1.概述
前面在《ElasticSearch实战－入门》中给大家分享如何搭建这样一个集群，在完成集群的搭建后，今天给大家分享如何实现对应的业务功能模块，下面是今天的分享内容，目录如下所示：
- 编码实践
- 效果预览
- 总结
2.编码实践
由于 ES 集群支持 Restful 接口，我们可以直接通过 Java 来调用 Restful 接口来查询我们需要的数据结果，并将查询到的结果在在我们的业务界面可视化出来。我们知道在 ES 集群的 Web 管理界面有这样一个入口，如下图所示：
我们可以在此界面的入口中拼接 JSON 字符串来查询我们想要的结果，下面，我们通过 Java 的 API 去调用 Restful 接口来查询我们想要的结果。
2.1 字符串拼接实现
接着，我们去实现要查询的核心代码，具体内容实现如下所示：
public String buildQueryString(Map<String, Object> param) throws ParseException {
SimpleDateFormat dfs = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
StringBuilder builder = new StringBuilder("{\"query\":{\"bool\":{\"must\":[");
if (param.get("msgType") != null) {
Integer msgType = (int) param.get("msgType") == 0 ? 2 : 1;
builder.append("{\"term\":{\"msg_type\":").append(msgType).append("}}");
}if (param.get("start") != null && param.get("end") != null) {
String start = String.valueOf(dfs.parse(param.get("start").toString()).getTime()).substring(0, 10);
String end = String.valueOf(dfs.parse(param.get("end").toString()).getTime()).substring(0, 10);
builder.append(",{\"range\":{\"itime\":{\"from\":" + start + ",\"to\":" + end + "}}}");
}
if (param.get("receiverValue") != null) {
builder.append(",{\"wildcard\":{\"receiver_value\":\"*").append(param.get("receiverValue")).append("*\"}}");
}
builder.append("],\"must_not\":[],\"should\":[]}}");
builder.append(",\"sort\":[{\"itime\":\"desc\"}],\"facets\":{}");
builder.append(",\"from\": ").append(param.get("startIndex")).append(",\"size\": ").append(param.get("pageSize")).append("}");
LOG.info("API Query -> " + builder.toString());
return builder.toString();
}
2.2 查询实现核心代码
接着是实现查询的核心代码，具体内容实现如下所示：
public SerachResponse<ApiSent> querySent(Map<String, Object> param) {
SerachResponse<ApiSent> search_result = null;
try {
long time = System.currentTimeMillis();
ResponseWrapper wrapper = httpUtils.sendJson(configService.loadConfig(Configure.API_SENT), buildQueryString(param));
if (wrapper.responseCode == HttpStatus.SC_OK) {
search_result = _gson.fromJson(wrapper.responseContent, new TypeToken<SerachResponse<ApiSent>>() {
}.getType());
LOG.info(String.format("API query ES spent time=%sms", (System.currentTimeMillis() - time)));
return search_result;
} else {
LOG.info(String.format("API query ES spent time=%sms", (System.currentTimeMillis() - time)));
LOG.error(String.format("api sent request es server response not 200,response=%s,exception=%s", wrapper.error, wrapper.exceptionString));
}
} catch (Exception ex) {
LOG.error(String.format("parsed es sent data exception.", ex));
}
return search_result;
}
- Configure类
public class Configure {
public static final String API_SENT = "API_SENT";
｝
2.3 DAO层获取 ES 集群的连接信息
public class ConfigService {
private static Log logger = LogFactory.getLog(ConfigService.class);
@Autowired
private ConfigDao configDao;
@Cacheable("sysConfigCache")
public String loadConfig(String type) {
String value = configDao.getConfig(type);
logger.info(String.format("Load Config,type=%s,value=%s", type, value));
return value;
}
}
- ConfigDao接口
public interface ConfigDao {
String getConfig(String type);
}
其对应的实现内容如下所示：
<select id="getConfig" parameterType="String" resultType="String">
select value from t_system_config where type=#{type}
</select>
DB库存储的 ES 连接信息，如下图所示：
2.4 HTTP 接口的实现代码
关于 HttpUtils 的代码实现较为简单，这里直接附上代码的实现内容，如下所示：
- IHttpUtils 接口
public interface IHttpUtils {
public ResponseWrapper sendJson(String url, String content);
}
- HttpUtils 类实现接口
public class HttpUtils implements IHttpUtils {
private static Logger LOG = Logger.getLogger(HttpUtils.class.getName());
protected static Gson _gson = new Gson();
protected void initSSL() {
try {
TrustManager[] tmCerts = new javax.net.ssl.TrustManager[1];
tmCerts[0] = new SimpleTrustManager();
javax.net.ssl.SSLContext sc = javax.net.ssl.SSLContext.getInstance("SSL");
sc.init(null, tmCerts, null);
javax.net.ssl.HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
HostnameVerifier hv = new SimpleHostnameVerifier();
HttpsURLConnection.setDefaultHostnameVerifier(hv);
} catch (Exception e) {
LOG.error("init SSL exception.", e);
}
}
@Override
public ResponseWrapper sendJson(String url, String content) {
return sendJson(url, content, null);
