查询OpenTSDB数据
功能简介
使用OpenTSDB的查询接口(/api/query)读取数据。
函数genQueryReq()生成查询请求,函数queryData()把查询请求发送到OpenTSDB服务端。
样例代码
以下代码片段在com.huawei.bigdata.opentsdb.examples包的"OpentsdbExample"类的queryData方法中。
private void queryData(String dataPoint) {
QUERY_URL = BASE_URL + dataPoint;
LOG.info("start to query data in opentsdb, the url is " + QUERY_URL);
try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
HttpPost httpPost = new HttpPost(QUERY_URL);// 请求需要设置超时时间
addTimeout(httpPost);
String queryRequest = genQueryReq();
StringEntity entity = new StringEntity(queryRequest, "utf-8");
entity.setContentType("application/json");
httpPost.setEntity(entity);
HttpResponse response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
LOG.info("Status Code : " + statusCode);
if (statusCode != HttpStatus.SC_OK) {
LOG.info("Request failed! " + response.getStatusLine());
}
String body = EntityUtils.toString(response.getEntity(), "utf-8");
LOG.info("Response content : " + body);
LOG.info("query data to opentsdb successfully.");
} catch (IOException e) {
LOG.error("Failed to query data.", e);
}
}
static class Query {
public Long start;
public Long end;
public boolean delete = false;
public List<SubQuery> queries;
}
static class SubQuery {
public String metric;
public String aggregator;
public SubQuery(String metric, String aggregator) {
this.metric = metric;
this.aggregator = aggregator;
}
}
String genQueryReq() {
Query query = new Query();
query.start = 1498838400L;
query.end = 1498921200L;
query.queries = ImmutableList.of(new SubQuery("city.temp", "sum"), new SubQuery("city.hum", "sum"));
Gson gson = new Gson();
return gson.toJson(query);
}