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Java - Transer 2 attributes from JSP table to Servlet

I created a table with JSP with an image tag used to select 1 of the items. Now I want to forward two variables f.e. name and lastName.
I know how to forward 1 variable with the servlet Get method like this;
'servlet.do?name='+name But how do I obtain this variable in my Servlet and how can I send two or more attributes?

You can pass N-number of attribute while submit likewise,
'servlet.do?name='+name+'&SecondAttr='+varValue+'&ThirdAttr='+varValue
On Other Hand on Servlet you can get all Requested Parameter likewise,
Servlet.java
into doGet/doPost Method,
String name = request.getParameter("name");
String SecondAttr= request.getParameter("SecondAttr");
String ThirdAttr= request.getParameter("ThirdAttr");
Then After do whatever you want.

How to change url in address bar through java

How can I change the url in the address bar through java code in browser(not through javascript or any front end languages)?
I have the url in the address bar like " http://www.abcde.com/home?abc=def&ghi=jkl " but I need to change that url through java code like " http://www.abcde.com/home ". I'm using jsp's for view.
Can anyone help?

If the URL with the request parameters comes from a page on which you have no control (or if it is a link) you can do the following :
use a servlet on that URL
if it finds request parameters in the query strings, it gets them and store them in session, then redirects to itself with no query string
if there is no query string, get the parameter from session, remove them from the session to avoid to reuse them by mistake and process the query
If the parameters exists in query string, because of a form using GET method, simply change the method to POST to pass the parameters in the request body instead of the query string.

Java Servlet Appending to StringBuffer Unrecognized HTML code

How do I give data from one servlet to the next?

Anything after ? is part of the query string. In a Servlet, each key value pair in the query string becomes a request parameters.
If you have access to the HttpServletRequest, you can access them with HttpServletRequest#getParameter(String). For example
request.getParameter("myId");

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

Get key-value pairs from POST body in Restlets

This may or may not be the dumbest question ever.
I'm using Restlet. When the client (which I do not control) POSTs to the URL, I can call the function:
representation.getText();
Which produces the following example list of key-value pairs in string form:
CallStatus=in-progress&CallerCountry=US&CalledZip=24013&ApiVersion=2008-08-01&CallerCity=ARLINGTON&CalledCity=ROANOKE&CallSegmentGuid=&CalledCountry=US&DialStatus=answered&CallerState=VA&CalledState=VA&CallerZip=22039
How can I access this data as a Map of key-value pairs in Restlet?
ANSWER:
Form newForm = new Form(getRequest().getEntity());

Check out these examples quoted from restlet.org (a Form is like a Map):
Getting values from a web form
The web form is in fact the entity of the POST request sent to the server, thus you have access to it via request.getEntity().
There is a shortcut which allows to have a list of all input fields :
Form form = request.getEntityAsForm();
for (Parameter parameter : form) {
System.out.print("parameter " + parameter.getName());
System.out.println("/" + parameter.getValue());
}
Getting values from a query
The query is a part of the identifier (the URI) of the request resource. Thus, you have access to it via request.getResourceRef().getQuery().
There is a shortcut which allows to have a list of all "key=value" pairs :
Form form = request.getResourceRef().getQueryAsForm();
for (Parameter parameter : form) {
System.out.print("parameter " + parameter.getName());
System.out.println("/" + parameter.getValue());
}