ElasticSearch—通过Elasticsearch RestFul搜索查询

       ElasticSearch在执行CRUD操作时，可以通过调用上层的java api，也可以通过 Jest Restful的方式进行CRUD操作。通过Jest Restful的方式获得的结果一般为com.google.gson.JsonArray，需要对该Json数组进行解析，获取所需的内容，下面给出一个分页查询的demo。

import java.io.IOException;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.junit.Test;

import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

import edu.fzu.cmp.common.exception.MetaManagerException;
import edu.fzu.cmp.common.exception.QueryException;
import io.searchbox.client.JestClient;
import io.searchbox.client.JestClientFactory;
import io.searchbox.client.config.HttpClientConfig;
import io.searchbox.core.Search;
import io.searchbox.core.SearchResult;
import junit.framework.TestCase;

public class EsQueryByRestful extends TestCase {

	private static String connUrl = "http://belasticsearch1:9200";
	private static String index = "contentmanagerdata_index";
	private static String indexType = "contentmanagerdata_type";
	private static SearchResult result = null;

	@Test
	public void testEsRestful() throws QueryException, MetaManagerException, IOException {
		// 1. connect
		JestClient client = getClient();
		// 2. prepare query param
		String queryParamJson = buildQueryParamByAPI();
		// 3. search
		result = search(client, queryParamJson);
		// 4. get response
		getContent();

	}

	public static JestClient getClient() {
		JestClientFactory factory = new JestClientFactory();
		factory.setHttpClientConfig(new HttpClientConfig.Builder(connUrl).multiThreaded(true).build());
		JestClient client = factory.getObject();
		return client;
	}

	/**利用from-size的方式进行分页查询， 可以通过searchSourceBuilder.query(queryBuilder)的方式设置查询条件*/
	public static String buildQueryParamByAPI() throws QueryException, MetaManagerException {
		int pageNumber = 1;
		int pageSize = 11;
		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
		// searchSourceBuilder.query(queryBuilder);
		searchSourceBuilder.from((pageNumber - 1) * pageSize);// 设置起始页
		searchSourceBuilder.size(pageSize);// 设置页大小
		return searchSourceBuilder.toString();
	}

	public static String buildQueryParamByStr() {
		String queryParamJson = "{\"query\" : {\"match\" : {\"empname\" : \"emp2\"}}}";
		return queryParamJson;
	}

	public static SearchResult search(JestClient client, String queryParamJson) throws IOException {
		Search search = new Search.Builder(queryParamJson)
				// multiple index or types can be added.
				.addIndex(index).addType(indexType).build();
		// JestResult result = client.execute(search);
		SearchResult result = client.execute(search);
		return result;
	}

	public static void getContent() {

		// 自动解析
		JsonObject jsonObject = result.getJsonObject();
		JsonObject hitsobject = jsonObject.getAsJsonObject("hits");
		long took = jsonObject.get("took").getAsLong();   //统计耗时
		long total = hitsobject.get("total").getAsLong();
		System.out.println("took:" + took + " " + "total:" + total);;
		JsonArray recordObject = hitsobject.getAsJsonArray("hits"); 
		/**通过下面的代码解析JsonArray的内容*/
		System.out.println(recordObject.size());
		System.out.println(recordObject.get(0).toString().split(",")[2]);  
	}

//	public static Map<String, String> generateQueryCondtion() {
//		Map<String, String> queryCondition = new HashMap<>();
//		int ra1 = (int) (Math.random() * 10);
//		int ra2 = (int) (Math.random() * 3);
//		queryCondition.put("MAINRISKNAME", ra2 + "");
//		queryCondition.put("INSURANCENO", "O" + String.valueOf((ra1 + 1) * 3)); 
//		queryCondition.put("POLICYHOLDERNAME", ra2 + ""); 
//		return queryCondition;
//	}

}

运行结果：

ES索引库中的已有记录数：