本文介绍了来自vividsolutions JTS的几何图形在创建JSON时失败的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
好朋友。我在我的应用程序中使用了vividsolutions的库JTS（1.13）for Points and Polygons，但是当我尝试将几何对象转换为JSON时，我的应用程序失败了。有我的来源：
pals. I'm using vividsolutions's library JTS (1.13) for Points and Polygons in my application, but when I try to convert geometry objects into JSON, my application fails. There is my source:
@RequestMapping(value = "/test_point", method = RequestMethod.GET, produces = "application/json;charset=UTF-8")
@ResponseBody
public Map<String, Object> testPoint() {
Point point = geometryFactory.createPoint(new Coordinate(37.73, 60.45));
return RequestMapBuilder.getInstance()
.addAttribute("point", point)
.build();
}
还有我收到的JSON：
And there is JSON I recieved by client:
{"point":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope":{"envelope": AND SO ON...
此外，我的应用程序抛出此异常：
Also my application throws this exception:
java.lang.IllegalStateException: Cannot call sendError() after the response has been committed
at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:478)
at javax.servlet.http.HttpServletResponseWrapper.sendError(HttpServletResponseWrapper.java:129)
at javax.servlet.http.HttpServletResponseWrapper.sendError(HttpServletResponseWrapper.java:129)
at org.springframework.security.web.context.SaveContextOnUpdateOrErrorResponseWrapper.sendError(SaveContextOnUpdateOrErrorResponseWrapper.java:92)
at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.sendServerError(DefaultHandlerExceptionResolver.java:313)
at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleHttpMessageNotWritable(DefaultHandlerExceptionResolver.java:370)
at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.doResolveException(DefaultHandlerExceptionResolver.java:140)
at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:138)
at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1183)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1020)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:149)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:168)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:205)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)
任何想法有什么问题？在此先感谢。
Any ideas what is wrong? Thanks in advance.
推荐答案
这不是一个很好的解决方案，但它可以帮助我解决问题。
This is not very nice solution, but it helps me to solve issue.
因此，问题是用Jackson的方式来序列化JTS Polygon和Point对象。此问题由项目jackson-datatype-jts解决。您可以在github上显示此库源 -
So, issue is in Jackson way to serialize JTS Polygon and Point objects. This issue is solved by project jackson-datatype-jts. You can show this library sources on github - https://github.com/bedatadriven/jackson-datatype-jts
我需要运行的test_point是：
All I need to run my test_point is:
1）添加依赖项和存储库对于jackson-datatype-jts：
1) Add dependency and repository for jackson-datatype-jts:
<dependencies>
<dependency>
<groupId>com.bedatadriven</groupId>
<artifactId>jackson-datatype-jts</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
</dependencies>
<repositories>
<repository>
<id>sonatype-oss</id>
<url>https://oss.sonatype.org/content/groups/public</url>
</repository>
</repositories>
2）以这种方式更改源代码：
2) Change source code this way:
@RequestMapping(value = "/test_point", method = RequestMethod.GET, produces = "application/json;charset=UTF-8")
@ResponseBody
public Point testPoint() {
Point point =geometryFactory.createPoint(new Coordinate(37.77, 60.01));
String result = "";
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JtsModule());
try {
result = objectMapper.writeValueAsString(point);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
return point;
}
这真的有效，但我想在其他方面回报什么POJO？有Spring Framework的解决方案：
1）重复上一节中的步骤1
2）创建一个扩展ObjectMapper类的类：
And this really works, but what is I want to return point in my other POJO? There is solution for Spring Framework:1) Repeat step 1 from previous section2) Create a class extending ObjectMapper Class:
public class CustomMapper extends ObjectMapper {
public CustomMapper() {
super();
this.registerModule(new JtsModule());
}
}
3）编辑你的spring config xml（对我来说 - servlet.xml）添加下一个字符串：
3) Edit your spring config xml (for me - servlet.xml) add next strings:
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
<bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper" ref="jacksonObjectMapper" />
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<bean id="jacksonObjectMapper" class="ru.trollsmedjan.web.dao.CustomMapper"/>
现在，您的ObjectMapper实例将替换为您的自定义对象映射器实现。它有效！
Now your ObjectMapper instance is substituted with your Custom Object mapper realization. An it works!
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