Spring Data Solr：聲明字段時如何將multiValue設置爲false

Question

我正在使用帶有Schemaless Solr的Spring Data Solr。有些點我無法連接：何時以及如何創建模式字段？

The following page states

自動架構人口將檢查您的域名類型，每當應用程序上下文是刷新並填充新的領域，基於性能配置索引。這要求solr以無模式模式運行。

使用@Indexed提供更多詳細信息，如使用特定的solr類型。

它還正好說明捲曲請求：

//捲曲../solr/collection1/schema/fields -X POST -H '內容類型：應用/ JSON'

但是，當我運行一個帶有@Indexed註釋的字段的簡單示例時，我看不到在SOLR上調用的/ schema/fields API。這些字段是如何創建的？

我問的原因是他們似乎是自動創建multiValued = true。我沒有看到@Indexed註釋採用multiValued作爲參數。如何強制Spring Data Solr在創建它們時將這些字段聲明爲非multiValued？

現在，所有這些都是爲了解決我所看到的這個異常。

java.lang.IllegalArgumentException: [Assertion failed] - this argument is required; it must not be null 
at org.springframework.util.Assert.notNull(Assert.java:115) 
at org.springframework.util.Assert.notNull(Assert.java:126) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$SolrPropertyValueProvider.readValue(MappingSolrConverter.java:426) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$SolrPropertyValueProvider.readCollection(MappingSolrConverter.java:601) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$SolrPropertyValueProvider.readValue(MappingSolrConverter.java:440) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$SolrPropertyValueProvider.readValue(MappingSolrConverter.java:412) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$SolrPropertyValueProvider.getPropertyValue(MappingSolrConverter.java:395) 
at org.springframework.data.solr.core.convert.MappingSolrConverter.getValue(MappingSolrConverter.java:206) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$1.doWithPersistentProperty(MappingSolrConverter.java:194) 
at org.springframework.data.solr.core.convert.MappingSolrConverter$1.doWithPersistentProperty(MappingSolrConverter.java:186) 
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:309) 
at org.springframework.data.solr.core.convert.MappingSolrConverter.read(MappingSolrConverter.java:186) 
at org.springframework.data.solr.core.convert.MappingSolrConverter.read(MappingSolrConverter.java:174) 
at org.springframework.data.solr.core.convert.MappingSolrConverter.read(MappingSolrConverter.java:149) 
at org.springframework.data.solr.core.SolrTemplate.convertSolrDocumentListToBeans(SolrTemplate.java:560) 
at org.springframework.data.solr.core.SolrTemplate.convertQueryResponseToBeans(SolrTemplate.java:552) 
at org.springframework.data.solr.core.SolrTemplate.createSolrResultPage(SolrTemplate.java:369) 
at org.springframework.data.solr.core.SolrTemplate.doQueryForPage(SolrTemplate.java:300) 
at org.springframework.data.solr.core.SolrTemplate.queryForPage(SolrTemplate.java:308) 
at org.springframework.data.solr.repository.support.SimpleSolrRepository.findAll(SimpleSolrRepository.java:111) 
at org.springframework.data.solr.repository.support.SimpleSolrRepository.findAll(SimpleSolrRepository.java:106) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
at java.lang.reflect.Method.invoke(Method.java:498) 
at 

我的猜測是異常發生是因爲值作爲集合返回？

我試着通過代碼來了解發生了什麼。導致問題的字段是「名稱」，值是[product-1]。嘗試將solr文檔解組爲POJO時發生異常。

首先，我們去下面的方法中：

private <T> T readValue(Object value, TypeInformation<?> type, Object parent) { 
     if (value == null) { 
      return null; 
     } 

     Assert.notNull(type); 
     Class<?> rawType = type.getType(); 
     if (hasCustomReadTarget(value.getClass(), rawType)) { 
      return (T) convert(value, rawType); 
     } 

     Object documentValue = null; 
     if (value instanceof SolrInputField) { 
      documentValue = ((SolrInputField) value).getValue(); 
     } else { 
      documentValue = value; 
     } 

     if (documentValue instanceof Collection) { 
      return (T) readCollection((Collection<?>) documentValue, type, parent); 
     } else if (canConvert(documentValue.getClass(), rawType)) { 
      return (T) convert(documentValue, rawType); 
     } 

     return (T) documentValue; 

    } 

調用此方法時，該值是一個集合，類型爲java.lang.String的。這導致如果（documentValue的instanceof集合）被選擇，這導致進入下面的方法被執行：

 private Object readCollection(Collection<?> source, TypeInformation<?> type, Object parent) { 
     Assert.notNull(type); 

     Class<?> collectionType = type.getType(); 
     if (CollectionUtils.isEmpty(source)) { 
      return source; 
     } 

     collectionType = Collection.class.isAssignableFrom(collectionType) ? collectionType : List.class; 

     Collection<Object> items; 
     if (type.getType().isArray()) { 
      items = new ArrayList<Object>(); 
     } else { 
      items = CollectionFactory.createCollection(collectionType, source.size()); 
     } 

