Jackson Mapper 返回 null spring rest
Jackson Mapper returning null with spring rest
我从这个 link
得到 Json
我正在使用以下两个 pojo 类 进行映射。
1)NewsSource.class
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "status", "sources" })
public class NewsSource {
@JsonProperty("status")
private String status;
@JsonProperty("sources")
private List<Source> sources = null;
@JsonProperty("status")
public String getStatus() {
return status;
}
@JsonProperty("status")
public void setStatus(String status) {
this.status = status;
}
@JsonProperty("sources")
public List<Source> getSources() {
return sources;
}
@JsonProperty("sources")
public void setSources(List<Source> sources) {
this.sources = sources;
}
}
2)Source.class
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "id", "name", "description", "url", "category", "language", "country", "sortBysAvailable" })
public class Source {
@JsonProperty("id")
private String id;
@JsonProperty("name")
private String name;
@JsonProperty("description")
private String description;
@JsonProperty("url")
private String url;
@JsonProperty("category")
private String category;
@JsonProperty("language")
private String language;
@JsonProperty("country")
private String country;
@JsonProperty("sortBysAvailable")
private List<String> sortBysAvailable = null;
//getter setters generated with IDE , and annotated with @JsonProperty too
我正在使用此代码将 json 映射到 pojo 。
public NewsSource getNewsSource() {
String URL = source_url; //above mentioned url to get json
ObjectMapper omapper= new ObjectMapper();
omapper.setVisibilityChecker(omapper.getSerializationConfig().getDefaultVisibilityChecker()
.withFieldVisibility(JsonAutoDetect.Visibility.ANY)
.withGetterVisibility(JsonAutoDetect.Visibility.NONE)
.withSetterVisibility(JsonAutoDetect.Visibility.NONE)
.withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
NewsSource newsSource =null;
try {
String result = restTemplate.getForObject(URL, String.class);
//result is returnning data properly
omapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
newsSource = omapper.readValue(result, NewsSource.class);
//newsSource returnning null
}catch (Exception ex){
System.out.println("oooh exception ");
}
我尝试了 this link 中提到的许多建议技巧，但没有一个对我有用:)
注意：我正在为 Jackson 使用以下 maven 依赖项。
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
如有任何建议，我们将不胜感激。提前致谢
更新
我使用了以下代码。
private static Object getJsonObject(String str) {
Object obj = null;
try {
ObjectMapper mapper = new ObjectMapper();
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
if (str != null) {
obj = mapper.readValue(str, NewsSource.class);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("json obj:===>" + obj);
return obj;
}
public NewsSource getNewsSource() {
String URL = source_url;
NewsSource newsSource =null;
try {
String result = restTemplate.getForObject(URL, String.class);
//String jsonStr=getJsonString(result);
ObjectMapper mapper = new ObjectMapper();
// newsSource = mapper.readValue(result, NewsSource.class);
newsSource= (NewsSource) getJsonObject(result);
System.out.println("done:" +newsSource);
}catch (Exception ex){
System.out.println("oooh exception ");
}
return newsSource;
}
StackTrace
com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of VALUE_STRING token
at [Source: {"status":"ok","sources":[{"id":"abc-news-au","name":"ABC News (AU)","description":"Australia's most trusted source of local, national and world news. Comprehensive, independent, in-depth analysis, the latest business, sport, weather and more.","url":"http://www.abc.net.au/news","category":"general","language":"en","country":"au","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"al-jazeera-english","name":"Al Jazeera English","description":"News, analysis from the Middle East and worldwide, multimedia and interactives, opinions, documentaries, podcasts, long reads and broadcast schedule.","url":"http://www.aljazeera.com","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"ars-technica","name":"Ars Technica","description":"The PC enthusiast's resource. Power users and the tools they love, without computing religion.","url":"http://arstechnica.com","category":"technology","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"associated-press","name":"Associated Press","description":"The AP delivers in-depth coverage on the international, politics, lifestyle, business, and entertainment news.","url":"https://apnews.com/","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"bbc-news","name":"BBC News","description":"Use BBC News for up-to-the-minute news, breaking news, video, audio and feature stories. BBC News provides trusted World and UK news as well as local and regional perspectives. Also entertainment, business, science, technology and health news.","url":"http://www.bbc.co.uk/news","category":"general","language":"en","country":"gb","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"bbc-sport","name":"BBC Sport","description":"The