本学习笔记基于ElasticSearch 7.10版本，旧版本已经废弃的功能暂时不做笔记，以后有涉及到再做补充。
上一章我们学习了Java高级客户端中的索引部分，现在继续来学习文档管理。
同样，创建一个新的Maven工程，引入依赖。需要注意，依赖的版本和 Es 的版本要对应：
<dependencies>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.10.0</version>
</dependency>
</dependencies>
1、添加文档
public class DocTest1 {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
// 1.构建一个 IndexRequest 请求，参数就是索引名称
IndexRequest request = new IndexRequest("book");
// 2.给请求配置一个 id，这个就是文档 id。如果指定了 id，相当于 put book/_doc/id ，也可以不指定 id，相当于 post book/_doc
request.id("1");
// 3.构建索引文本，有三种方式：JSON 字符串、Map 对象、XContentBuilder
// 首先演示JSON
request.source("{\"name\": \"三国演义\",\"author\": \"罗贯中\"}", XContentType.JSON);
// 4.执行请求，同样有同步和异步两种方式
// 同步
IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
// 5.查看请求响应报文
// 获取文档id
String id = indexResponse.getId();
System.out.println("id = " + id);
// 获取索引名称
String index = indexResponse.getIndex();
System.out.println("index = " + index);
// 判断文档是否添加成功
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
System.out.println("文档添加成功");
}
// 判断文档是否更新成功（如果 id 已经存在）
if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("文档更新成功");
}
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
// 判断分片操作是否都成功
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
System.out.println("有存在问题的分片");
}
// 有存在失败的分片
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
System.out.println("failure.reason() = " + failure.reason());
}
}
//异步
/*client.indexAsync(request, RequestOptions.DEFAULT, new ActionListener<IndexResponse>() {
@Override
public void onResponse(IndexResponse indexResponse) {
}
@Override
public void onFailure(Exception e) {
}
});*/
client.close();
}
}
上面这段代码，在添加文档的时候如果索引不存在，会同步创建索引。因为之前我们设置了创建索引默认的分片和副本都是1，就不会出现分片失败的情况。
为了演示分片失败的情况，我们就需要定义分片数 ≥ 集群数，集群数是3，所以分片数也设置为3：
PUT book
{
"settings": {
"number_of_replicas": 3,
"number_of_shards": 3
}
}
然后我们再来执行上面的代码，就会出现“有存在问题的分片”的情况了。
构建索引文本的另外两种方式：
// 3.构建索引文本，有三种方式：JSON 字符串、Map 对象、XContentBuilder
// 首先演示JSON
// request.source("{\"name\": \"三国演义\",\"author\": \"罗贯中\"}", XContentType.JSON);
//Map<String, String> map = new HashMap<>();
//map.put("name", "水浒传");
//map.put("author", "施耐庵");
//request.source(map).id("99");
XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();
jsonBuilder.startObject();
jsonBuilder.field("name", "西游记");
jsonBuilder.field("author", "吴承恩");
jsonBuilder.endObject();
request.source(jsonBuilder);
2、删除文档
public class DeleteDoc {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
DeleteRequest request = new DeleteRequest("book", "99");
DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
System.out.println("response.getId() = " + response.getId());
System.out.println("response.getIndex() = " + response.getIndex());
System.out.println("response.getVersion() = " + response.getVersion());
ReplicationResponse.ShardInfo shardInfo = response.getShardInfo();
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
System.out.println("有分片存在问题");
}
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
System.out.println("failure.reason() = " + failure.reason());
}
}
client.close();
}
}
删除文档的响应报文和添加文档响应报文类似。
3、获取文档
public class GetDoc {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
GetRequest request = new GetRequest("book", "1");
GetResponse response = client.get(request, RequestOptions.DEFAULT);
String id = response.getId();
String index = response.getIndex();
System.out.println("response.getId() = " + id);
System.out.println("response.getIndex() = " + index);
if (response.isExists()) {
long version = response.getVersion();
System.out.println(version);
String sourceAsString = response.getSourceAsString();
System.out.println(sourceAsString);
} else {
System.out.println("文档不存在");
}
client.close();
}
}
4、判断文档是否存在
判断文档是否存在和获取文档的 API 是类似。只不过在判断文档是否存在时，不需要获取 source。
public class ExistDoc {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
GetRequest request = new GetRequest("book", "1");
// 不需要获取source内容
request.fetchSourceContext(new FetchSourceContext(false));
boolean exists = client.exists(request, RequestOptions.DEFAULT);
System.out.println(exists);
client.close();
}
}
5、更新文档
5.1、painless脚本更新
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
UpdateRequest request = new UpdateRequest("book", "1");
// 通过脚本更新
Map<String, Object> params = Collections.singletonMap("name", "三国演义666");
Script script = new Script(ScriptType.INLINE, "painless", "ctx._source.name=params.name", params);
request.script(script);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
System.out.println("response.getId() = " + response.getId());
System.out.println("response.getIndex() = " + response.getIndex());
System.out.println("response.getVersion() = " + response.getVersion());
if (response.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("更新成功!");
}
client.close();
}
5.2、json更新
// 通过json更新
request.doc("{\"name\": \"三国演义\"}", XContentType.JSON);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
5.3、Map更新
// 通过Map更新
Map<String, Object> docMap = new HashMap<>();
docMap.put("name", "三国演义888");
request.doc(docMap);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
5.4、XContentBuilder更新
// 通过XContentBuilder更新
XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();
jsonBuilder.startObject();
jsonBuilder.field("name", "三国演义666");
jsonBuilder.endObject();
request.doc(jsonBuilder);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
5.5、upsert更新
前面4种更新文档的方式，如果文档id不存在，找不到文档，就会抛出异常。除了更新前判断文档是否存在，还有另一只方法：在更新文档之前，我们可以使用upsert方法设置一个新文档，当文档不存在时添加这个新文档。
public class UpdateDoc {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http"),
new HttpHost("localhost", 9202, "http")
));
UpdateRequest request = new UpdateRequest("book", "2");
// 通过XContentBuilder更新
XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();
jsonBuilder.startObject();
jsonBuilder.field("name", "三国演义666");
jsonBuilder.endObject();
request.doc(jsonBuilder);
request.upsert("{\"name\": \"红楼梦\",\"author\": \"曹雪芹\"}", XContentType.JSON);
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
System.out.println("response.getId() = " + response.getId());
System.out.println("response.getIndex() = " + response.getIndex());
System.out.println("response.getVersion() = " + response.getVersion());
if (response.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("更新成功!");
}
client.close();
}
}
版权声明：
本文仅记录ElasticSearch学习心得，如有侵权请联系删除。
更多内容请访问原创作者：江南一点雨
版权声明：本文不是「本站」原创文章，版权归原作者所有 | 原文地址: