ElasticSearch学习笔记之三十 JAVA Client 之 文档请求概述
Document APIs(文档APIS)
Java High Level REST Client支持下面的文档APIS
单文档APIs
- Index API
- Get API
- Delete API
- Update API
多文档操作 APIs
- Bulk API
- Multi-Get API
Index API
Index Request(索引请求)
一个IndexRequest就像下面案例一样：
IndexRequest request = new IndexRequest(
"posts", // Index
"doc", // Type
"1"); // Document id
//JSON字符串请求体
String jsonString = "{" +
"\"user\":\"kimchy\"," +
"\"postDate\":\"2013-01-30\"," +
"\"message\":\"trying out Elasticsearch\"" +
"}";
request.source(jsonString, XContentType.JSON);
Providing the document source(构建文档请求体)
除了上面所示的字符串示例之外，还可以以不同的方式构建文档请求体。
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");
IndexRequest indexRequest = new IndexRequest("posts", "doc", "1")
.source(jsonMap);
用Map构建文档请求体会自动转为JSON格式。
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
builder.field("user", "kimchy");
builder.timeField("postDate", new Date());
builder.field("message", "trying out Elasticsearch");
}
builder.endObject();
IndexRequest indexRequest = new IndexRequest("posts", "doc", "1")
.source(builder);
ElasticSearch内置XContentBuilder可以用来帮我们构建JSON请求体。
IndexRequest indexRequest = new IndexRequest("posts", "doc", "1")
.source("user", "kimchy",
"postDate", new Date(),
"message", "trying out Elasticsearch");
用键值对构建请求体也会自动转为JSON格式。
Optional arguments(功能参数)
下面的案例展示功能配置
request.routing("routing"); //Routing value
request.parent("parent"); //Parent value
//等待主分片响应的超时时间
request.timeout(TimeValue.timeValueSeconds(1));
//字符串配置主分片响应的超时时间
request.timeout("1s");
//设置刷新策略为WriteRequest.RefreshPolicy
request.setRefreshPolicy(WriteRequest.RefreshPolicy.WAIT_UNTIL);
//字符设置
request.setRefreshPolicy("wait_for");
//版本设置
request.version(2);
//设置版本类型
request.versionType(VersionType.EXTERNAL);
//设置操作类型为DocWriteRequest.OpType
request.opType(DocWriteRequest.OpType.CREATE);
//字符串设置，可以配置create or update (default)
request.opType("create");
//设置在索引文档之前要执行的摄取管道的名称
request.setPipeline("pipeline");
Synchronous Execution(同步执行)
IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
Asynchronous Execution(异步执行)
索引请求的异步执行需要将IndexRequest实例和ActionListener实例传递给异步方法：
client.indexAsync(request/*需要执行的IndexRequest*/, RequestOptions.DEFAULT, listener/*执行完成之后的回调*/);
异步执行不会堵塞并且立即返回，一旦完成，如果执行成功完成，则使用onResponse方法回调ActionListener，如果执行失败，则使用onFailure方法回调ActionListener。
IndexResponse 典型的ActionListener例如：
ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
//调用成功时回调，返回信息作为参数传入
@Override
public void onResponse(IndexResponse indexResponse) {
}
//调用失败时回调，错误信息作为参数传入
@Override
public void onFailure(Exception e) {
}
};
Index Response(索引返回)
从IndexResponse获取返回的响应信息方式如下：
String index = indexResponse.getIndex();
String type = indexResponse.getType();
String id = indexResponse.getId();
long version = indexResponse.getVersion();
//文档创建成功操作
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
//文档更新成功操作
} else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
}
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
//检查成功的分片是不是等于总分片
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
}
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
//获取分片失败的原因
String reason = failure.reason();
}
}
如果版本冲突，我们会得到这样的ElasticsearchException:
IndexRequest request = new IndexRequest("posts", "doc", "1")
.source("field", "value")
.version(1);
try {
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
} catch(ElasticsearchException e) {
//版本冲突错误
if (e.status() == RestStatus.CONFLICT) {
}
}
当我们把opType 设置为 create 但是存在相同的 index, type 和 id :
IndexRequest request = new IndexRequest("posts", "doc", "1")
.source("field", "value")
.opType(DocWriteRequest.OpType.CREATE);
try {
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
} catch(ElasticsearchException e) {
if (e.status() == RestStatus.CONFLICT) {
}
}
完整案例如下：
配置Maven pom.xml依赖（改为对应ES版本）：
<!-- https://mvnrepository.com/artifact/org.elasticsearch/elasticsearch -->
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>6.2.4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.elasticsearch.client/transport -->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.2.4</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>6.2.4</version>
</dependency>
这里，我们使用 ObjectMapper将JavaBean转为JSON请求体，对应有以下依赖：
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.6</version>
</dependency>
//创建连接
//创建连接
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("192.168.199.18", 9200, "http"),
new HttpHost("192.168.199.118", 9200, "http")));
//创建请求
IndexRequest request = new IndexRequest(
"posts", // Index
"doc", // Type
"1"); // Document id
//构建请求体(这里演示ObjectMapper将JavaBean转为JSON请求体)
JavaBean bean = new JavaBean();
ObjectMapper objectMapper = new ObjectMapper();//create once reuse
// generate json
String json = null;
try {
json = objectMapper.writeValueAsString(bean);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
request.source(json, XContentType.JSON);
//设置操作类型为DocWriteRequest.OpType
request.opType(DocWriteRequest.OpType.CREATE);
ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
//调用成功时回调，返回信息作为参数传入
@Override
public void onResponse(IndexResponse indexResponse) {
System.out.println("异步回调成功");
String index = indexResponse.getIndex();
String type = indexResponse.getType();
String id = indexResponse.getId();
long version = indexResponse.getVersion();
//文档创建成功操作
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
System.out.println(index+ type+ id+ version);
//文档更新成功操作
} else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
}
}
//调用失败时回调，错误信息作为参数传入
@Override
public void onFailure(Exception e) {
e.printStackTrace();
}
};
//异步操作
//client.indexAsync(request/*需要执行的IndexRequest*/, listener/*执行完成之后的回调*/);
//同步操作
try {
client.index(request);
} catch (IOException e) {
e.printStackTrace();
}
//关闭连接
if(client !=null){
try {
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}