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Passing a very long URL to a HTTPServletRequest

I want to pass a long series of request parameters (over 2000 characters in total) from one .jsp to another (via a URL), and make it seem to the receiving HTTPServletRequest as if it received the request parameters normally.
I cannot simply pass the URL normally as IE11 is truncating the URL at about 2000 characters (see What is the maximum length of a URL in different browsers?) so I need to have some kind of workaround.
It is trivial to save the url in the ClientSession with a key in one .jsp
public String addValue(String aString) {
String key=""+UUID.randomUUID();
mapValues.put(key, aString);
return key;
}
and then retrieve it in the other .jsp
public String getValue(String key) {
return mapValues.get(key);
}
However the other .jsp needs a HTTPServletRequest and not a string
I.e. I need to be able to do
public MyPosition(HttpServletRequest request) {
this.id= (String)request.getParameter("ID");
Is there anyway of doing this by converting the retrieved url to a HTTPServletRequest?
I know that I could rewrite MyPosition to take a string and extract the data from there directly, but I would much rather not touch the very lengthy, legacy code.
If I could do setParameter on the request, then this would be a solution. But such an option is not available (see HttpServletRequest - SetParameter)

The only way to modify an HttpServletRequest is to wrap it.

It sounds like you want to make a standard POST request instead of what sounds like a GET request.

I tried both #dimplex's and #Deadron's solutions, which I think should both work, but didn't manage to implement either in the short time frame I had available.
I ended up replacing the HTTPServletRequest request parameter in the MyPosition function with String urlKey and adding the following line inside the function
RequestStr request=new RequestStr(cSession,urlKey);
now my existing code did not need to be changed at all, and request.getParameter("paramName") would call my function below.
public class RequestStr {
String url = "";
public RequestStr(ClientSession cSession, String urlKey) {
super();
this.url = cSession.getValue(urlKey);
}
public String getParameter(String aParam) {
int i = url.indexOf("?" + aParam + "=");
if (i == -1) {
i = url.indexOf("&" + aParam + "=");
}
if (i == -1) {
return null;
} else {
int j = url.indexOf("&", i + 1);
if (j == -1) {
return url.substring(i + aParam.length() + 2);
} else {
return url.substring(i + aParam.length() + 2, j);
}
}
}
}
So all I needed to do was to save the very long URL in the session in a map with key urlKey and then in the request just passed this urlKey, and then I could retrieve the long URL via the urlKey and then decode it via my RequestStr class

How to convert a JSON String to a JSON Object (Gson) in Java?

I am consuming an external API to which the response body is a String in JSON format. I am using Gson to parse the String into a JSON Object. However, I get the following error when trying to display the object in browser.
SyntaxError: JSON.parse: unexpected character at line 1 column 1 of
the JSON data
Here is my code:
Controller
#RequestMapping("/player")
public JsonArray displayPlayer() throws Exception{
String player = "PacSnackz";
smite.createSession();
String test = smite.getPlayer(player);
JsonArray playerObj = new JsonParser().parse(test).getAsJsonArray();
return playerObj;
}
Smite Class
public String getPlayer(String player) throws Exception {
if (!isSessionValid() && !createSession()) return "session null";
return getURL(combine(new String[] {
baseURL + "getplayer" + responseFormat,
devID,
getSignature("getplayer"),
sessionID,
getTimestamp(),
player
}, "/"));
}
This is what the JSON String looks like:
JSON String
[{"Avatar_URL":"","Created_Datetime":"8\/16\/2016 4:30:14 AM","Id":9993055,"Last_Login_Datetime":"4\/23\/2018 8:47:56 PM","Leaves":3,"Level":17,"Losses":19,"MasteryLevel":1,"Name":"PacSnackz","Personal_Status_Message":"","Rank_Stat_Conquest":0,"Rank_Stat_Duel":0,"Rank_Stat_Joust":0,"RankedConquest":{"Leaves":0,"Losses":0,"Name":"League","Points":0,"PrevRank":0,"Rank":0,"Rank_Stat_Conquest":null,"Rank_Stat_Duel":null,"Rank_Stat_Joust":null,"Season":0,"Tier":0,"Trend":0,"Wins":0,"player_id":null,"ret_msg":null},"RankedDuel":{"Leaves":0,"Losses":0,"Name":"Duel","Points":0,"PrevRank":0,"Rank":0,"Rank_Stat_Conquest":null,"Rank_Stat_Duel":null,"Rank_Stat_Joust":null,"Season":0,"Tier":0,"Trend":0,"Wins":0,"player_id":null,"ret_msg":null},"RankedJoust":{"Leaves":0,"Losses":0,"Name":"Joust","Points":0,"PrevRank":0,"Rank":0,"Rank_Stat_Conquest":null,"Rank_Stat_Duel":null,"Rank_Stat_Joust":null,"Season":0,"Tier":0,"Trend":0,"Wins":0,"player_id":null,"ret_msg":null},"Region":"North America","TeamId":0,"Team_Name":"","Tier_Conquest":0,"Tier_Duel":0,"Tier_Joust":0,"Total_Achievements":28,"Total_Worshippers":510,"Wins":35,"ret_msg":null}]
I am using Spring Boot Java and Google's Gson library. I have looked into Jackson as well with no luck either.

