ElasticSearch text字段排序报错 Fielddata is disabled on text fields by default. Set fielddata=true

在spring中使用 sourceBuilder.sort(“city”, SortOrder.DESC);排序时，发现查询数字或者时间类型的字段时，排序正常，改为中英文字段排序时就报错了！

为什么报错了？
因为text字段会被es拆分成多个组合字段，便于查询。而排序需要完整的字段排序，所以无法排序。

ElasticsearchStatusException[Elasticsearch exception [type=search_phase_execution_exception, reason=all shards failed]]; nested: ElasticsearchException[Elasticsearch exception [type=illegal_argument_exception, reason=Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]]; nested: ElasticsearchException[Elasticsearch exception [type=illegal_argument_exception, reason=Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]];
	at org.elasticsearch.rest.BytesRestResponse.errorFromXContent(BytesRestResponse.java:177)
	at org.elasticsearch.client.RestHighLevelClient.parseEntity(RestHighLevelClient.java:1727)
	at org.elasticsearch.client.RestHighLevelClient.parseResponseException(RestHighLevelClient.java:1704)
	at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:1467)
	at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:1424)
	at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:1394)
	at org.elasticsearch.client.RestHighLevelClient.search(RestHighLevelClient.java:930)
	at top.zaax.seo.service.BrowseRecordService.escurrentBrowseRecord(BrowseRecordService.java:239)
	at sun.reflect.GeneratedMethodAccessor416.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45005)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
	at com.sun.proxy.$Proxy37.escurrentBrowseRecord(Unknown Source)
	at top.zaax.seo.controller.BrowseRecordController.escurrentBrowseRecord(BrowseRecordController.java:42)
	at sun.reflect.GeneratedMethodAccessor415.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45005)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:817)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:731)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:968)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:870)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:844)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at top.zaax.seo.base.MyFilter.doFilter(MyFilter.java:177)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
	at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:96)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:41002)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
	Suppressed: org.elasticsearch.client.ResponseException: method [POST], host [http://127.0.0.1:9200], URI [/browse_record/_search?typed_keys=true&ignore_unavailable=false&expand_wildcards=open&allow_no_indices=true&ignore_throttled=true&search_type=query_then_fetch&batched_reduce_size=512&ccs_minimize_roundtrips=true], status line [HTTP/1.1 400 Bad Request]
{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}],"type":"search_phase_execution_exception","reason":"all shards failed","phase":"query","grouped":true,"failed_shards":[{"shard":0,"index":"test","node":"Bz1tw0BcQkCP2ae","reason":{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}}],"caused_by":{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.","caused_by":{"type":"illegal_argument_exception","reason":"Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}}},"status":400}
		at org.elasticsearch.client.RestClient.convertResponse(RestClient.java:253)
		at org.elasticsearch.client.RestClient.performRequest(RestClient.java:231)
		at org.elasticsearch.client.RestClient.performRequest(RestClient.java:205)
		at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:1454)
		... 57 more
Caused by: ElasticsearchException[Elasticsearch exception [type=illegal_argument_exception, reason=Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]]; nested: ElasticsearchException[Elasticsearch exception [type=illegal_argument_exception, reason=Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]];
	at org.elasticsearch.ElasticsearchException.innerFromXContent(ElasticsearchException.java:491)
	at org.elasticsearch.ElasticsearchException.fromXContent(ElasticsearchException.java:402)
	at org.elasticsearch.ElasticsearchException.innerFromXContent(ElasticsearchException.java:432)
	at org.elasticsearch.ElasticsearchException.failureFromXContent(ElasticsearchException.java:598)
	at org.elasticsearch.rest.BytesRestResponse.errorFromXContent(BytesRestResponse.java:169)
	... 60 more
Caused by: ElasticsearchException[Elasticsearch exception [type=illegal_argument_exception, reason=Fielddata is disabled on text fields by default. Set fielddata=true on [city] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.]]
	at org.elasticsearch.ElasticsearchException.innerFromXContent(ElasticsearchException.java:491)
	at org.elasticsearch.ElasticsearchException.fromXContent(ElasticsearchException.java:402)
	at org.elasticsearch.ElasticsearchException.innerFromXContent(ElasticsearchException.java:432)
	... 64 more

百度谷歌了许久，说是有两种方法：

1.修改字段的类型为true ， “fielddata”: true ，缺点是非常耗内存，官方说的，具体也没查到测试结果到底多耗多少内存，所以不敢用。

PUT you_index/_mapping/
{
  "properties": {
    "字段":{
      "type": "text",
      "fielddata": true
    }
  }
}

2.将该字段定义为multi-filed。

PUT you_index
{
  "mappings": {
    "my_type": {
      "properties": {
        "city": {
          "type": "text",
          "fields": {
            "raw": { 
              "type":  "keyword"
            }
          }
        }
      }
    }
  }
}

排序的时候使用 city.raw字段，意思就是录入数据的时候给这个排序字段添加一个完整不拆分的专用排序字段，然后如果需要排序就用这个字段排序！
这样做的缺点就是：如果数据非常大，将会多占用硬盘空间！而且还要设置到修改mapping，甚至是需要重建索引，会比较麻烦！

那么有其他更方便的方法吗？有!

  sourceBuilder.sort(“city.keyword”, SortOrder.DESC);

给字段加上.keyword 表示使用完整的字段，无需修改es，也无需修改代码逻辑

我使用的es7版本，spring中测试可以正常排序。