@ResponseBody
public String index() throws Exception {

    SparkConf conf = new SparkConf().setAppName("Simple Application")
            .setMaster("local");

    JavaSparkContext sc = new JavaSparkContext(conf);

    sc.setLogLevel("ERROR");

    SQLContext sqlContext = new SQLContext(sc);

    Map<String, String> options = new HashMap<String, String>();
    options.put("url",
            "jdbc:mysql://127.0.0.1:3306/msp?user=root&password=root");
    options.put("dbtable", "user_info");

    DataFrame df = sqlContext.read().format("jdbc").options(options).load();

    System.out.println(df.count());
    return "index";
}

public static void main(String[] args) throws Exception {

        File file = new File("/home/miaosipeng/ext_jars/spark-servlet.jar");
        Method method = URLClassLoader.class.getDeclaredMethod("addURL",
                URL.class);
        boolean accessible = method.isAccessible();
        try {
            if (accessible == false) {
                method.setAccessible(true);
            }

            URLClassLoader classLoader = (URLClassLoader) ClassLoader
                    .getSystemClassLoader();

            URL url = file.toURI().toURL();
            try {
                method.invoke(classLoader, url);
                System.out.println("读取jar文件[name={}]" + file.getName());
            } catch (Exception e) {
                System.out.println("读取jar文件[name={}]失败" + file.getName());
            }

        } finally {
            method.setAccessible(accessible);
        }

        SparkConf conf = new SparkConf()
                .setAppName("Simple Application")
                .setJars(
                        new String[] { "/home/miaosipeng/ext_jars/spark-servlet.jar" })
                .setMaster("local");

        JavaSparkContext sc = new JavaSparkContext(conf);

        sc.setLogLevel("ERROR");

        SQLContext sqlContext = new SQLContext(sc);

        Map<String, String> options = new HashMap<String, String>();
        options.put("url",
                "jdbc:mysql://127.0.0.1:3306/msp?user=root&password=root");
        options.put("dbtable", "user_info");

        DataFrame df = sqlContext.read().format("jdbc").options(options).load();

        System.out.println(df.count());
    }