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问Spring引导页反序列化- PageImpl无构造函数
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Stack Overflow用户

提问于 2018-09-25 04:01:37

回答 9查看 30.4K关注 0票数 22

尝试从spring引导接收页面的单元测试。如果与javascript一起使用，页面可以很容易地反序列化，但如果使用java，则会失败。已经为spring添加了一个默认构造函数(在另一个堆栈溢出帖子中是一个可接受的答案)，但是它在这里不起作用。

单元测试

@Test
public void test_read_pagination_happy(@Autowired ObservationSet set) {

    repository.save(set);

    final HttpEntity<String> authHeaders = authentication.convert("", authSuccess);
    final ParameterizedTypeReference<RestResponsePage<ObservationSet>> responseType = new ParameterizedTypeReference<RestResponsePage<ObservationSet>>() {
    };
    // final ResponseEntity<String> result = restTemplate.exchange(base + "/api/v1/observationset", HttpMethod.GET, authHeaders, String.class);
    final ResponseEntity<RestResponsePage<ObservationSet>> result = restTemplate.exchange(base + "/api/v1/observationset", HttpMethod.GET, authHeaders,
                    responseType);
    System.out.println(result.getBody());
    assertSame(HttpStatus.OK, result.getStatusCode(), "incorrect status code");
}

RestRespongePage类

class RestResponsePage<T> extends PageImpl<T> {

    private static final long serialVersionUID = 3248189030448292002L;

    public RestResponsePage(List<T> content, Pageable pageable, long total) {
        super(content, pageable, total);
    }

    public RestResponsePage(List<T> content) {
        super(content);
    }

    public RestResponsePage() {
        super(new ArrayList<T>());
    }

}

Code is available on github --> [https://github.com/OpenPCM/openpcm-server/blob/integration-test/src/test/java/org/openpcm/controller/ObservationSetControllerIntTest.java](https://github.com/OpenPCM/openpcm-server/blob/integration-test/src/test/java/org/openpcm/controller/ObservationSetControllerIntTest.java)