I figured out the answer. The trick was to set Player to an array. For other objects I had I used a for loop to return multiple objects. For this example it is set to 0 since there is only one player.
#RequestMapping("/player")
public Player displayPlayer() throws Exception{
String player = "PacSnackz";
smite.createSession();
String test = smite.getPlayer(player);
Gson gson = new Gson();
Player[] playerObj = gson.fromJson(test, Player[].class);
return playerObj[0];
}

Compare JSON response using JUnit and JSONassert

I'm relatively new to Java and I'm asking to write test of JSON response server.
I found JSONassert very useful but I didn't succeed to write the method getRESTData.
Anybody can help please?
#Test
public void testGetFriends() throws JSONException {
JSONObject data = getRESTData("/friends/367.json");
String expected = "{friends:[{id:123,name:\"Corby Page\"}"
+ ",{id:456,name:\"Solomon Duskis\"}]}";
JSONAssert.assertEquals(expected, data, false);
}

You can get the data as String and pass it into JSONAssert.assertEquals.
Converting to JSONObject isn't necessary.
To fetch data from an URL, you can use URL.getContent method:
final String data = new URL("...").getContent();
String expected = "{friends:[{id:123,name:\"Corby Page\"}"
+ ",{id:456,name:\"Solomon Duskis\"}]}";
JSONAssert.assertEquals(expected, data, false);

This can also be achieved with ModelAssert - https://github.com/webcompere/model-assert , which can take anything serializable to JSON as an input:
#Test
public void testGetFriends() throws JSONException {
JSONObject data = getRESTData("/friends/367.json");
String expected = "{friends:[{id:123,name:\"Corby Page\"}"
+ ",{id:456,name:\"Solomon Duskis\"}]}";
assertJson(data).isEqualTo(expected);
}
IIRC JSONObject is essentially a Map, so assertJson will convert it to the internal JsonNode format it uses for comparison.

Store #PathParam values from REST call in a list or array

My function looks like this:
#PUT
#Path("property/{uuid}/{key}/{value}")
#Produces("application/xml")
public Map<String,ValueEntity> updateProperty(#Context HttpServletRequest request,
#PathParam("key") String key,
#PathParam("value") String value,
#PathParam("uuid") String uuid) throws Exception {
...
}
I have to modify it, so it accepts indefinite(or many) list of key-value pairs from REST call, something like
#Path("property/{uuid}/{key1}/{value1}/{key2}/{value2}/{key3}/{value3}/...")
Is it possible to store them in an array or list, so I do not list dozens of #PathParams and parameters, to avoid this:
#PathParam("key1") String key1,
#PathParam("key2") String key2,
#PathParam("key3") String key3,

