来自vividsolutions JTS的几何图形在创建JSON时失败
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：
@RequestMapping(value = "/test_point", method = RequestMethod.GET, produces = "application/json;charset=UTF-8") @ResponseBody public Map 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：
{"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...
我的应用程序也抛出此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)
有什么想法有什么不对？ 提前致谢。
如果您使用的是Spring Boot，这就足够了：
pom.xml ：
com.bedatadriven jackson-datatype-jts 2.3
JacksonConfig.java ：
package org.lskk.lumen.helpdesk; import com.bedatadriven.jackson.datatype.jts.JtsModule; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration public class JacksonConfig { @Bean public JtsModule jtsModule() { return new JtsModule(); } }
这不是一个很好的解决方案，但它帮助我解决问题。
因此，问题是以Jackson的方式序列化JTS Polygon和Point对象。 此问题由项目jackson-datatype-jts解决。 您可以在github上显示此库源代码 – https://github.com/bedatadriven/jackson-datatype-jts
我需要运行我的test_point是：
1）为jackson-datatype-jts添加依赖项和存储库：
com.bedatadriven jackson-datatype-jts 1.0-SNAPSHOT sonatype-oss https://oss.sonatype.org/content/groups/public
2）以这种方式更改源代码：
@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; }
这确实有效，但我想在其他POJO中返回什么？ 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：
public class CustomMapper extends ObjectMapper { public CustomMapper() { super(); this.registerModule(new JtsModule()); } }
3）编辑spring config xml（对我来说 – servlet.xml）添加下一个字符串：
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！