Defining as a "long" or "int" type throws an error on startup

solr启动时候，报如下异常：

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1. SEVERE: org.apache.solr.common.SolrException 
2.         at org.apache.solr.core.SolrCore.<init>(SolrCore.java:600) 
3.         at org.apache.solr.core.CoreContainer.create(CoreContainer.java:480) 
4.         at org.apache.solr.core.CoreContainer.load(CoreContainer.java:332) 
5.         at org.apache.solr.core.CoreContainer.load(CoreContainer.java:216) 
6.         at org.apache.solr.core.CoreContainer$Initializer.initialize(CoreContainer.java:161) 
7.         at org.apache.solr.servlet.SolrDispatchFilter.init(SolrDispatchFilter.java:96) 
8.         at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295) 
9.         at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422) 
10.         at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115) 
11.         at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3838) 
12.         at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771) 
13.         at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:526) 
14.         at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:637) 
15.         at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:563) 
16.         at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:498) 
17.         at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277) 
18.         at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321) 
19.         at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) 
20.         at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) 
21.         at org.apache.catalina.core.StandardHost.start(StandardHost.java:722) 
22.         at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) 
23.         at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443) 
24.         at org.apache.catalina.core.StandardService.start(StandardService.java:516) 
25.         at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) 
26.         at org.apache.catalina.startup.Catalina.start(Catalina.java:593) 
27.         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
28.         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
29.         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
30.         at java.lang.reflect.Method.invoke(Method.java:597) 
31.         at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) 
32.         at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) 
33. Caused by: org.apache.solr.common.SolrException: Error initializing QueryElevationComponent. 
34.         at org.apache.solr.handler.component.QueryElevationComponent.inform(QueryElevationComponent.java:202) 
35.         at org.apache.solr.core.SolrResourceLoader.inform(SolrResourceLoader.java:527) 
36.         at org.apache.solr.core.SolrCore.<init>(SolrCore.java:594) 
37.         ... 32 more 
38. Caused by: java.lang.NumberFormatException: For input string: "MA147LL/A"
39.         at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48) 
40.         at java.lang.Integer.parseInt(Integer.java:449) 
41.         at java.lang.Integer.parseInt(Integer.java:499) 
42.         at org.apache.solr.schema.TrieField.readableToIndexed(TrieField.java:291) 
43.         at org.apache.solr.handler.component.QueryElevationComponent$ElevationObj.<init>(QueryElevationComponent.java:119) 
44.         at org.apache.solr.handler.component.QueryElevationComponent.loadElevationMap(QueryElevationComponent.java:264) 
45.         at org.apache.solr.handler.component.QueryElevationComponent.inform(QueryElevationComponent.java:186) 
46.         ... 34 more 

我的solr版本是3.6.1。

通过查看异常堆栈 ：Caused by: org.apache.solr.common.SolrException: Error initializing QueryElevationComponent.和Caused by: java.lang.NumberFormatException: For input string: "MA147LL/A"

问题定位在初始化QueryElevationComponent组件时失败。在solrconfig.xml文件中找到QueryElevationComponent的配置项：

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1. <searchComponent name="elevator" class="solr.QueryElevationComponent"> 
2. <!--  pick a fieldType to analyze queries  --> 
3. <str name="queryFieldType">string</str> 
4. <str name="config-file">elevate.xml</str> 
5. </searchComponent> 
6. <!-- 
7. A request handler for demonstrating the elevator component  
8. --> 
9. <requestHandler name="/elevate" class="solr.SearchHandler" startup="lazy"> 
10. <lst name="defaults"> 
11. <str name="echoParams">explicit</str> 
12. <str name="df">text</str> 
13. </lst> 
14. <arr name="last-components"> 
15. <str>elevator</str> 
16. </arr> 
17. </requestHandler> 

从配置文件得知在初始化QueryElevationComponent的时候会去加载conf目录下的elevate.xml文件，所以打开elevate.xml文件看看：

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1. <elevate> 
2. <query text="foo bar"> 
3.   <doc id="1" /> 
4.   <doc id="2" /> 
5.   <doc id="3" /> 
6. </query> 
7. <query text="ipod"> 
8.    <doc id="MA147LL/A" />  <!-- put the actual ipod at the top --> 
9.    <doc id="IW-02" exclude="true" /> <!-- exclude this cable --> 
10. </query> 
11. </elevate> 

你会发现有一个id="MA147LL/A"和id="IW-02"的配置项，问题就在于id的值为"MA147LL/A"和IW-02，它是string类型，当我们把所<uniqueKey> id 定义为long或int等number类型时，自然会报以上异常。

这是一个solr的bug：https://issues.apache.org/jira/browse/SOLR-2997

有两种解决方案：

（一）将id="MA147LL/A" 改为id="1"，将id="IW-02"改为id="2"，将其值设为整形。

（一）在solrconfig.xml文件中注释掉以下代码：（QueryElevationComponent组件对于初学者一般上不用，所以可以先注释掉）

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1. <searchComponent name="elevator" class="solr.QueryElevationComponent"> 
2. <!--  pick a fieldType to analyze queries  --> 
3. <str name="queryFieldType">string</str> 
4. <str name="config-file">elevate.xml</str> 
5. </searchComponent> 
6. <!-- 
7. A request handler for demonstrating the elevator component  
8. --> 
9. <requestHandler name="/elevate" class="solr.SearchHandler" startup="lazy"> 
10. <lst name="defaults"> 
11. <str name="echoParams">explicit</str> 
12. <str name="df">text</str> 
13. </lst> 
14. <arr name="last-components"> 
15. <str>elevator</str> 
16. </arr> 
17. </requestHandler> 

PS： QueryElevationComponent组件用于solr实现竞价排名，接下来会写一篇关于solr竞价排名的文章。