Might be a good opportunity to rethink this design. By using /s, we are in a way signifying, with each / that we are trying to locate a different resource. Key/Value pairs (in the context of the URL) are mainly for query parameters or matrix parameters.
If /property/{uuid} is the path to a main resource, and we just want to offer some parameters to the client for accessing this resource, then we could allow matrix parameters or query parameters
Matrix Parameters (in a request url) will look something like
/12345;key1=value1;key2=value2;key3=value3
A resource method to obtain the values might look something like
#GET
#Path("/property/{uuid}")
public Response getMatrix(#PathParam("uuid") PathSegment pathSegment) {
StringBuilder builder = new StringBuilder();
// Get the {uuid} value
System.out.println("Path: " + pathSegment.getPath());
MultivaluedMap matrix = pathSegment.getMatrixParameters();
for (Object key : matrix.keySet()) {
builder.append(key).append(":")
.append(matrix.getFirst(key)).append("\n");
}
return Response.ok(builder.toString()).build();
}
See PathSegment
Query Parameters (in a request url) might look something like
/12345?key1=value1&key2=value2&key3=value3
A resource method to obtain the values might look something like
#GET
#Path("/property/{uuid}")
public Response getQuery(#PathParam("uuid") String uuid,
#Context UriInfo uriInfo) {
MultivaluedMap params = uriInfo.getQueryParameters();
StringBuilder builder = new StringBuilder();
for (Object key : params.keySet()) {
builder.append(key).append(":")
.append(params.getFirst(key)).append("\n");
}
return Response.ok(builder.toString()).build();
}
See UriInfo
The difference is that Matrix parameters can be embedded into path segments, while query parameters must be placed at the end of the URL. You can also notice a little difference in syntax.
Some Resources
Query String (Wikipedia)
When to use query parameters versus matrix parameters?
URL matrix parameters vs. request parameters
UPDATE
Also looking at the PUT in you method signature, it appears you are trying update a resource using the path as the values for which you are trying to update, as I don't see any parameters in your method for an entity body. When PUTting, you should be sending the representation in the the entity body, not as as path segments or parameters.

A workaround:
#Path("/foo/bar/{other: .*}
public Response foo(#PathParam("other") VariableStrings vstrings) {
String[] splitPath = vstrings.getSplitPath();
}
VariableStrings class:
public class VariableStrings {
private String[] splitPath;
public VariableStrings(String unparsedPath) {
splitPath = unparsedPath.split("/");
}
}
Path segment sequence to vararg array in JAX-RS / Jersey?
Another example where you map the optional parameter to a Map:
#GET
# Produces({"application/xml", "application/json", "plain/text"})
# Path("/location/{locationId}{path:.*}")
public Response getLocation(#PathParam("locationId") int locationId, #PathParam("path") String path) {
Map < String, String > params = parsePath(path);
String format = params.get("format");
if ("xml".equals(format)) {
String xml = "<location<</location<<id<</id<" + locationId + "";
return Response.status(200).type("application/xml").entity(xml).build();
} else if ("json".equals(format)) {
String json = "{ 'location' : { 'id' : '" + locationId + "' } }";
return Response.status(200).type("application/json").entity(json).build();
} else {
String text = "Location: id=" + locationId;
return Response.status(200).type("text/plain").entity(text).build();
}
}
private Map < String, String > parsePath(String path) {
if (path.startsWith("/")) {
path = path.substring(1);
}
String[] pathParts = path.split("/");
Map < String, String > pathMap = new HashMap < String, String > ();
for (int i = 0; i < pathParts.length / 2; i++) {
String key = pathParts[2 * i];
String value = pathParts[2 * i + 1];
pathMap.put(key, value);
}
return pathMap;
}

Java - Parsing JSON Response - Content is either String or JSONObject

I am facing a typical scenario while parsing JSON Response for one of the Service calls.
The content for one of the attributes (from below example, consider "name" as a attribute) coming as either String or JSONObject.
How to handle these kind of scenarios through code. Also, please consider that json content need not be consistent with same set of attributes.
Example:
String Response
{"name":"Adam"}
JSON Response
{"name":{"FirstName":"Adam", "MiddleName":"Don"} }
OR
{"name":{"FirstName":"Adam", "LastName":"Don"} }
OR
{"name":{"MiddleName":"Adam", "LastName":"Don"} }

