具有 spring-data-mongodb 存储库的持久路径对象
Persisting Path objects with spring-data-mongodb respositories
在一个项目中，我使用 spring-boot-starter-data-mongodb:2.5.3，因此 spring-data-mongodb:3.2.3 并且有一个简化的实体 class，如下所示：
@Document
public class Task {
@Id
private final String id;
private final Path taskDir;
...
// constructor, getters, setters
}
使用默认 Spring Mongo允许通过其 ID 检索任务的数据库存储库。
Mongo 配置如下所示：
@Configuration
@EnableMongoRepositories(basePackages = {
"path.to.repository"
}, mongoTemplateRef = MongoConfig.MONGO_TEMPLATE_REF)
@EnableConfigurationProperties(MongoSettings.class)
public class MongoConfig extends MongoConfigurationSupport {
private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public static final String MONGO_TEMPLATE_REF = "mongoAlTemplate";
private final MongoSettings mongoSettings;
@Autowired
public MongoConfig(final MongoSettings mongoSettings) {
this.mongoSettings = mongoSettings;
}
@Bean(name = "ourMongo", destroyMethod = "close")
public MongoClient ourMongoClient() {
MongoCredential credential =
MongoCredential.createCredential(mongoSettings.getUser(),
mongoSettings.getDb(),
mongoSettings.getPassword());
MongoClientSettings clientSettings = MongoClientSettings.builder()
.readPreference(ReadPreference.primary())
// enable optimistic locking for @Version and eTag usage
.writeConcern(WriteConcern.ACKNOWLEDGED)
.credential(credential)
.applyToSocketSettings(
builder -> builder.connectTimeout(15, TimeUnit.SECONDS)
.readTimeout(1, TimeUnit.MINUTES))
.applyToConnectionPoolSettings(
builder -> builder.maxConnectionIdleTime(10, TimeUnit.MINUTES)
.minSize(5).maxSize(20))
// .applyToClusterSettings(
// builder -> builder.requiredClusterType(ClusterType.REPLICA_SET)
// .hosts(Arrays.asList(new ServerAddress("host1", 27017),
// new ServerAddress("host2", 27017)))
// .build())
.build();
return MongoClients.create(clientSettings);
}
@Override
@Nonnull
protected String getDatabaseName() {
return mongoSettings.getDb();
}
@Bean(name = MONGO_TEMPLATE_REF)
public MongoTemplate ourMongoTemplate() throws Exception {
return new MongoTemplate(ourMongoClient(), getDatabaseName());
}
}
尝试通过 taskRepository.save(task) 保存任务时 Java 最终出现 WhosebugError
java.lang.WhosebugError
at java.lang.ThreadLocal.get(ThreadLocal.java:160)
at java.util.concurrent.locks.ReentrantReadWriteLock$Sync.tryReleaseShared(ReentrantReadWriteLock.java:423)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.releaseShared(AbstractQueuedSynchronizer.java:1341)
at java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock.unlock(ReentrantReadWriteLock.java:881)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:239)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:201)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:87)
at org.springframework.data.mapping.context.MappingContext.getRequiredPersistentEntity(MappingContext.java:73)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writePropertyInternal(MappingMongoConverter.java:740)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeProperties(MappingMongoConverter.java:657)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:633)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writePropertyInternal(MappingMongoConverter.java:746)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeProperties(MappingMongoConverter.java:657)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:633)
...
在 Task class 中用 @Transient 注释路径对象 taskDir 我能够坚持任务，所以问题似乎与Java/Spring/MongoDB 无法直接处理 Path 个对象。
我的下一次尝试是在 MongoConfig class 中配置自定义转换器以在 Path 和 String 表示之间进行转换：
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter converterConfigurationAdapter) {
LOG.info("configuring converters");
converterConfigurationAdapter.registerConverter(new Converter<Path, String>() {
@Override
public String convert(@Nonnull Path path) {
return path.normalize().toAbsolutePath().toString();
}
});
converterConfigurationAdapter.registerConverter(new Converter<String, Path>() {
@Override
public Path convert(@Nonnull String path) {
return Paths.get(path);
}
});
}
尽管错误仍然存在。然后我定义了 Task 对象和 DBObject 之间的直接转换，如 guide
中所示
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter converterConfigurationAdapter) {
LOG.info("configuring converters");
converterConfigurationAdapter.registerConverter(new Converter<Task, DBObject>() {
@Override
public DBObject convert(@Nonnull Task source) {
DBObject dbObject = new BasicDBObject();
if (source.getTaskDirectory() != null) {
dbObject.put("taskDir", source.getTaskDirectory().normalize().toAbsolutePath().toString());
}
...