}
@Override
public ResponseWrapper sendJson(String url, String content, String authCode) {
return sendRequest(url, content, METHOD_POST, authCode, CONTENT_TYPE_JSON);
}
public ResponseWrapper sendRequest(String url, String content, String method, String authCode,
String contentType) {
LOG.info("Send request to - " + url + ", with content - " + content);
HttpURLConnection conn = null;
OutputStream out = null;
StringBuffer sb = new StringBuffer();
cn.jpush.utils.ResponseWrapper wrapper = new ResponseWrapper();
try {
if (StringUtils.isSSL(url)) {
initSSL();
}
if (METHOD_GET.equals(method)) {
if (!Strings.isNullOrEmpty(content)) url += "?" + content;
}
URL aUrl = new URL(url);
wrapper.address = aUrl.getHost();
conn = (HttpURLConnection) aUrl.openConnection();
conn.setConnectTimeout(DEFAULT_CONNECTION_TIMEOUT);
conn.setReadTimeout(DEFAULT_SOCKET_TIMEOUT);
conn.setUseCaches(false);
conn.setRequestMethod(method);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Accept-Charset", CHARSET);
conn.setRequestProperty("Charset", CHARSET);
conn.setRequestProperty("Authorization", authCode);
conn.setRequestProperty("Send-Source", "portal");
conn.setRequestProperty("Content-Type", contentType);
if (METHOD_POST.equals(method)) {
conn.setDoOutput(true);
byte[] data = content.getBytes(CHARSET);
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
out = conn.getOutputStream();
out.write(data);
out.flush();
} else {
conn.setDoOutput(false);
}
int status = conn.getResponseCode();
InputStream in = null;
if (status == 200) {
in = conn.getInputStream();
} else {
in = conn.getErrorStream();
}
InputStreamReader reader = new InputStreamReader(in, CHARSET);
char[] buff = new char[1024];
int len;
while ((len = reader.read(buff)) > 0) {
sb.append(buff, 0, len);
}
String responseContent = sb.toString();
wrapper.responseCode = status;
wrapper.responseContent = responseContent;
String quota = conn.getHeaderField(RATE_LIMIT_QUOTA);
String remaining = conn.getHeaderField(RATE_LIMIT_Remaining);
String reset = conn.getHeaderField(RATE_LIMIT_Reset);
wrapper.setRateLimit(quota, remaining, reset);
if (status == 200) {
LOG.debug("Succeed to get response - 200 OK");
LOG.debug("Response Content - " + responseContent);
} else if (status > 200 && status < 400) {
LOG.warn("Normal response but unexpected - responseCode:" + status
+ ", responseContent:" + responseContent);
} else {
LOG.warn("Got error response - responseCode:" + status + ", responseContent:"
+ responseContent);
switch (status) {
case 400:
LOG.error("Your request params is invalid. Please check them according to error message.");
wrapper.setErrorObject();
break;
case 401:
LOG.error("Authentication failed! Please check authentication params according to docs.");
wrapper.setErrorObject();
break;
case 403:
LOG.error("Request is forbidden! Maybe your is listed in blacklist?");
wrapper.setErrorObject();
break;
case 410:
LOG.error("Request resource is no longer in service. Please according to notice on official website.");
wrapper.setErrorObject();
case 429:
LOG.error("Too many requests! Please review your request quota.");
wrapper.setErrorObject();
break;
case 500:
case 502:
case 503:
case 504:
LOG.error("Seems encountered server error. Maybe is in maintenance? Please retry later.");
break;
default:
LOG.error("Unexpected response.");
}
}
} catch (SocketTimeoutException e) {
if (e.getMessage().contains(KEYWORDS_READ_TIMED_OUT)) {
LOG.error(KEYWORDS_READ_TIMED_OUT, e);
}
wrapper.exceptionString = e.getMessage();
} catch (IOException e) {
LOG.error(KEYWORDS_CONNECT_TIMED_OUT, e);
wrapper.exceptionString = e.getMessage();
} finally {
if (null != out) {
try {
out.close();
} catch (IOException e) {
LOG.error("Failed to close stream.", e);
}
}
if (null != conn) {
conn.disconnect();
}
}
LOG.info(String.format("Send Response to - %s, Response Wrapper - %s", url, wrapper));
return wrapper;
}
}
3.截图预览
下面给大家附上一张业务界面可视化的数据结果预览图，如下图所示：
上图为我发送的测试数据，通过收集模块将我发送的数据收集并存储到 ES 集群，通过接口代码将这部分数据可视化到业务界面进行展示。
4.总结
总体来说，ES 集群从搭建部署到编码实现都较为简单，在使用 JSON 字符串拼接查询时需要细心点，后续有时间可以为大家分享下 ES 的查询的效率，及其他方面的性能指标。
5.结束语
这篇博客就和大家分享到这里，如果大家在研究学习的过程当中有什么问题，可以加群进行讨论或发送邮件给我，我会尽我所能为您解答，与君共勉！