[FIXED] How to encode '%' in request param

Issue

I want to pass request parameter in spring API as

%3 ST%

I send this request via postman like

%253 ST%

This works as expected. The problem is that I need to pass this from one microservice to another via REST API. Both applications are built on Spring framework. When I construct this url as string as

localhost:port/api/version/search?address=%253ST%25

The other microservice endpoint couldn't decode and throws exception

java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "3 "
    at java.net.URLDecoder.decode(URLDecoder.java:194)
    at io.undertow.util.QueryParameterUtils.decodeParam(QueryParameterUtils.java:134)
    at io.undertow.util.QueryParameterUtils.handleQueryParameter(QueryParameterUtils.java:118)
    at io.undertow.util.QueryParameterUtils.parseQueryString(QueryParameterUtils.java:106)
    at io.undertow.util.QueryParameterUtils.mergeQueryParametersWithNewQueryString(QueryParameterUtils.java:151)
    at io.undertow.servlet.spec.RequestDispatcherImpl.forwardImpl(RequestDispatcherImpl.java:205)
    at io.undertow.servlet.spec.RequestDispatcherImpl.forwardImplSetup(RequestDispatcherImpl.java:150)
    at io.undertow.servlet.spec.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:112)
    at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:213)
    at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:171)
    at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
    at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
    at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:394)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)

I am calling the service as

String searchQuery = "%" + searchAddress + "%";
            String uri = MessageFormat.format(GET_SERVICE_ADDRESSES, URLEncoder.encode(searchQuery, "UTF-8"));
            Response response = rootWebTarget.path(uri).request(MediaType.APPLICATION_JSON_TYPE).header("Authorization", "AUTH_TOKEN").get();

I also tried to use URLEncoder to encode and then send this to API. When I encode that search string it looks like

%253+ST%25
or
%253%20ST%25

Both of these encode don't work.

Please help.

Solution

Send the query parameter using the queryParam method.

If you submit your request using the code below, that should pass without issues.

  Client client = ClientBuilder.newClient();
        WebTarget rootWebTarget = client.target("localhost:port/api/version");
        rootWebTarget
                .queryParam("address", "%253ST%25") 
                .path("/search") 
                .request(MediaType.APPLICATION_JSON_TYPE)
                .get();

Your request will look like this localhost:port/api/version/search?address=%253ST%25

Answered By - Nemanja
Answer Checked By - Candace Johnson (JavaFixing Volunteer)