• 原因

java操作elasticsearch的博文很多，大多都是复制粘贴，要不就是过时，抄来抄去没啥意思，所以这个系列就简单记录一下。

• elasticsearch单机或集群搭建

此过程略过

• java连接elasticsearch单机

代码如下:

RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();

// 
ElasticsearchTransport transport = new RestClientTransport( restClient, new JacksonJsonpMapper());

// 
ElasticsearchClient client = new ElasticsearchClient(transport);

很简单吧，把IP和端口代入即可，具体源码就不展开了

csdn博主: liming10101010原创csdn博主: liming10101010原创

带密码就加一个CredentialsProvider，代码如下:

CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(name, pwd));

RestClient restClient = RestClient.builder(new HttpHost("192.168.1.201", 9200, "https"))
                .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider))
                .build();

参数一目了然，是https就在后面加个https即可。

• java连接elasticsearch集群

代码如下：

HttpHost[] httpHosts = {new HttpHost("192.168.1.201", 9200, "https"),
                                new HttpHost("192.168.1.203", 9200, "https"),
                                new HttpHost("192.168.1.203", 9200, "https"),};

 RestClient restClient = RestClient.builder(httpHosts).build();

是不是很容易，so easy，加上密码如下：

opencv for android(二十三)：使用opencv人脸64点位实现人脸装饰物_liming10101010的博客-CSDN博客

CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(name, pwd));

HttpHost[] httpHosts = {new HttpHost("192.168.1.201", 9200, "https"),
                                new HttpHost("192.168.1.203", 9200, "https"),
                                new HttpHost("192.168.1.203", 9200, "https"),};

RestClient restClient = RestClient.builder(httpHosts)
                .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider))
                .build();

• 代码封装如下：

public static init(String hosts, String name, String pwd){
    CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    credentialsProvider.setCredentials(AuthScope.ANY, new     UsernamePasswordCredentials(name, pwd));


     HttpHost[] httpHosts = Arrays.stream(hosts.split(",")).map(x -> {
            String[] hostInfo = x.split(":");
            return new HttpHost(hostInfo[1].replaceAll("//", ""), Integer.parseInt(hostInfo[2]), hostInfo[0]);
        }).toArray(HttpHost[]::new);


     RestClient restClient = RestClient.builder(httpHosts)
                .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider))
                .build();
}

使用就主要这样了:

opencv for android(二十四)：使用opencv的BackgroundSubtractorKNN动态追踪_liming10101010的博客-CSDN博客

String [] hosts = {"192.168.1.200:9200", "192.168.1.201:9200", "192.168.1.202:9200"};
init(hosts, "root", "root");

ok，连接完成