public static int remotePost()

in core/src/main/java/hudson/Main.java [94:205]
88 lines of code
20 McCabe index (conditional complexity)

    public static int remotePost(String[] args) throws Exception {
        String projectName = args[0];

        String home = getHudsonHome();
        if(!home.endsWith("/"))     home = home + '/';  // make sure it ends with '/'

        // check for authentication info
        String auth = new URL(home).getUserInfo();
        if(auth != null) auth = "Basic " + new Base64Encoder().encode(auth.getBytes(StandardCharsets.UTF_8));

        {// check if the home is set correctly
            HttpURLConnection con = open(new URL(home));
            if (auth != null) con.setRequestProperty("Authorization", auth);
            con.connect();
            if(con.getResponseCode()!=200
            || con.getHeaderField("X-Hudson")==null) {
                System.err.println(home+" is not Hudson ("+con.getResponseMessage()+")");
                return -1;
            }
        }

        URL jobURL = new URL(home + "job/" + Util.encode(projectName).replace("/", "/job/") + "/");

        {// check if the job name is correct
            HttpURLConnection con = open(new URL(jobURL, "acceptBuildResult"));
            if (auth != null) con.setRequestProperty("Authorization", auth);
            con.connect();
            if(con.getResponseCode()!=200) {
                System.err.println(jobURL + " is not a valid external job (" + con.getResponseCode() + " " + con.getResponseMessage() + ")");
                return -1;
            }
        }

        // get a crumb to pass the csrf check
        String crumbField = null, crumbValue = null;
        try {
            HttpURLConnection con = open(new URL(home +
                    "crumbIssuer/api/xml?xpath=concat(//crumbRequestField,\":\",//crumb)'"));
            if (auth != null) con.setRequestProperty("Authorization", auth);
            String line = IOUtils.readFirstLine(con.getInputStream(),"UTF-8");
            String[] components = line.split(":");
            if (components.length == 2) {
                crumbField = components[0];
                crumbValue = components[1];
            }
        } catch (IOException e) {
            // presumably this Hudson doesn't use CSRF protection
        }

        // write the output to a temporary file first.
        File tmpFile = File.createTempFile("jenkins","log");
        try {
            int ret;
            try (OutputStream os = Files.newOutputStream(tmpFile.toPath());
                 Writer w = new OutputStreamWriter(os, StandardCharsets.UTF_8)) {
                w.write("<?xml version='1.1' encoding='UTF-8'?>");
                w.write("<run><log encoding='hexBinary' content-encoding='"+Charset.defaultCharset().name()+"'>");
                w.flush();

                // run the command
                long start = System.currentTimeMillis();

                List<String> cmd = new ArrayList<>(Arrays.asList(args).subList(1, args.length));
                Proc proc = new Proc.LocalProc(cmd.toArray(new String[0]),(String[])null,System.in,
                    new DualOutputStream(System.out,new EncodingStream(os)));

                ret = proc.join();

                w.write("</log><result>"+ret+"</result><duration>"+(System.currentTimeMillis()-start)+"</duration></run>");
            } catch (InvalidPathException e) {
                throw new IOException(e);
            }

            URL location = new URL(jobURL, "postBuildResult");
            while(true) {
                try {
                    // start a remote connection
                    HttpURLConnection con = open(location);
                    if (auth != null) con.setRequestProperty("Authorization", auth);
                    if (crumbField != null && crumbValue != null) {
                        con.setRequestProperty(crumbField, crumbValue);
                    }
                    con.setDoOutput(true);
                    // this tells HttpURLConnection not to buffer the whole thing
                    con.setFixedLengthStreamingMode((int)tmpFile.length());
                    con.connect();
                    // send the data
                    try (InputStream in = Files.newInputStream(tmpFile.toPath())) {
                        org.apache.commons.io.IOUtils.copy(in, con.getOutputStream());
                    } catch (InvalidPathException e) {
                        throw new IOException(e);
                    }

                    if(con.getResponseCode()!=200) {
                        org.apache.commons.io.IOUtils.copy(con.getErrorStream(), System.err);
                    }

                    return ret;
                } catch (HttpRetryException e) {
                    if(e.getLocation()!=null) {
                        // retry with the new location
                        location = new URL(e.getLocation());
                        continue;
                    }
                    // otherwise failed for reasons beyond us.
                    throw e;
                }
            }
        } finally {
            tmpFile.delete();
        }
    }