Response.ok().build();
}