     TypeInformation<?> componentType = type.getComponentType(); 

     Iterator<?> it = source.iterator(); 
     while (it.hasNext()) { 
      items.add(readValue(it.next(), componentType, parent)); 
     } 

     return type.getType().isArray() ? convertItemsToArrayOfType(type, items) : items; 
    } 

在該方法中，我們最終調用type.getComponentType（），它返回零，並最終導致斷言。 notNull（）失敗。

我在這一切中失去了什麼？

我的代碼如下。啓動和配置類：

@Configuration 
@ComponentScan 
@EnableAutoConfiguration 
@EnableSolrRepositories(schemaCreationSupport=true, basePackages = { "com.example.solrdata" }, multicoreSupport = true) 
public class Application { 

public static void main(String[] args) { 
    SpringApplication.run(Application.class, args); 
} 
} 

模型類：

@SolrDocument(solrCoreName = "collection1") 
public class Product { 

@Id 
String id; 
@Indexed 
String name; 

public Product(String id, String name) { 
    this.id = id; 
    this.name = name; 
} 

public Product() { 
    super(); 
} 

public String getId() { 
    return id; 
} 

public void setId(String id) { 
    this.id = id; 
} 

public String getName() { 
    return name; 
} 

public void setName(String name) { 
    this.name = name; 
}} 

庫：

public interface ProductRepository extends SolrCrudRepository<Product, String> {} 

測試類：

@RunWith(SpringJUnit4ClassRunner.class) 
@SpringApplicationConfiguration(Application.class) 
public class SolrProductRepositoryTest { 

@Autowired 
private ProductRepository repo; 

@Before @After 
public void setup(){ 
    repo.deleteAll(); 
} 

@Test 
public void testCRUD() { 
    assertEquals(0, repo.count()); 
    Product product = new Product("1","product-1"); 
    repo.save(product); 
    assertEquals(1, repo.count()); 
    Product product2 = repo.findOne(product.getId()); 
    assertEquals(product2.getName(), product.getName()); 
}} 

最後，我POM：

<parent> 
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring-boot-starter-parent</artifactId> 
    <version>1.3.3.RELEASE</version> 
</parent> 

<dependencies> 
    <dependency> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-web</artifactId> 
    </dependency> 
    <dependency> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-test</artifactId> 
     <scope>test</scope> 
    </dependency> 
    <dependency> 
     <groupId>org.springframework.data</groupId> 
     <artifactId>spring-data-solr</artifactId> 
    </dependency> 
</dependencies> 

Answer 1

當使用Solr的4.10與默認不幸在solrconfig.xml的JSONResponseWriter使用text/pain作爲內容類型。

<queryResponseWriter name="json" class="solr.JSONResponseWriter"> 
    <str name="content-type">text/plain; charset=UTF-8</str> 
</queryResponseWriter> 

這導致的SolrSchemaRequest內容類型協商默默地失敗並跳過架構更新步驟 - 和Solr默認字段類型在那個地方猜測踢。

設置content-type到application/json允許根據bean定義添加字段。

@SolrDocument(solrCoreName = "collection1") 
public static class SomeDomainType { 

    @Indexed @Id 
    String id; 

    @Indexed 
    String indexedStringWithoutType; 

    @Indexed(name = "namedField", type = "string", searchable = false) 
    String justAStoredField; 

    @Indexed 
    List<String> listField; 

    @Indexed(type = "tdouble") 
    Double someDoubleValue; 
} 

以前

{ 
    responseHeader: { 
     status: 0, 
     QTime: 86 
    }, 
    fields: [ 
     { 
      name: "_version_", 
      type: "long", 
      indexed: true, 
      stored: true 
     }, 
     { 
      name: "id", 
      type: "string", 
      multiValued: false, 
      indexed: true, 
      required: true, 
      stored: true, 
      uniqueKey: true 
     } 
    ] 
} 

架構Upate

{ 
    responseHeader: { 
     status: 0, 
     QTime: 1 
    }, 
    fields: [ 
     { 
      name: "_version_", 
      type: "long", 
      indexed: true, 
      stored: true 
     }, 
     { 
      name: "id", 
      type: "string", 
      multiValued: false, 
      indexed: true, 
      required: true, 
      stored: true, 
      uniqueKey: true 
     }, 
     { 
      name: "indexedStringWithoutType", 
      type: "string", 
      multiValued: false, 
      indexed: true, 
      required: false, 
      stored: true 
     }, 
     { 
      name: "listField", 
      type: "string", 
      multiValued: true, 
      indexed: true, 
      required: false, 
      stored: true 
     }, 
     { 
      name: "namedField", 
      type: "string", 
      multiValued: false, 
      indexed: false, 
      required: false, 
      stored: true 
     }, 
     { 
      name: "someDoubleValue", 
      type: "tdouble", 
      multiValued: false, 
      indexed: true, 
      required: false, 
      stored: true 
     } 
    ] 
}