home of BBC Sport online. Includes live sports coverage, breaking news, results, video, audio and analysis on Football, F1, Cricket, Rugby Union, Rugby League, Golf, Tennis and all the main world sports, plus major events such as the Olympic Games.","url":"http://www.bbc.co.uk/sport","category":"sport","language":"en","country":"gb","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"time","name":"Time","description":"Breaking news and analysis from TIME.com. Politics, world news, photos, video, tech reviews, health, science and entertainment news.","url":"http://time.com","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"usa-today","name":"USA Today","description":"Get the latest national, international, and political news at USATODAY.com.","url":"http://www.usatoday.com/news","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"}]}; line: 1, column: 402] (through reference chain: com.example.demo.dto.NewsSource["sources"]->java.util.ArrayList[0]->com.example.demo.dto.Source["sortBysAvailable"])
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
at com.fasterxml.jackson.databind.DeserializationContext.reportMappingException(DeserializationContext.java:1234)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1122)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1075)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.handleNonArray(StringCollectionDeserializer.java:260)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:187)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:20)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:504)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:104)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:276)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:140)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:287)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:259)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:26)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:504)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:104)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:276)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:140)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3814)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2858)
at com.example.demo.Utill.RuleUtill.getJsonObject(RuleUtill.java:80)
at com.example.demo.Utill.RuleUtill.getNewsSource(RuleUtill.java:100)
at com.example.demo.Service.NewsApiService.getSource(NewsApiService.java:32)
at com.example.demo.Controller.Home.somespecific(Home.java:56)
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 org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
json obj:===>null
done:null
代码运行正常。看起来您使用的是旧版本的杰克逊。我使用 2.9.0 进行了测试，下面的代码按预期工作，尽管 2.9.0 版本 setVisibilityChecker(.....) 已被弃用。
public static void main(String[] args) {
NewsSource nSource=new NewsSource();
nSource.setStatus("status");
Source source=new Source();
source.setCategory("category");
List<Source> sList=new ArrayList<Source>();
sList.add(source);
nSource.setSources(sList);
String jsonStr=getJsonString(nSource);
//{"status":"status","sources":[{"category":"category"}]}
System.out.println(jsonStr);
NewsSource newsSource =(NewsSource)getJsonObject(jsonStr);
//NewsSource@1810399e
System.out.println(newsSource);
}
private static String getJsonString(Object object) {
String jsonString = "";
try {
ObjectMapper mapper = new ObjectMapper();
if (object != null) {
jsonString = mapper.writeValueAsString(object);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("jsonString:===>" + jsonString);
return jsonString;
}
private static Object getJsonObject(String str) {
Object obj = null;
try {
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibilityChecker(mapper.getSerializationConfig().getDefaultVisibilityChecker()
.withFieldVisibility(JsonAutoDetect.Visibility.ANY)
.withGetterVisibility(JsonAutoDetect.Visibility.NONE)
.withSetterVisibility(JsonAutoDetect.Visibility.NONE)
.withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
if (str != null) {
obj = mapper.readValue(str, NewsSource.class);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("json obj:===>" + obj);
return obj;
}
由于某些原因，我修改了你的源代码如下：
- RestTemplete 会自动将响应 Json 字符串转换为您在
NewsSource 和 Source. 中定义的指定 POJO
- 正如我上面所说，方法
getJsonObject是多余的。
- 您在方法
getNewsSource 中的异常处理没有打印出真正的原因。
getNewsSource
public NewsSource getNewsSource() {
String URL = source_url;
NewsSource newsSource =null;
try {
/*
String result = restTemplate.getForObject(URL, String.class);
ObjectMapper mapper = new ObjectMapper();
newsSource= (NewsSource) getJsonObject(result);
System.out.println("done:" +newsSource);
*/
newsSource = restTemplate.getForObject(URL, NewsSource.class);
System.out.println("done:" + newsSource.toString());
} catch (Exception ex){
System.out.println("oooh exception \n" + ex);
}
return newsSource;
}
希望对您有所帮助！ :)
我从这个 link
得到 Json我正在使用以下两个 pojo 类 进行映射。