return dbObject;
}
});
}
我仍然在 return 中得到 WhosebugError。通过我添加的日志语句，我看到 Spring 调用了 configureConverters 方法，因此应该已经注册了自定义转换器。
为什么我仍然得到 WhosebugError？我需要如何告诉 Spring 将 Path 对象视为 Strings，同时坚持并在读取时将 String 值转换为 Path 对象又是？
更新：
我现在已经遵循 the official documentation 中给出的示例并将转换器重构为它自己的 class
import org.bson.Document;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.convert.WritingConverter;
import javax.annotation.Nonnull;
@WritingConverter
public class TaskWriteConverter implements Converter<Task, Document> {
@Override
public Document convert(@Nonnull Task source) {
Document document = new Document();
document.put("_id", source.getId());
if (source.getTaskDir() != null) {
document.put("taskDir", source.getTaskDir().normalize().toAbsolutePath().toString());
}
return document;
}
}
MongoConfig class 中的配置现在看起来像这样：
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter adapter) {
LOG.info("configuring converters");
adapter.registerConverter(new TaskWriteConverter());
adapter.registerConverter(new TaskReadConverter());
adapter.registerConverter(new Converter<Path, String>() {
@Override
public String convert(@Nonnull Path path) {
return path.normalize().toAbsolutePath().toString();
}
});
adapter.registerConverter(new Converter<String, Path>() {
@Override
public Path convert(@Nonnull String path) {
return Paths.get(path);
}
});
}
将 org.springframework.data 的日志记录级别更改为 debug 后，我在日志中看到这些转换器也被选中：
2021-09-23 14:09:20.469 [INFO ] [ main] MongoConfig configuring converters
2021-09-23 14:09:20.480 [DEBUG] [ main] CustomConversions Adding user defined converter from class com.acme.Task to class org.bson.Document as writing converter.
2021-09-23 14:09:20.480 [DEBUG] [ main] CustomConversions Adding user defined converter from class org.bson.Document to class com.acme.Task as reading converter.
2021-09-23 14:09:20.481 [DEBUG] [ main] CustomConversions Adding user defined converter from interface java.nio.file.Path to class java.lang.String as writing converter.
2021-09-23 14:09:20.481 [DEBUG] [ main] CustomConversions Adding user defined converter from class java.lang.String to interface java.nio.file.Path as reading converter.
但是，我看到大多数转换器都被添加了多次，即在应用程序点击存储库上的 save 方法之前，我实际上找到了 Adding converter from class java.lang.Character to class java.lang.String as writing converter. 的日志 4 次。由于我的自定义转换器仅在第 3 次添加，所有这些转换器都出现在日志中，我感觉它们以某种方式被覆盖，因为上次“迭代”中的日志不包括我的自定义转换器。
重现该问题的测试用例如下：
@ŚpringBootTest
@AutoConfigureMockMvc
@PropertySource("classpath:application-test.properties")
public class SomeIT {
@Autowired
private TaskRepository taskRepository;
...
@Test
public void testTaskPersistence() throws Exception {
Task task = new Task("1234", Paths.get("/home/roman"));
taskRepository.save(task);
}
...
