我正在为我的电报频道开发简单的机器人,并且正在使用 Java 16 功能,例如记录类。问题是我无法将传入请求反序列化到记录类中。我正在使用 Jackson 和 Micronaut 来设置客户端。这是我的课程:
用户记录
public record User(
long id,
boolean isBot,
String firstName,
String userName,
boolean canJoinGroups,
boolean canReadAllGroupMessages,
boolean supportsInlineQueries) {
}
Telegram回复记录
public record TelegramResponse<T>(T result, boolean ok) {
}
TelegramApiClient 类
@Client("https://api.telegram.org/bot${bot.id}")
public interface TelegramApiClient {
@Get("/getMe")
TelegramResponse<User> getSelf();
}
当我调用此方法时,出现此错误:
16:22:52.916 [default-nioEventLoopGroup-1-2] ERROR i.m.h.s.netty.RoutingInBoundHandler - Unexpected error occurred: Error decoding HTTP response body: Error decoding stream for type [class com.praytic.TelegramResponse]: Can not set final java.lang.Boolean field com.praytic.User.supportsInlineQueries to java.lang.Boolean (through reference chain: com.praytic.TelegramResponse["result"])
io.micronaut.http.client.exceptions.HttpClientResponseException: Error decoding HTTP response body: Error decoding stream for type [class com.praytic.TelegramResponse]: Can not set final java.lang.Boolean field com.praytic.User.supportsInlineQueries to java.lang.Boolean (through reference chain: com.praytic.TelegramResponse["result"])
at io.micronaut.http.client.netty.DefaultHttpClient$11.channelReadInstrumented(DefaultHttpClient.java:2191)
at io.micronaut.http.client.netty.DefaultHttpClient$11.channelReadInstrumented(DefaultHttpClient.java:2061)
at io.micronaut.http.client.netty.DefaultHttpClient$SimpleChannelInboundHandlerInstrumented.channelRead0(DefaultHttpClient.java:2765)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.micronaut.http.netty.stream.HttpStreamsHandler.channelRead(HttpStreamsHandler.java:194)
at io.micronaut.http.netty.stream.HttpStreamsClientHandler.channelRead(HttpStreamsClientHandler.java:183)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:436)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1368)
at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1234)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1280)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:831)
Caused by: io.micronaut.http.codec.CodecException: Error decoding stream for type [class com.praytic.TelegramResponse]: Can not set final java.lang.Boolean field com.praytic.User.supportsInlineQueries to java.lang.Boolean (through reference chain: com.praytic.TelegramResponse["result"])
at io.micronaut.jackson.codec.JacksonMediaTypeCodec.decode(JacksonMediaTypeCodec.java:209)
at io.micronaut.http.client.netty.FullNettyClientHttpResponse.convertByteBuf(FullNettyClientHttpResponse.java:280)
at io.micronaut.http.client.netty.FullNettyClientHttpResponse.lambda$getBody$1(FullNettyClientHttpResponse.java:218)
at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1224)
at io.micronaut.http.client.netty.FullNettyClientHttpResponse.getBody(FullNettyClientHttpResponse.java:192)
at io.micronaut.http.client.netty.FullNettyClientHttpResponse.<init>(FullNettyClientHttpResponse.java:111)
at io.micronaut.http.client.netty.DefaultHttpClient$11.channelReadInstrumented(DefaultHttpClient.java:2121)
... 52 common frames omitted
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not set final java.lang.Boolean field com.praytic.User.supportsInlineQueries to java.lang.Boolean (through reference chain: com.praytic.TelegramResponse["result"])
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:274)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty._throwAsIOE(SettableBeanProperty.java:623)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty._throwAsIOE(SettableBeanProperty.java:611)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty._throwAsIOE(SettableBeanProperty.java:634)
at com.fasterxml.jackson.databind.deser.impl.FieldProperty.set(FieldProperty.java:193)
at com.fasterxml.jackson.databind.deser.impl.PropertyValue$Regular.assign(PropertyValue.java:62)
at com.fasterxml.jackson.databind.deser.impl.PropertyBasedCreator.build(PropertyBasedCreator.java:211)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:520)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1405)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:362)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:195)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:542)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeWithErrorWrapping(BeanDeserializer.java:565)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:449)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1405)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:362)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:195)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:322)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4593)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3643)
