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How to retrieve an integer URL parameter with JSP? [duplicate]

In JSP how do I get parameters from the URL?
For example I have a URL www.somesite.com/Transaction_List.jsp?accountID=5
I want to get the 5.
Is there a request.getAttribute( "accountID" ) like there is for sessions or something similar?

About the Implicit Objects of the Unified Expression Language, the Java EE 5 Tutorial writes:
Implicit Objects
The JSP expression language defines a set of implicit objects:
pageContext: The context for the JSP page. Provides access to various objects including:
servletContext: The context for the JSP page’s servlet and any web components contained in the same application. See Accessing the Web Context.
session: The session object for the client. See Maintaining Client State.
request: The request triggering the execution of the JSP page. See Getting Information from Requests.
response: The response returned by the JSP page. See Constructing Responses.
In addition, several implicit objects are available that allow easy access to the following objects:
param: Maps a request parameter name to a single value
paramValues: Maps a request parameter name to an array of values
header: Maps a request header name to a single value
headerValues: Maps a request header name to an array of values
cookie: Maps a cookie name to a single cookie
initParam: Maps a context initialization parameter name to a single value
Finally, there are objects that allow access to the various scoped variables described in Using Scope Objects.
pageScope: Maps page-scoped variable names to their values
requestScope: Maps request-scoped variable names to their values
sessionScope: Maps session-scoped variable names to their values
applicationScope: Maps application-scoped variable names to their values
The interesting parts are in bold :)
So, to answer your question, you should be able to access it like this (using EL):
${param.accountID}
Or, using JSP Scriptlets (not recommended):
<%
String accountId = request.getParameter("accountID");
%>

In a GET request, the request parameters are taken from the query string (the data following the question mark on the URL). For example, the URL http://hostname.com?p1=v1&p2=v2 contains two request parameters - - p1 and p2. In a POST request, the request parameters are taken from both query string and the posted data which is encoded in the body of the request.
This example demonstrates how to include the value of a request parameter in the generated output:
Hello <b><%= request.getParameter("name") %></b>!
If the page was accessed with the URL:
http://hostname.com/mywebapp/mypage.jsp?name=John+Smith
the resulting output would be:
Hello <b>John Smith</b>!
If name is not specified on the query string, the output would be:
Hello <b>null</b>!
This example uses the value of a query parameter in a scriptlet:
<%
if (request.getParameter("name") == null) {
out.println("Please enter your name.");
} else {
out.println("Hello <b>"+request. getParameter("name")+"</b>!");
}
%>

Use EL (JSP Expression Language):
${param.accountID}

If I may add a comment here...
<c:out value="${param.accountID}"></c:out>
doesn't work for me (it prints a 0).
Instead, this works:
<c:out value="${param['accountID']}"></c:out>

request.getParameter("accountID") is what you're looking for. This is part of the Java Servlet API. See http://java.sun.com/j2ee/sdk_1.3/techdocs/api/javax/servlet/ServletRequest.html for more information.

String accountID = request.getParameter("accountID");

www.somesite.com/Transaction_List.jsp?accountID=5
For this URL there is a method call request.getParameter in java , if you want a number here cast into int, similarly for string value cast into string. so for your requirement , just copy past below line in page,
int accountId =(int)request.getParameter("accountID");
you can now call this value useing accountId in whole page.
here accountId is name of parameter you can also get more than one parameters using this, but this not work. It will only work with GET method if you hit POST request then their will be an error.
Hope this is helpful.

example you wanted to delete the subject record with its subject_id
#RequestMapping(value="subject_setup/delete/{subjectid}",method = RequestMethod.GET)
public ModelAndView delete(#PathVariable int subjectid) {
subjectsDao.delete(subjectid);
return new ModelAndView("redirect:/subject_setup");
}
and the parameter will be used for input on your query
public int delete(int subjectid) {
String sql = "update tbl_subject set isdeleted= '1' where id = "+subjectid+"";
return template.update(sql);
}

page 1 :
Detail
page 2 :
<% String id = request.getParameter("userid");%>
// now you can using id for sql query of hsql detail product

Best approach to de-serialise encrypted query param in java?