}
测试方法仅用于调查当前的持久性问题，在正常情况下根本不应该存在，因为集成测试测试大文件的上传、预处理等。然而，由于 Spring 无法（至少看起来是这样）存储包含 Path 对象的实体，此集成测试失败。
请注意，对于简单的实体，我在使用概述的设置持久化它们时没有问题，而且我也在 dockerized MongoDB 中看到它们。
我还没有时间深入研究为什么 Spring 对 Path 对象有这样的问题，或者为什么我的自定义转换器在 CustomConversions 的最后一次迭代中突然消失了日志输出。
事实证明 mongoTemplate 的配置方式确实“覆盖”了任何指定的自定义转换器，因此 Spring 无法利用这些并将 Path 转换为String 反之亦然。
将 MongoConfig 更改为以下内容后，我终于能够使用我的自定义转换器，从而按预期持久化实体：
@Configuration
@EnableMongoRepositories(basePackages = {
"path.to.repository"
}, mongoTemplateRef = MongoConfig.MONGO_TEMPLATE_REF)
@EnableConfigurationProperties(MongoSettings.class)
public class MongoConfig extends MongoConfigurationSupport {
private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public static final String MONGO_TEMPLATE_REF = "mongoAlTemplate";
private final MongoSettings mongoSettings;
@Autowired
public MongoConfig(final MongoSettings mongoSettings) {
this.mongoSettings = mongoSettings;
}
@Bean(name = "ourMongo", destroyMethod = "close")
public MongoClient ourMongoClient() {
MongoCredential credential =
MongoCredential.createCredential(mongoSettings.getUser(),
mongoSettings.getDb(),
mongoSettings.getPassword());
MongoClientSettings clientSettings = MongoClientSettings.builder()
.readPreference(ReadPreference.primary())
// enable optimistic locking for @Version and eTag usage
.writeConcern(WriteConcern.ACKNOWLEDGED)
.credential(credential)
.applyToSocketSettings(
builder -> builder.connectTimeout(15, TimeUnit.SECONDS)
.readTimeout(1, TimeUnit.MINUTES))
.applyToConnectionPoolSettings(
builder -> builder.maxConnectionIdleTime(10, TimeUnit.MINUTES)
.minSize(5).maxSize(20))
// .applyToClusterSettings(
// builder -> builder.requiredClusterType(ClusterType.REPLICA_SET)
// .hosts(Arrays.asList(new ServerAddress("host1", 27017),
// new ServerAddress("host2", 27017)))
// .build())
.build();
LOG.info("Mongo client initialized. Connecting with user {} to DB {}",
mongoSettings.getUser(), mongoSettings.getDb());
return MongoClients.create(clientSettings);
}
@Override
@Nonnull
protected String getDatabaseName() {
return mongoSettings.getDb();
}
@Bean
public MongoDatabaseFactory ourMongoDBFactory() {
return new SimpleMongoClientDatabaseFactory(ourMongoClient(), getDatabaseName());
}
@Bean(name = MONGO_TEMPLATE_REF)
public MongoTemplate ourMongoTemplate() throws Exception {
return new MongoTemplate(ourMongoDBFactory(), mappingMongoConverter());
}
@Bean
public MappingMongoConverter mappingMongoConverter() throws Exception {
DbRefResolver dbRefResolver = new DefaultDbRefResolver(ourMongoDBFactory());
MongoCustomConversions customConversions = customConversions();
MongoMappingContext context = mongoMappingContext(customConversions);
MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, context);
// this one is actually needed otherwise the WhosebugError re-appears!
converter.setCustomConversions(customConversions);
return converter;
}
@Bean
@Override
@Nonnull
public MongoCustomConversions customConversions() {
return new MongoCustomConversions(
Arrays.asList(new PathWriteConverter(), new PathReadConverter())
);
}
}
因此，不是将 MongoClient 和数据库名称直接传递给 mongoTemplate，而是保存上述值的 MongoDatabaseFactory 对象和 MappingMongoConverter 对象作为输入传递给模板。
不幸的是，需要在mappingMongoConverter()方法中传递两次customConversion对象。如果不这样做，WhosebugError 会重新出现。
使用给定的配置，从 Path 到 String 和 String 到 Path 的转换现在是可能的，因此没有从 Task 到 Task 的自定义转换当前需要 Document，反之亦然。
在一个项目中，我使用 spring-boot-starter-data-mongodb:2.5.3，因此 spring-data-mongodb:3.2.3 并且有一个简化的实体 class，如下所示：
@Document
public class Task {
@Id
private final String id;
private final Path taskDir;
...