at io.micronaut.jackson.codec.JacksonMediaTypeCodec.decode(JacksonMediaTypeCodec.java:204)
... 58 common frames omitted
Caused by: java.lang.IllegalAccessException: Can not set final java.lang.Boolean field com.praytic.User.supportsInlineQueries to java.lang.Boolean
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:76)
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:80)
at java.base/jdk.internal.reflect.UnsafeQualifiedObjectFieldAccessorImpl.set(UnsafeQualifiedObjectFieldAccessorImpl.java:79)
at java.base/java.lang.reflect.Field.set(Field.java:793)
at com.fasterxml.jackson.databind.deser.impl.FieldProperty.set(FieldProperty.java:190)
... 74 common frames omitted
我从this文章中读到Jackson 2.12已经支持
java.lang.Record
类型。我的 Micronaut Jackson 配置:
jackson:
property-naming-strategy: SNAKE_CASE
serialization-inclusion: always
编辑:
正如我所猜测的,在记录标题中的每个字段上添加
@JsonProperty
注释是有效的。例外已经消失,所有价值观都受到欢迎。
public record User(
long id,
@JsonProperty("is_bot") boolean isBot,
@JsonProperty("first_name") String firstName,
@JsonProperty("user_name") String userName,
@JsonProperty("can_join_groups") boolean canJoinGroups,
@JsonProperty("can_read_all_group_messages") boolean canReadAllGroupMessages,
@JsonProperty("supports_inline_queries") boolean supportsInlineQueries) {
}
但是,我不想对我的每条 DTO 记录都执行此操作。如何让
jackson.property-naming-strategy: SNAKE_CASE
财产发挥作用?
有2种解决方案:
public class RecordNamingStrategyPatchModule extends SimpleModule {
@Override
public void setupModule(SetupContext context) {
context.addValueInstantiators(new ValueInstantiatorsModifier());
super.setupModule(context);
}
/**
* Remove when the following issue is resolved:
* <a href="https://github.com/FasterXML/jackson-databind/issues/2992">Properties naming strategy do not work with Record #2992</a>
*/
private static class ValueInstantiatorsModifier extends ValueInstantiators.Base {
@Override
public ValueInstantiator findValueInstantiator(
DeserializationConfig config, BeanDescription beanDesc, ValueInstantiator defaultInstantiator
) {
if (!beanDesc.getBeanClass().isRecord() || !(defaultInstantiator instanceof StdValueInstantiator) || !defaultInstantiator.canCreateFromObjectWith()) {
return defaultInstantiator;
}
Map<String, BeanPropertyDefinition> map = beanDesc.findProperties().stream().collect(Collectors.toMap(p -> p.getInternalName(), Function.identity()));
SettableBeanProperty[] renamedConstructorArgs = Arrays.stream(defaultInstantiator.getFromObjectArguments(config))
.map(p -> {
BeanPropertyDefinition prop = map.get(p.getName());
return prop != null ? p.withName(prop.getFullName()) : p;
})
.toArray(SettableBeanProperty[]::new);
return new PatchedValueInstantiator((StdValueInstantiator) defaultInstantiator, renamedConstructorArgs);
}
}
private static class PatchedValueInstantiator extends StdValueInstantiator {
protected PatchedValueInstantiator(StdValueInstantiator src, SettableBeanProperty[] constructorArguments) {
super(src);
_constructorArguments = constructorArguments;
}
}
}
您可以使用
将模块添加到 ObjectMapperobjectMapper.registerModule(new RecordNamingStrategyPatchModule());
如果我理解正确的话,问题不是序列化,而是反序列化。对于反序列化,Jackson 需要读取构造函数中每个参数的名称,以将字段从 JSON 正确映射到 Java。
自动执行此操作的一种方法(无需 @JsonProperty 注释)是从 jackson-module-parameter-names jar 添加 ParameterNamesModule:
mapper.registerModule(new ParameterNamesModule());
这还要求使用 -parameters 编译标志来编译类(至少对于 java 8 - 11)。在 Maven 中,您可以通过以下方式执行此操作:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<compilerArgs>
<arg>-parameters</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
但是,我从未使用 Java 16 对此进行过测试,所以请告诉我它是否也适用于 Java 16。
对我有用的解决方案(Jackson 2.13.x)是向记录类添加规范构造函数并使用
@JsonCreator
:
record Thing(
String one,
String two,
Boolean someFlag
) {
public Thing(String one, String two) {
this(one, two, null);
}
@JsonCreator
public Thing(
String one,
String two,
@JsonProperty("some_flag") Boolean someFlag
) {
this.one = one;
this.two = two;
this.someFlag = Objects.requireNonNullElse(someFlag, true);
}
}