My Java version is the 1.5.0 _ 14 and the value-3126998878902358585l comes from a solution that I read in a forum. The class that I'm trying to use is: Import java. util. date;Public class dateextendido extends Date { Static final long serialversionuid =-3126998878902358585l; Public date = NULL; Public dateextendido (){ Super (); } Public dateextendido (date d ){ Super (); Date = D; } } I'm using it in this lines: Try { Dateextendido iniciodesdeex = new dateextendido (iniciodesde ); Out. writeobject (iniciodesdeex ); Dateextendido iniciohastaex = new dateextendido (iniciohasta ); Out. writeobject (iniciohastaex ); } Catch (exception e ){ E. printstacktrace (system. Out ); } ... Dateextendido iniciodesdeex = NULL; Try { Iniciodesdeex = (dateextendido) in. readobject (); Iniciodesde = iniciodesdeex. date; Dateextendido iniciohastaex = (dateextendido) in. readobject (); Iniciohasta = iniciohastaex. date; } Catch (exception e ){ E. printstacktrace (system. Out ); } And the error: Java. Io. invalidclassexception: Java. util. date; local class incompatible: stream classdesc serialversionuid = 7523895402267505689, local class serialversionuid = 7523967970034938905 At java. Io. objectstreamclass. initnonproxy (unknown source) At java. Io. objectinputstream. readnonproxydesc (unknown source) At java. Io. objectinputstream. readclassdesc (unknown source) At java. Io. objectinputstream. readnonproxydesc (unknown source) At java. Io. objectinputstream. readclassdesc (unknown source) At java. Io. objectinputstream. readordinaryobject (unknown source) At java. Io. objectinputstream. readobject0 (unknown source) At java. Io. objectinputstream. readobject (unknown source) At dumbo7.user. filtrousuario. readobject (filtrousuario. Java: 348) At dumbo7.user. filtrousuario. importfiltro (filtrousuario. Java: 436) At dumbo7.user. dumbouser. setpersonaldata (dumbouser. Java: 250) At dumbo7.user. dumbouser. <init> (dumbouser. Java: 69) At dumbo7.inicio. gestorinicio. logindumbo (gestorinicio. Java: 81) At sun. Reflect. nativemethodaccessorimpl. invoke0 (native method) At sun. Reflect. nativemethodaccessorimpl. Invoke (unknown source) At sun. Reflect. delegatingmethodaccessorimpl. Invoke (unknown source) At java. Lang. Reflect. method. Invoke (unknown source) At atica. frameweb. Manager. managermodule. domethod (managermodule. Java: 611) At atica. frameweb. Manager. managermodule. doobjectdbmethod (managermodule. Java: 371) At atica. frameweb. Manager. managermodule. doobject (managermodule. Java: 261) At atica. frameweb. Manager. managermodule. doactions (managermodule. Java: 201) At atica. frameweb. Manager. httpservletmanager. Service (httpservletmanager. Java: 122) At javax. servlet. http. httpservlet. Service (httpservlet. Java: 803) At org. Apache. Catalina. servlets. invokerservlet. serverequest (invokerservlet. Java: 420) At org. Apache. Catalina. servlets. invokerservlet. doget (invokerservlet. Java: 134) At javax. servlet. http. httpservlet. Service (httpservlet. Java: 690) At javax. servlet. http. httpservlet. Service (httpservlet. Java: 803) At org. Apache. Catalina. Core. applicationfilterchain. internaldofilter (applicationfilterchain. Java: 269) At org. Apache. Catalina. Core. applicationfilterchain. dofilter (applicationfilterchain. Java: 188) At org. Apache. Catalina. Core. standardwrappervalve. Invoke (standardwrappervalve. Java: 213) At org. Apache. Catalina. Core. standardcontextvalve. Invoke (standardcontextvalve. Java: 174) At org. Apache. Catalina. Core. standardhostvalve. Invoke (standardhostvalve. Java: 127) At org. Apache. Catalina. Valves. errorreportvalve. Invoke (errorreportvalve. Java: 117) At org. Apache. Catalina. Core. standardenginevalve. Invoke (standardenginevalve. Java: 108) At org. Apache. Catalina. connector. coyoteadapter. Service (coyoteadapter. Java: 151) At org. Apache. Coyote. http11.http11processor. Process (http11processor. Java: 874) At org. Apache. Coyote. http11.http11baseprotocol $ http11connectionhandler. processconnection (http11baseprotocol. Java: 665) At org.apache.tomcat.util.net. pooltcpendpoint. processsocket (pooltcpendpoint. Java: 528) At org.apache.tomcat.util.net. leaderfollowerworkerthread. Runit (leaderfollowerworkerthread. Java: 81) At org. Apache. tomcat. util. threads. threadpool $ controlrunnable. Run (threadpool. Java: 689) At java. Lang. thread. Run (unknown source) |