Initial check-in.

src/main/java/com/messners/gitlab/api/GitLabApiForm.java

+package com.messners.gitlab.api;
+
+import javax.ws.rs.core.Form;
+
+/**
+ * This class extends the standard JAX-RS Form class to make it fluent.
+ */
+public class GitLabApiForm extends Form {
+
+    /**
+     * Fluent method for adding query and form parameters to a get() or post() call.
+     * 
+     * @param formData the Form containing the name/value pairs
+     * @param name the name of the field/attribute to add
+     * @param value the value of the field/attribute to add
+     * @return this GitLabAPiForm instance
+     */
+    protected GitLabApiForm withParam(String name, Object value) throws IllegalArgumentException {
+        return (withParam(name, value, false));
+    }
+
+    /**
+     * Fluent method for adding query and form parameters to a get() or post() call.
+     * If required is true and value is null, will throw an IllegalArgumentException.
+     * 
+     * @param formData the Form containing the name/value pairs
+     * @param name the name of the field/attribute to add
+     * @param value the value of the field/attribute to add
+     * @param required the field is required flag
+     * @return this GitLabAPiForm instance
+     * @throws IllegalArgumentException if a required parameter is null or empty
+     */
+    protected GitLabApiForm withParam(String name, Object value, boolean required) throws IllegalArgumentException {
+
+        if (value == null) {
+
+            if (required) {
+                throw new IllegalArgumentException(name + " cannot be empty or null");
+            }
+
+            return (this);
+        }
+
+        String stringValue = value.toString().trim();
+        if (required && stringValue.length() == 0) {
+            throw new IllegalArgumentException(name + " cannot be empty or null");
+        }
+
+        this.param(name, stringValue);
+        return (this);
+    }
+}

src/main/java/com/messners/gitlab/api/Utils.java

+package com.messners.gitlab.api;
+
+import java.io.File;
+import java.io.IOException;
+
+import javax.ws.rs.core.Response;
+
+public class Utils {
+
+    /**
+     * Creates a File that is unique in the specified directory. If the specified
+     * filename exists in the directory, "-#" will be appended to the filename until
+     * a unique filename can be created.
+     * 
+     * @param directory
+     * @param filename
+     * @return a File that is unique in the specified directory
+     * @throws IOException
+     */
+    public static File createUniqueFile(File directory, String filename) throws IOException {
+
+        File uniqueFile = new File(directory, filename);
+        if (uniqueFile.createNewFile()) {
+            return (uniqueFile);
+        }
+
+        String extension = "";
+        int dotIndex = filename.lastIndexOf('.');
+        if (dotIndex >= 0) {
+            extension = filename.substring(dotIndex);
+            filename = filename.substring(0, dotIndex);
+        }
+
+        int fileNumber = 0;
+        while (!uniqueFile.createNewFile()) {
+            fileNumber++;
+            String numberedFilename = String.format("%s-%d%s", filename, fileNumber, extension);
+            uniqueFile = new File(directory, numberedFilename);
+        }
+
+        return (uniqueFile);
+    }
+
+    /**
+     * Get the filename from the "Content-Disposition" header of a JAX-RS response.
+     * 
+     * @param response the JAX-RS Response instance  to get the "Content-Disposition" header filename from
+     * @return the filename from the "Content-Disposition" header of a JAX-RS response, or null
+     * if the "Content-Disposition" header is not present in the response
+     */
+    public static String getFilenameFromContentDisposition(Response response) {
+
+        String disposition = response.getHeaderString("Content-Disposition");
+        if (disposition == null || disposition.trim().length() == 0)
+            return (null);
+
+        return (disposition.replaceFirst("(?i)^.*filename=\"([^\"]+)\".*$", "$1"));
+    }
+}