你好，我正在尝试从elasticsearch读取数据。我的代码如下：，

SparkConf sparkConf = new SparkConf()
        .setAppName("Spark ES Integration").setMaster("local");
// .set("spark.ui.port", "7077");
sparkConf.set("es.nodes", "xx.xx.xx.xx");
sparkConf.set("es.port", "9200");
sparkConf.set("es.resource", "blog/post");
sparkConf.set("es.query", "?q=user:dilbert");
JavaSparkContext sc = new JavaSparkContext(sparkConf);

JavaPairRDD<String, Map<String, Object>> esRDD = JavaEsSpark.esRDD(sc);
System.out.println("**********" + esRDD.count()); // Prints 1 - Only one record is present
System.out.println("**********" + esRDD.first()); // Throws exception

程序输出计数正确，但从rdd获取第一条记录时引发异常。当我只想读取数据时，为什么请求是post类型？这里怎么了？配置中提到的查询正确执行。
例外情况是
org.elasticsearch.hadoop.rest.eshadopopinvalidrequest:[post]在[blog/post/\u search？search\u type=scan&scroll=5m&size=50&preference=_shards:0;_仅限_node:03oynb7btjg2vozo9lsnzq]失败；服务器[null]返回[400 |错误请求：]。3091[executor task launch worker-0]error org.apache.spark.executor.executor-0.0阶段任务0.0中的异常（tid 0）org.apache.spark.util.taskcompletionlistenerexception:[post]on[blog/post/\u search？search\u type=scan&scroll=5m&size=50&preference=_shards:0;_仅限_node:03oynb7btjg2vozo9lsnzq]失败；服务器[null]返回[400 |错误请求：]。3099[task-result-getter-0]警告org.apache.spark.scheduler.tasksetmanager-任务丢失