You can ask the root JSONObject with the method optJSONObject(name) to return a JSONObject for the given name if it exists and is an JsonObject. Otherwise you can also test with optString(name) for a String.
So something like:
JSONObject root = new JSONObject(... data from server ... );
JSONObject obj = root.optJSONObject("name");
if (obj != null) {
// Do something with the object
} else {
String name = root.getString("name");
// Do something with the string
}

Parse your response JSON as a JSONObject, then get another JSONObject for the "name" key, if it throws a JSONException then your object is probably a String in with case you can call get String for the "name" key in your catch block.
String name = "";
JSONObject serverJSON = new JSONObject(YOUR_JSON_RESPONSE_STRING_FROM_SERVER);
try {
JSONObject nameObject = serverJSON.getJSONObject("name");
if (nameObject.has("first_name")) {
name = nameObject.getString("first_name") + " ";
}
if (nameObject.has("middle_name")) {
name += nameObject.getString("middle_name") + " ";
}
if (nameObject.has("last_name")) {
name += nameObject.getString("last_name");
}
name = name.trim();
} catch (JSONException e) {
// Probably a String, try again...
try {
name = serverJSON.getString("name");
catch (JSONException e) {
// Not a String or a JSONObject... figure out what's wrong...
e.printStackTrace();
}
}
I would really recommend though, that if you have any control of the server that you make sure that the name key choose one type and sticks to it; a JSONObject... You would be able to use the has(String key) member function in if statements to properly find all of your data without knowing what existed at runtime...
EDIT: Thought of a different idea... Parse the String to the first colon and see if the next non-whitespace character is a quotation mark, if it is, then your key belongs to a String, if it is a curly brace then it's a JSONObject. (If neither, then you have an error, because you aren't expecting an array or number or null or anything else...)
boolean jsonIsString = true;
String searchString = json.substring(json.indexOf(":")).trim();
if ("{".equals(searchString.charAt(0)) {
jsonIsString = false;
}

Tonity's solution is good. You can also use this solution.
In my solution, there will be no any Exception fired until JSON is wrong. What I am doing is following.
Search for number of ":" in string.
If it returns 1, then we sure that there is "name" value.
Otherwise, we need to check, whether there is "FirstName","MiddleName" or "LastName" exist in string or not.
Just go through this snippet and you will find solution for your problem.
// String str = "{\"name\":\"chintan\"}";
String str = "{\"name\":{\"FirstName\":\"Chintan\",\"LastName\":\"Rathod\"}}";
try {
//we will check how many ":" are there in string, if it is one, then
// we are going to get "name" field.
if ((str.split(":").length - 1) == 1)
{
Log.d("Home", "1");
JSONObject json = new JSONObject(str);
Log.d("Home", "Name : " + json.get("name"));
}
else
{
Log.d("Home", "more then 2");
JSONObject jName = new JSONObject(str);
JSONObject jTemp = jName.getJSONObject("name");
if (jTemp.toString().contains("FirstName"))
Log.d("Home", "FirstName :" + jTemp.getString("FirstName"));
if (jTemp.toString().contains("MiddleName"))
Log.d("Home","MiddleName :" +jTemp.getString("MiddleName"));
if (jTemp.toString().contains("LastName"))
Log.d("Home", "LastName :" + jTemp.getString("LastName"));
}
} catch (JSONException e) {
e.printStackTrace();
}
Output
08-06 11:52:34.060: D/Home(1439): more then 2
08-06 11:52:34.060: D/Home(1439): FirstName :Chintan
08-06 11:52:34.070: D/Home(1439): LastName :Rathod

I faced a problem like this as well. I didn't want to parse the JSON manually. Do this if firstName exists otherwise do that. I didn't want to mess up my structure because I only define java object and my client handles the parsing. So, I came up with following:
#Getter
#Setter
#ToString
class Response {
private Name name;
#Getter
#Setter
#NoArgsConstructor
#ToString
public static class Name {
private String name;
private String firstName;
private String middleName;
private String lastName;
public Name(String name) {
this.name = name;
}
}
}
Then, parse the json;
ObjectMapper objectMapper = new ObjectMapper();
Response response = objectMapper.readValue(json, Response.class);
Now, string response and JSON response can be parsed with the same class.