I have to make a http request with encrypted query param from one end to another. Say for an example,
String queryParam = "bookName=WingsOfFire&author=AbdulKalam";
String encryptedQueryParam = encrypt(queryParam, encryptionKey);
The final url would be like
domain_name?encryptedQueryParam
On the other end, I would decrypt the query params and obtain the query String. Like
String decryptParam = decrypt(encryptedQueryParam, decryptKey);
Here I'm manually de-serialising my query params at the other end instead of request.getPameter("value").
Is there any other option to handle it in a better way? Any help would be greatly appreciated :-)

#QueryParam Retrieve Form Parameters

I have query parameters which are being sent from browser in the following format
sort[0][field]:prodId
sort[0][dir]:asc
How can I retrieve the above parameters in server using #QueryParam?
From chrome console
take:5
skip:0
page:1
pageSize:5
sort[0][field]:prodId
sort[0][dir]:asc

#QueryParam should be obtained from a Query String that is appended to the end of the request URL. Something like
http://host:port/app/something?key1=value2&key2=value2
You could then get value1 and value2 with
#QueryParam("key1") String value1,
#QueryParam("key2") String value2
Now in the title of your post, you use the word "Form". If this is form data you are trying to submit, you should consider some things. When putting the form data in the query String, this is usually done with data that is not sensitive, and used mainly for GET request, where the parameter values are used to help filter in getting the resource. If this is sensitive data that should be stored on the server, you generally want to POST the data as form data in the body of the request, as seen in the answer from your previous post
UPDATE
If you don't know the key names, which is required to use #QueryParam, you can obtain the entire query string from an injected UriInfo. Something like
#GET
#Path("/path/to/resource")
public Response getKendo( #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();
}
getQueryParameters() will return all the keys and values in MultivalueMap
Alternatively, if you know the keys, which are shown in the URL you posted in the comment
test.jsp?take=5&skip=0&page=1&pageSize=5&sort%5B0%5D%5Bfield%5D=prodId&sort%5B0%5D%5Bdir%5D=asc
then you cause just use all those key for the QueryParam, i.e.
public Response getKendo(#QueryParam("take") int take,
#QueryParam("skip") int skip,
#QueryParam("page") int page,
#QueryParam("sort[0][field]") String field...) {
}
All this crazy stuff sort%5B0%5D%5Bfield%5D is just how URL are encoded with special character, but JAX-RS will convert back to their rightful form, ie "sort[0][field]"

Path on Client side of RESTful Web Service

Ok so this is the code on the server side i just have question on how is the path gonna be defined on the client's side.
This is the method on the server
#Path("{index}/{product}/{amount}")
#PUT
#Produces("text/plain")
public String editTable (#PathParam("index") Integer index, #PathParam("product") String product, #PathParam("amount") Integer amount)
{...}
Now on the client side
{url = new URL( "http://localhost:8080/OrderService/service/tableservice/"+num+"/"+product+"/"+amount);
.....}
/"+num+"/"+product+"/"+amount);
Is this the correct syntax??
Also can the num and amount be integers while the product a string or am i gonna have a problem with it?

You will have problems if the product name has 'unsafe' URL characters in it. Which will probably be the case. To get around that you could URL encode the name before appending it to the URL.
But I think you should rethink your PATH definition in the first place. A good resource endpoint should uniquely identify it. But in your case you are including an amount field in the URL! Which means depending on who is ordering the product the resource URL is changing:
Customer A orders 2 Furbies:
/OrderService/service/tableservice/9/Furbies/2
Customer B orders 1 Furbie
/OrderService/service/tableservice/9/Furbies/1
But in both cases the customers are trying to order the same thing - a Furbie! This is not RESTful. Instead you should define a unique resource endpoint, then send the additional order information as appended data. So for example:
public class Order {
private Integer productId;
private Integer amount;
}
#PUT
#Path("/{productId}/orders")
#Produces("text/plain")
public String updateOrder(#PathParam("productId"), Order order) { ... }
You will notice I removed the index field as well, you can add that back in if absolutely required. You will notice I also added tacked an orders suffix to the end of the URL. To indicate that you are PUT'ing an updated representation for an order made for a product.