The deserialization throws this error:

```javascript

org.springframework.http.converter.HttpMessageConversionException:类型定义错误:简单类型，类org.springframework.data.domain.Pageable；嵌套的异常是com.fasterxml.jackson.databind.exc.InvalidDefinitionException:不能构造org.springframework.data.domain.Pageable的实例(没有创建者，像默认构造一样，存在)：抽象类型要么需要映射到具体类型，要么需要自定义反序列化器，或者包含额外的类型信息。

在Source: (PushbackInputStream); line: 1, column: 294

at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:240)

at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:225)

at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:100)

at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:959)

at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:942)

at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:689)

at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:644)

at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:593)

at org.springframework.boot.test.web.client.TestRestTemplate.exchange(TestRestTemplate.java:843)

at org.openpcm.controller.ObservationSetControllerIntTest.test_read_pagination_happy(ObservationSetControllerIntTest.java:85)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:564)

at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:436)

at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)

at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:170)

at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)

at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:166)

at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:113)

at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:58)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:112)

at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)

at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)

at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)

at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)

at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)

at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)

at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)

at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)

at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)

at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)

at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:430)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)

at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)

at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)

at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)

at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)

at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)

at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)

at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)

at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)

at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)

at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)

at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:430)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)

at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:55)

at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)

at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)

at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)

at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)

at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)

由: com.fasterxml.jackson.databind.exc.InvalidDefinitionException:无法构造org.springframework.data.domain.Pageable实例(没有创建者，与默认构造一样，存在)：抽象类型需要映射到具体类型、具有自定义反序列化程序或包含其他类型信息。

在Source: (PushbackInputStream); line: 1, column: 294

at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:67)

at com.fasterxml.jackson.databind.DeserializationContext.reportBadDefinition(DeserializationContext.java:1451)

at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1027)

at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserialize(AbstractDeserializer.java:265)

at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:136)

at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)

at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)

at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4013)

at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3084)

at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:237)

... 65 more

spring-boot

pagination

deserialization

java

spring

回答 9

Stack Overflow用户

发布于 2019-02-17 05:22:03

有一种更简单的方法--为Page接口创建和注册自定义反序列化器。因此，使用将是简单明了的：

//Catalog is the paged entity
Page<Catalog> page = objectMapper.readValue(content, new TypeReference<Page<Catalog>>() {});

ObjectMapper配置：

ObjectMapper objectMapper= new ObjectMapper();
objectMapper.registerModule(new PageModule());

PageModule：

public class PageModule extends SimpleModule {
    private static final long serialVersionUID = 1L;

    public PageModule() {
        addDeserializer(Page.class, new PageDeserializer());
    }
}

PageDeserializer：

public class PageDeserializer extends JsonDeserializer<Page<?>> implements ContextualDeserializer {
    private static final String CONTENT = "content";
    private static final String NUMBER = "number";
    private static final String SIZE = "size";
    private static final String TOTAL_ELEMENTS = "totalElements";
    private JavaType valueType;

    @Override
    public Page<?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        final CollectionType valuesListType = ctxt.getTypeFactory().constructCollectionType(List.class, valueType);

        List<?> list = new ArrayList<>();
        int pageNumber = 0;
        int pageSize = 0;
        long total = 0;
        if (p.isExpectedStartObjectToken()) {
            p.nextToken();
            if (p.hasTokenId(JsonTokenId.ID_FIELD_NAME)) {
                String propName = p.getCurrentName();
                do {
                    p.nextToken();
                    switch (propName) {
                        case CONTENT:
                            list = ctxt.readValue(p, valuesListType);
                            break;
                        case NUMBER:
                            pageNumber = ctxt.readValue(p, Integer.class);
                            break;
                        case SIZE:
                            pageSize = ctxt.readValue(p, Integer.class);
                            break;
                        case TOTAL_ELEMENTS:
                            total = ctxt.readValue(p, Long.class);
                            break;
                        default:
                            p.skipChildren();
                            break;
                    }
                } while (((propName = p.nextFieldName())) != null);
            } else {
                ctxt.handleUnexpectedToken(handledType(), p);
            }
        } else {
            ctxt.handleUnexpectedToken(handledType(), p);
        }

        //Note that Sort field of Page is ignored here.
        //Feel free to add more switch cases above to deserialize it as well.  
        return new PageImpl<>(list, PageRequest.of(pageNumber, pageSize), total);
    }

    /**
     * This is the main point here.
     * The PageDeserializer is created for each specific deserialization with concrete generic parameter type of Page.
     */
    @Override
    public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanProperty property) {
        //This is the Page actually
        final JavaType wrapperType = ctxt.getContextualType();
        final PageDeserializer deserializer = new PageDeserializer();
        //This is the parameter of Page
        deserializer.valueType = wrapperType.containedType(0);
        return deserializer;
    }
}

票数 11

Stack Overflow用户

发布于 2020-10-06 23:11:55

这起作用了，(org.springframework.cloud:spring-cloud-openfeign-core:2.2.5.RELEASE)：

@Configuration
public class FeignConfigurationFactory {

    @Bean
    public Module pageJacksonModule() {
        return new PageJacksonModule();
    }

    @Bean
    public Module sortJacksonModule() {
        return new SortJacksonModule();
    }
}

票数 11

Stack Overflow用户

发布于 2019-01-29 14:47:22

不得不做一个小小的改变来忽略未知属性的空：

package ...helper;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.JsonNode;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;

import java.util.ArrayList;
import java.util.List;

@JsonIgnoreProperties(ignoreUnknown = true)
public class RestResponsePage<T> extends PageImpl<T> {
    @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
    public RestResponsePage(@JsonProperty("content") List<T> content,
                            @JsonProperty("number") int number,
                            @JsonProperty("size") int size,
                            @JsonProperty("totalElements") Long totalElements,
                            @JsonProperty("pageable") JsonNode pageable,
                            @JsonProperty("last") boolean last,
                            @JsonProperty("totalPages") int totalPages,
                            @JsonProperty("sort") JsonNode sort,
                            @JsonProperty("first") boolean first,
                            @JsonProperty("numberOfElements") int numberOfElements) {

        super(content, PageRequest.of(number, size), totalElements);
    }

    public RestResponsePage(List<T> content, Pageable pageable, long total) {
        super(content, pageable, total);
    }

    public RestResponsePage(List<T> content) {
        super(content);
    }

    public RestResponsePage() {
        super(new ArrayList<>());
    }
}

票数 6

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/52490399

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