// constructor, getters, setters
}
使用默认 Spring Mongo允许通过其 ID 检索任务的数据库存储库。
Mongo 配置如下所示：
@Configuration
@EnableMongoRepositories(basePackages = {
"path.to.repository"
}, mongoTemplateRef = MongoConfig.MONGO_TEMPLATE_REF)
@EnableConfigurationProperties(MongoSettings.class)
public class MongoConfig extends MongoConfigurationSupport {
private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public static final String MONGO_TEMPLATE_REF = "mongoAlTemplate";
private final MongoSettings mongoSettings;
@Autowired
public MongoConfig(final MongoSettings mongoSettings) {
this.mongoSettings = mongoSettings;
}
@Bean(name = "ourMongo", destroyMethod = "close")
public MongoClient ourMongoClient() {
MongoCredential credential =
MongoCredential.createCredential(mongoSettings.getUser(),
mongoSettings.getDb(),
mongoSettings.getPassword());
MongoClientSettings clientSettings = MongoClientSettings.builder()
.readPreference(ReadPreference.primary())
// enable optimistic locking for @Version and eTag usage
.writeConcern(WriteConcern.ACKNOWLEDGED)
.credential(credential)
.applyToSocketSettings(
builder -> builder.connectTimeout(15, TimeUnit.SECONDS)
.readTimeout(1, TimeUnit.MINUTES))
.applyToConnectionPoolSettings(
builder -> builder.maxConnectionIdleTime(10, TimeUnit.MINUTES)
.minSize(5).maxSize(20))
// .applyToClusterSettings(
// builder -> builder.requiredClusterType(ClusterType.REPLICA_SET)
// .hosts(Arrays.asList(new ServerAddress("host1", 27017),
// new ServerAddress("host2", 27017)))
// .build())
.build();
return MongoClients.create(clientSettings);
}
@Override
@Nonnull
protected String getDatabaseName() {
return mongoSettings.getDb();
}
@Bean(name = MONGO_TEMPLATE_REF)
public MongoTemplate ourMongoTemplate() throws Exception {
return new MongoTemplate(ourMongoClient(), getDatabaseName());
}
}
尝试通过 taskRepository.save(task) 保存任务时 Java 最终出现 WhosebugError
java.lang.WhosebugError
at java.lang.ThreadLocal.get(ThreadLocal.java:160)
at java.util.concurrent.locks.ReentrantReadWriteLock$Sync.tryReleaseShared(ReentrantReadWriteLock.java:423)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.releaseShared(AbstractQueuedSynchronizer.java:1341)
at java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock.unlock(ReentrantReadWriteLock.java:881)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:239)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:201)
at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentEntity(AbstractMappingContext.java:87)
at org.springframework.data.mapping.context.MappingContext.getRequiredPersistentEntity(MappingContext.java:73)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writePropertyInternal(MappingMongoConverter.java:740)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeProperties(MappingMongoConverter.java:657)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:633)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writePropertyInternal(MappingMongoConverter.java:746)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeProperties(MappingMongoConverter.java:657)
at org.springframework.data.mongodb.core.convert.MappingMongoConverter.writeInternal(MappingMongoConverter.java:633)
...
在 Task class 中用 @Transient 注释路径对象 taskDir 我能够坚持任务，所以问题似乎与Java/Spring/MongoDB 无法直接处理 Path 个对象。
我的下一次尝试是在 MongoConfig class 中配置自定义转换器以在 Path 和 String 表示之间进行转换：
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter converterConfigurationAdapter) {
LOG.info("configuring converters");
converterConfigurationAdapter.registerConverter(new Converter<Path, String>() {
@Override
public String convert(@Nonnull Path path) {
return path.normalize().toAbsolutePath().toString();
}
});
converterConfigurationAdapter.registerConverter(new Converter<String, Path>() {
@Override
public Path convert(@Nonnull String path) {
return Paths.get(path);
}
});
}
尽管错误仍然存在。然后我定义了 Task 对象和 DBObject 之间的直接转换，如 guide
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter converterConfigurationAdapter) {
LOG.info("configuring converters");
converterConfigurationAdapter.registerConverter(new Converter<Task, DBObject>() {
@Override
public DBObject convert(@Nonnull Task source) {
DBObject dbObject = new BasicDBObject();
if (source.getTaskDirectory() != null) {
dbObject.put("taskDir", source.getTaskDirectory().normalize().toAbsolutePath().toString());
}
...