If you are mapping any #QueryParam to Integer, ensure that you are taking care of the following:
From the link on Oracle docs:
If a query parameter exists in the query component of the request URI, then the value will be extracted and parsed as a 32–bit signed integer and assigned to the method parameter. If the value cannot be parsed as a 32–bit signed integer, then an HTTP 400 (Client Error) response is returned.
Just to be safe, have your index and amount as String. Parse them to Integer within your service and handle NumberFormatException instead of HTTP 400.

HttpServletRequest - Get query string parameters, no form data

In HttpServletRequest, getParameterMap returns a Map of all query string parameters and post data parameters.
Is there a way to get a Map of ONLY query string parameters? I'm trying to avoid using getQueryString and parsing out the values.

You can use request.getQueryString(),if the query string is like
username=james&password=pwd
To get name you can do this
request.getParameter("username");

Contrary to what cularis said there can be both in the parameter map.
The best way I see is to proxy the parameterMap and for each parameter retrieval check if queryString contains "&?<parameterName>=".
Note that parameterName needs to be URL encoded before this check can be made, as Qerub pointed out.
That saves you the parsing and still gives you only URL parameters.

The servlet API lacks this feature because it was created in a time when many believed that the query string and the message body was just two different ways of sending parameters, not realizing that the purposes of the parameters are fundamentally different.
The query string parameters ?foo=bar are a part of the URL because they are involved in identifying a resource (which could be a collection of many resources), like "all persons aged 42":
GET /persons?age=42
The message body parameters in POST or PUT are there to express a modification to the target resource(s). Fx setting a value to the attribute "hair":
PUT /persons?age=42
hair=grey
So it is definitely RESTful to use both query parameters and body parameters at the same time, separated so that you can use them for different purposes. The feature is definitely missing in the Java servlet API.

As the other answers state there is no way getting query string parameters using servlet api.
So, I think the best way to get query parameters is parsing the query string yourself. ( It is more complicated iterating over parameters and checking if query string contains the parameter)
I wrote below code to get query string parameters. Using apache StringUtils and ArrayUtils which supports CSV separated query param values as well.
Example: username=james&username=smith&password=pwd1,pwd2 will return
password : [pwd1, pwd2] (length = 2)
username : [james, smith] (length = 2)
public static Map<String, String[]> getQueryParameters(HttpServletRequest request) throws UnsupportedEncodingException {
Map<String, String[]> queryParameters = new HashMap<>();
String queryString = request.getQueryString();
if (StringUtils.isNotEmpty(queryString)) {
queryString = URLDecoder.decode(queryString, StandardCharsets.UTF_8.toString());
String[] parameters = queryString.split("&");
for (String parameter : parameters) {
String[] keyValuePair = parameter.split("=");
String[] values = queryParameters.get(keyValuePair[0]);
//length is one if no value is available.
values = keyValuePair.length == 1 ? ArrayUtils.add(values, "") :
ArrayUtils.addAll(values, keyValuePair[1].split(",")); //handles CSV separated query param values.
queryParameters.put(keyValuePair[0], values);
}
}
return queryParameters;
}

Java 8
return Collections.list(httpServletRequest.getParameterNames())
.stream()
.collect(Collectors.toMap(parameterName -> parameterName, httpServletRequest::getParameterValues));

I am afraid there is no way to get the query string parameters parsed separately from the post parameters. BTW the fact that such API absent may mean that probably you should check your design. Why are you using query string when sending POST? If you really want to send more data into URL use REST-like convention, e.g. instead of sending
http://mycompany.com/myapp/myservlet?first=11&second=22
say:
http://mycompany.com/myapp/myservlet/11/22