1)NewsSource.class
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "status", "sources" })
public class NewsSource {
@JsonProperty("status")
private String status;
@JsonProperty("sources")
private List<Source> sources = null;
@JsonProperty("status")
public String getStatus() {
return status;
}
@JsonProperty("status")
public void setStatus(String status) {
this.status = status;
}
@JsonProperty("sources")
public List<Source> getSources() {
return sources;
}
@JsonProperty("sources")
public void setSources(List<Source> sources) {
this.sources = sources;
}
}
2)Source.class
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "id", "name", "description", "url", "category", "language", "country", "sortBysAvailable" })
public class Source {
@JsonProperty("id")
private String id;
@JsonProperty("name")
private String name;
@JsonProperty("description")
private String description;
@JsonProperty("url")
private String url;
@JsonProperty("category")
private String category;
@JsonProperty("language")
private String language;
@JsonProperty("country")
private String country;
@JsonProperty("sortBysAvailable")
private List<String> sortBysAvailable = null;
//getter setters generated with IDE , and annotated with @JsonProperty too
我正在使用此代码将 json 映射到 pojo 。
public NewsSource getNewsSource() {
String URL = source_url; //above mentioned url to get json
ObjectMapper omapper= new ObjectMapper();
omapper.setVisibilityChecker(omapper.getSerializationConfig().getDefaultVisibilityChecker()
.withFieldVisibility(JsonAutoDetect.Visibility.ANY)
.withGetterVisibility(JsonAutoDetect.Visibility.NONE)
.withSetterVisibility(JsonAutoDetect.Visibility.NONE)
.withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
NewsSource newsSource =null;
try {
String result = restTemplate.getForObject(URL, String.class);
//result is returnning data properly
omapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
newsSource = omapper.readValue(result, NewsSource.class);
//newsSource returnning null
}catch (Exception ex){
System.out.println("oooh exception ");
}
我尝试了 this link 中提到的许多建议技巧，但没有一个对我有用:)
注意：我正在为 Jackson 使用以下 maven 依赖项。
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
如有任何建议，我们将不胜感激。提前致谢
更新 我使用了以下代码。
private static Object getJsonObject(String str) {
Object obj = null;
try {
ObjectMapper mapper = new ObjectMapper();
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
if (str != null) {
obj = mapper.readValue(str, NewsSource.class);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("json obj:===>" + obj);
return obj;
}
public NewsSource getNewsSource() {
String URL = source_url;
NewsSource newsSource =null;
try {
String result = restTemplate.getForObject(URL, String.class);
//String jsonStr=getJsonString(result);
ObjectMapper mapper = new ObjectMapper();
// newsSource = mapper.readValue(result, NewsSource.class);
newsSource= (NewsSource) getJsonObject(result);
System.out.println("done:" +newsSource);
}catch (Exception ex){
System.out.println("oooh exception ");
}
return newsSource;
}
StackTrace
com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of VALUE_STRING token
at [Source: {"status":"ok","sources":[{"id":"abc-news-au","name":"ABC News (AU)","description":"Australia's most trusted source of local, national and world news. Comprehensive, independent, in-depth analysis, the latest business, sport, weather and more.","url":"http://www.abc.net.au/news","category":"general","language":"en","country":"au","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"al-jazeera-english","name":"Al Jazeera English","description":"News, analysis from the Middle East and worldwide, multimedia and interactives, opinions, documentaries, podcasts, long reads and broadcast schedule.","url":"http://www.aljazeera.com","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"ars-technica","name":"Ars Technica","description":"The PC enthusiast's resource. Power users and the tools they love, without computing religion.","url":"http://arstechnica.com","category":"technology","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"associated-press","name":"Associated Press","description":"The AP delivers in-depth coverage on the international, politics, lifestyle, business, and entertainment news.","url":"https://apnews.com/","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"bbc-news","name":"BBC News","description":"Use BBC News for up-to-the-minute news, breaking news, video, audio and feature stories. BBC News provides trusted World and UK news as well as local and regional perspectives. Also entertainment, business, science, technology and health news.","url":"http://www.bbc.co.uk/news","category":"general","language":"en","country":"gb","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"bbc-sport","name":"BBC Sport","description":"The home of BBC Sport online. Includes live sports coverage, breaking news, results, video, audio and analysis