遠端連接

Elastic cloud 透過 Spring 實做遠端連接功能

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一、依賴項

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  
<modelVersion>4.0.0</modelVersion>  

<groupId>org.example</groupId>  
<artifactId>ElasticTest</artifactId>  
<version>1.0-SNAPSHOT</version>  

<name>ElasticTest</name>  
<!-- FIXME change it to the project's website -->  
<url>http://www.example.com</url>  

<properties>  
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
    <maven.compiler.source>1.7</maven.compiler.source>  
    <maven.compiler.target>1.7</maven.compiler.target>  
</properties>  
<repositories>  
    <repository>  
        <id>elasticsearch-releases</id>  
        <url>https://artifacts.elastic.co/maven</url>  
        <releases>  
            <enabled>true</enabled>  
        </releases>  
        <snapshots>  
            <enabled>false</enabled>  
        </snapshots>  
    </repository>  
</repositories>  
<dependencies>  
    <dependency>  
        <groupId>junit</groupId>  
        <artifactId>junit</artifactId>  
        <version>4.11</version>  
        <scope>test</scope>  
    </dependency>  
    <dependency>  
        <groupId>com.fasterxml.jackson.core</groupId>  
        <artifactId>jackson-core</artifactId>  
        <version>2.9.8</version>  
    </dependency>  
    <dependency>  
        <groupId>com.fasterxml.jackson.core</groupId>  
        <artifactId>jackson-databind</artifactId>  
        <version>2.9.8</version>  
    </dependency>  
    <dependency>  
        <groupId>org.elasticsearch.client</groupId>  
        <artifactId>elasticsearch-rest-high-level-client</artifactId>  
        <version>7.12.0</version>  
    </dependency>  
</dependencies>  
<build>  
    <pluginManagement>
        <plugins>  
            <plugin>  
                <artifactId>maven-clean-plugin</artifactId>  
                <version>3.1.0</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-resources-plugin</artifactId>  
                <version>3.0.2</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-compiler-plugin</artifactId>  
                <version>3.8.0</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-surefire-plugin</artifactId>  
                <version>2.22.1</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-jar-plugin</artifactId>  
                <version>3.0.2</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-install-plugin</artifactId>  
                <version>2.5.2</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-deploy-plugin</artifactId>  
                <version>2.8.2</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-site-plugin</artifactId>  
                <version>3.7.1</version>  
            </plugin>  
            <plugin>  
                <artifactId>maven-project-info-reports-plugin</artifactId>  
                <version>3.0.0</version>  
            </plugin>  
        </plugins>  
    </pluginManagement>  
    <plugins>  
        <plugin>  
            <groupId>org.apache.maven.plugins</groupId>  
            <artifactId>maven-compiler-plugin</artifactId>  
            <configuration>  
                <source>8</source>  
                <target>8</target>  
            </configuration>  
        </plugin>  
    </plugins>  
</build>  
</project>

二、取資料

package org.example;  

import org.apache.http.HttpHost;  
import org.apache.http.auth.AuthScope;  
import org.apache.http.auth.UsernamePasswordCredentials;  
import org.apache.http.client.CredentialsProvider;  
import org.apache.http.impl.client.BasicCredentialsProvider;  
import org.elasticsearch.action.search.SearchRequest;  
import org.elasticsearch.client.*;  
import org.elasticsearch.search.SearchHit;  
import org.elasticsearch.search.SearchHits;  
import org.elasticsearch.search.builder.SearchSourceBuilder;  

import java.io.IOException;  
import java.util.Map;  




public class App
{
    public static void main(String[] args ) throws IOException 
    {

        // 建立連線端
        String username = "yourUserName";
        String password = "yourPassword";
        String host = "yourHost"; //  like  0b48338694f94e48a6a2ba77d7ddcbba.asia-east1.gcp.elastic-cloud.com
        int port = 9243;
        int nextPort = 9244;
        String protocol = "https";


        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(
            AuthScope.ANY,
            new UsernamePasswordCredentials(username, password));
            RestClientBuilder Builder = RestClient.builder(
            new HttpHost(host, port, protocol),
            new HttpHost(host, nextPort, protocol))
            .setHttpClientConfigCallback((h) -> h.setDefaultCredentialsProvider(credentialsProvider));

        try (RestHighLevelClient client = new RestHighLevelClient(Builder)) 
        {

            SearchSourceBuilder searchBuilder = SearchSourceBuilder.searchSource();

            //  index 的名稱
            SearchRequest request = new SearchRequest("item").source(searchBuilder);

            SearchHits hits = client.search(request, RequestOptions.DEFAULT).getHits();

            System.out.println(hits);
            // 逐筆取資料
            for(SearchHit hit : hits)
            {
                Map<String, Object> sourceAsMap = hit.getSourceAsMap();  
                System.out.println(sourceAsMap);  

                String user = (String) sourceAsMap.get("user");  
                String post_date = (String) sourceAsMap.get("post_date");  
                String message = (String) sourceAsMap.get("message");  

                System.out.println(String.format("user:%s data:%s message:%s",user , post_date, message));  
            }  
        }catch (IOException ignored) 
        {

        }  
    }  
}

在建立Elastic Cloud的時候，會產生一份包含使用者名稱與密碼的Excel檔案

Host 取得參照下圖，如果Host 含有Protocol 與 Port，則需要手動去除