ElasticSearch6.X版本Java Api中文詳解（五）之Multi Get API、Bulk API解析

1.Multi Get API

multi get API允許根據它們的索引、類型和id獲取文檔列表：

MultiGetResponse multiGetItemResponses = client.prepareMultiGet()
    .add("twitter", "tweet", "1")           
    .add("twitter", "tweet", "2", "3", "4") 
    .add("another", "type", "foo")          
    .get();

for (MultiGetItemResponse itemResponse : multiGetItemResponses) { 
    GetResponse response = itemResponse.getResponse();
    if (response.isExists()) {                      
        String json = response.getSourceAsString(); 
    }
}

2.Bulk API

bulk API允許一個人在單個請求中索引和刪除多個文檔。這裏有一個示例用法：

import static org.elasticsearch.common.xcontent.XContentFactory.*;

BulkRequestBuilder bulkRequest = client.prepareBulk();

// either use client#prepare, or use Requests# to directly build index/delete requests
bulkRequest.add(client.prepareIndex("twitter", "tweet", "1")
        .setSource(jsonBuilder()
                    .startObject()
                        .field("user", "kimchy")
                        .field("postDate", new Date())
                        .field("message", "trying out Elasticsearch")
                    .endObject()
                  )
        );

bulkRequest.add(client.prepareIndex("twitter", "tweet", "2")
        .setSource(jsonBuilder()
                    .startObject()
                        .field("user", "kimchy")
                        .field("postDate", new Date())
                        .field("message", "another post")
                    .endObject()
                  )
        );

BulkResponse bulkResponse = bulkRequest.get();
if (bulkResponse.hasFailures()) {
    // process failures by iterating through each bulk response item
}