return dbObject;
}
});
}
我仍然在 return 中得到 WhosebugError。通过我添加的日志语句，我看到 Spring 调用了 configureConverters 方法，因此应该已经注册了自定义转换器。
为什么我仍然得到 WhosebugError？我需要如何告诉 Spring 将 Path 对象视为 Strings，同时坚持并在读取时将 String 值转换为 Path 对象又是？
更新：
我现在已经遵循 the official documentation 中给出的示例并将转换器重构为它自己的 class
import org.bson.Document;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.convert.WritingConverter;
import javax.annotation.Nonnull;
@WritingConverter
public class TaskWriteConverter implements Converter<Task, Document> {
@Override
public Document convert(@Nonnull Task source) {
Document document = new Document();
document.put("_id", source.getId());
if (source.getTaskDir() != null) {
document.put("taskDir", source.getTaskDir().normalize().toAbsolutePath().toString());
}
return document;
}
}
MongoConfig class 中的配置现在看起来像这样：
@Override
protected void configureConverters(
MongoCustomConversions.MongoConverterConfigurationAdapter adapter) {
LOG.info("configuring converters");
adapter.registerConverter(new TaskWriteConverter());
adapter.registerConverter(new TaskReadConverter());
adapter.registerConverter(new Converter<Path, String>() {
@Override
public String convert(@Nonnull Path path) {
return path.normalize().toAbsolutePath().toString();
}
});
adapter.registerConverter(new Converter<String, Path>() {
@Override
public Path convert(@Nonnull String path) {
return Paths.get(path);
}
});
}
将 org.springframework.data 的日志记录级别更改为 debug 后，我在日志中看到这些转换器也被选中：
2021-09-23 14:09:20.469 [INFO ] [ main] MongoConfig configuring converters
2021-09-23 14:09:20.480 [DEBUG] [ main] CustomConversions Adding user defined converter from class com.acme.Task to class org.bson.Document as writing converter.
2021-09-23 14:09:20.480 [DEBUG] [ main] CustomConversions Adding user defined converter from class org.bson.Document to class com.acme.Task as reading converter.
2021-09-23 14:09:20.481 [DEBUG] [ main] CustomConversions Adding user defined converter from interface java.nio.file.Path to class java.lang.String as writing converter.
2021-09-23 14:09:20.481 [DEBUG] [ main] CustomConversions Adding user defined converter from class java.lang.String to interface java.nio.file.Path as reading converter.
但是，我看到大多数转换器都被添加了多次，即在应用程序点击存储库上的 save 方法之前，我实际上找到了 Adding converter from class java.lang.Character to class java.lang.String as writing converter. 的日志 4 次。由于我的自定义转换器仅在第 3 次添加，所有这些转换器都出现在日志中，我感觉它们以某种方式被覆盖，因为上次“迭代”中的日志不包括我的自定义转换器。
重现该问题的测试用例如下：
@ŚpringBootTest
@AutoConfigureMockMvc
@PropertySource("classpath:application-test.properties")
public class SomeIT {
@Autowired
private TaskRepository taskRepository;
...
@Test
public void testTaskPersistence() throws Exception {
Task task = new Task("1234", Paths.get("/home/roman"));
taskRepository.save(task);
}
...
