Solr 检索数据基础教程文档
收录于 2023-04-20 00:10:05 · بالعربية · English · Español · हिंदीName · 日本語 · Русский язык · 中文繁體
Apache Solr 中检索数据
在本教程页面中,我们将讨论使用 Java 客户端 API 检索数据的方式。例如,我们有一个名为 sample.csv 的 .csv 文档,其中包含以下数据。
001, +148022337, new York, John
002, +148022338, Hawaii, Emma
003, +148022339, Florida, Sophia
我们现在可以使用 post 命令在名为 sample_Solr 的核心下索引这些数据。
[Hadoop@localhost bin]$ ./post-c Solr_sample.csv
下面给出的是 Java 程序,它被编码以将文档添加到 Apache Solr 索引。将代码保存在名为 RetrievingData.java 的文件中。
import java.io.IOException; import org.apache.Solr.client.Solrj.SolrClient; import org.apache.Solr.client.Solrj.SolrQuery; import org.apache.Solr.client.Solrj.SolrServerException; import org.apache.Solr.client.Solrj.impl.HttpSolrClient; import org.apache.Solr.client.Solrj.response.QueryResponse; import org.apache.Solr.common.SolrDocumentList; public class RetrievingData { public static void main(String args[]) throws SolrServerException, IOException { //Preparing the Solr client String urlString = "http://localhost:8983/Solr/my_core"; SolrClient Solr = new HttpSolrClient.Builder(urlString).build(); //Preparing the Solr query SolrQuery query = new SolrQuery(); query.setQuery("*:*"); //Adding the field that has to be retrieved query.addField("*"); //Executing query for data QueryResponse queryResponse = Solr.query(query); //Saving the results of the query SolrDocumentList docs = queryResponse.getResults(); System.out.println(docs); System.out.println(docs.get(0)); System.out.println(docs.get(1)); System.out.println(docs.get(2)); //storing the operations Solr.commit(); } }
在终端执行以下命令编译并运行上述代码-
[Hadoop@localhost bin]$ javac RetrievingData [Hadoop@localhost bin]$ java RetrievingData
运行上面给出的命令,我们将得到以下结果。
{numFound = 3, start = 0, docs = [SolrDocument{id=001, phone = [+148022337], city = [California], first_name = [Olivia], _version_ = 1547262806014820352}, SolrDocument { id = 002, phone = [+148022338], city = [Hawaii], first_name = [Emma], _version_ = 1547262806026354688}, SolrDocument { id = 003, phone = [+148022339], city = [Florida], first_name = [Sophia], _version_ = 1547262806029500416}]} SolrDocument {id = 004, phone = [+148022337], city = [Texas], first_name = [Emily], _version_ = 1547262806014820352}, SolrDocument { id = 002, phone = [+148022338], city = [Hawaii], first_name = [Emma], _version_ = 1547262806026354688}, SolrDocument { id = 003, phone = [+148022339], city = [Florida], first_name = [Sophia], _version_ = 1547262806029500416}