on Football, F1, Cricket, Rugby Union, Rugby League, Golf, Tennis and all the main world sports, plus major events such as the Olympic Games.","url":"http://www.bbc.co.uk/sport","category":"sport","language":"en","country":"gb","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"time","name":"Time","description":"Breaking news and analysis from TIME.com. Politics, world news, photos, video, tech reviews, health, science and entertainment news.","url":"http://time.com","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"},{"id":"usa-today","name":"USA Today","description":"Get the latest national, international, and political news at USATODAY.com.","url":"http://www.usatoday.com/news","category":"general","language":"en","country":"us","urlsToLogos":{"small":"","medium":"","large":""},"sortBysAvailable":"top"}]}; line: 1, column: 402] (through reference chain: com.example.demo.dto.NewsSource["sources"]->java.util.ArrayList[0]->com.example.demo.dto.Source["sortBysAvailable"])
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
at com.fasterxml.jackson.databind.DeserializationContext.reportMappingException(DeserializationContext.java:1234)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1122)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1075)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.handleNonArray(StringCollectionDeserializer.java:260)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:187)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer.deserialize(StringCollectionDeserializer.java:20)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:504)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:104)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:276)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:140)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:287)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:259)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:26)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:504)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:104)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:276)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:140)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3814)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2858)
at com.example.demo.Utill.RuleUtill.getJsonObject(RuleUtill.java:80)
at com.example.demo.Utill.RuleUtill.getNewsSource(RuleUtill.java:100)
at com.example.demo.Service.NewsApiService.getSource(NewsApiService.java:32)
at com.example.demo.Controller.Home.somespecific(Home.java:56)
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 org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
json obj:===>null
done:null
代码运行正常。看起来您使用的是旧版本的杰克逊。我使用 2.9.0 进行了测试，下面的代码按预期工作，尽管 2.9.0 版本 setVisibilityChecker(.....) 已被弃用。
public static void main(String[] args) {
NewsSource nSource=new NewsSource();
nSource.setStatus("status");
Source source=new Source();
source.setCategory("category");
List<Source> sList=new ArrayList<Source>();
sList.add(source);
nSource.setSources(sList);
String jsonStr=getJsonString(nSource);
//{"status":"status","sources":[{"category":"category"}]}
System.out.println(jsonStr);
NewsSource newsSource =(NewsSource)getJsonObject(jsonStr);
//NewsSource@1810399e
System.out.println(newsSource);
}
private static String getJsonString(Object object) {
String jsonString = "";
try {
ObjectMapper mapper = new ObjectMapper();
if (object != null) {
jsonString = mapper.writeValueAsString(object);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("jsonString:===>" + jsonString);
return jsonString;
}
private static Object getJsonObject(String str) {
Object obj = null;
try {
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibilityChecker(mapper.getSerializationConfig().getDefaultVisibilityChecker()
.withFieldVisibility(JsonAutoDetect.Visibility.ANY)
.withGetterVisibility(JsonAutoDetect.Visibility.NONE)
.withSetterVisibility(JsonAutoDetect.Visibility.NONE)
.withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
if (str != null) {
obj = mapper.readValue(str, NewsSource.class);
}
} catch (Exception exc) {
exc.printStackTrace();
}
System.out.println("json obj:===>" + obj);
return obj;
}
由于某些原因，我修改了你的源代码如下：
- RestTemplete 会自动将响应 Json 字符串转换为您在
NewsSource和Source. 中定义的指定 POJO
- 正如我上面所说，方法
getJsonObject是多余的。 - 您在方法
getNewsSource中的异常处理没有打印出真正的原因。
getNewsSource
public NewsSource getNewsSource() {
String URL = source_url;
NewsSource newsSource =null;
try {
/*
String result = restTemplate.getForObject(URL, String.class);
ObjectMapper mapper = new ObjectMapper();
newsSource= (NewsSource) getJsonObject(result);
System.out.println("done:" +newsSource);
*/
newsSource = restTemplate.getForObject(URL, NewsSource.class);
System.out.println("done:" + newsSource.toString());
} catch (Exception ex){
System.out.println("oooh exception \n" + ex);
}
return newsSource;
}
希望对您有所帮助！ :)