}
测试方法仅用于调查当前的持久性问题，在正常情况下根本不应该存在，因为集成测试测试大文件的上传、预处理等。然而，由于 Spring 无法（至少看起来是这样）存储包含 Path 对象的实体，此集成测试失败。
请注意，对于简单的实体，我在使用概述的设置持久化它们时没有问题，而且我也在 dockerized MongoDB 中看到它们。
我还没有时间深入研究为什么 Spring 对 Path 对象有这样的问题，或者为什么我的自定义转换器在 CustomConversions 的最后一次迭代中突然消失了日志输出。
事实证明 mongoTemplate 的配置方式确实“覆盖”了任何指定的自定义转换器，因此 Spring 无法利用这些并将 Path 转换为String 反之亦然。
将 MongoConfig 更改为以下内容后，我终于能够使用我的自定义转换器，从而按预期持久化实体：
@Configuration
@EnableMongoRepositories(basePackages = {
"path.to.repository"
}, mongoTemplateRef = MongoConfig.MONGO_TEMPLATE_REF)
@EnableConfigurationProperties(MongoSettings.class)
public class MongoConfig extends MongoConfigurationSupport {
private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
public static final String MONGO_TEMPLATE_REF = "mongoAlTemplate";
private final MongoSettings mongoSettings;
@Autowired
public MongoConfig(final MongoSettings mongoSettings) {
this.mongoSettings = mongoSettings;
}
@Bean(name = "ourMongo", destroyMethod = "close")
public MongoClient ourMongoClient() {
MongoCredential credential =
MongoCredential.createCredential(mongoSettings.getUser(),
mongoSettings.getDb(),
mongoSettings.getPassword());
MongoClientSettings clientSettings = MongoClientSettings.builder()
.readPreference(ReadPreference.primary())
// enable optimistic locking for @Version and eTag usage
.writeConcern(WriteConcern.ACKNOWLEDGED)
.credential(credential)
.applyToSocketSettings(
builder -> builder.connectTimeout(15, TimeUnit.SECONDS)
.readTimeout(1, TimeUnit.MINUTES))
.applyToConnectionPoolSettings(
builder -> builder.maxConnectionIdleTime(10, TimeUnit.MINUTES)
.minSize(5).maxSize(20))
// .applyToClusterSettings(
// builder -> builder.requiredClusterType(ClusterType.REPLICA_SET)
// .hosts(Arrays.asList(new ServerAddress("host1", 27017),
// new ServerAddress("host2", 27017)))
// .build())
.build();
LOG.info("Mongo client initialized. Connecting with user {} to DB {}",
mongoSettings.getUser(), mongoSettings.getDb());
return MongoClients.create(clientSettings);
}
@Override
@Nonnull
protected String getDatabaseName() {
return mongoSettings.getDb();
}
@Bean
public MongoDatabaseFactory ourMongoDBFactory() {
return new SimpleMongoClientDatabaseFactory(ourMongoClient(), getDatabaseName());
}
@Bean(name = MONGO_TEMPLATE_REF)
public MongoTemplate ourMongoTemplate() throws Exception {
return new MongoTemplate(ourMongoDBFactory(), mappingMongoConverter());
}
@Bean
public MappingMongoConverter mappingMongoConverter() throws Exception {
DbRefResolver dbRefResolver = new DefaultDbRefResolver(ourMongoDBFactory());
MongoCustomConversions customConversions = customConversions();
MongoMappingContext context = mongoMappingContext(customConversions);
MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, context);
// this one is actually needed otherwise the WhosebugError re-appears!
converter.setCustomConversions(customConversions);
return converter;
}
@Bean
@Override
@Nonnull
public MongoCustomConversions customConversions() {
return new MongoCustomConversions(
Arrays.asList(new PathWriteConverter(), new PathReadConverter())
);
}
}
因此，不是将 MongoClient 和数据库名称直接传递给 mongoTemplate，而是保存上述值的 MongoDatabaseFactory 对象和 MappingMongoConverter 对象作为输入传递给模板。
不幸的是，需要在mappingMongoConverter()方法中传递两次customConversion对象。如果不这样做，WhosebugError 会重新出现。
使用给定的配置，从 Path 到 String 和 String 到 Path 的转换现在是可能的，因此没有从 Task 到 Task 的自定义转换当前需要 Document，反之亦然。