java - Invalid content was found starting with element 'Element'. One of 'Element' is expected -

i'm using java's jaxb parser marshal , unmarshal xml files specific class. unmarshaling works fine, however, chokes on marshaling file following error:

cvc-complex-type.2.4.a: invalid content found starting element 'datapath'. 1 of '{"http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd":datapath}' expected.

i don't understand why wouldn't work, cause unmarshaling file works fine.

as requested, here mcve:

projectrepository.java:

package com.flyingwhales;  import org.xml.sax.saxexception;  import javax.xml.xmlconstants; import javax.xml.bind.jaxbcontext; import javax.xml.bind.jaxbexception; import javax.xml.bind.marshaller; import javax.xml.bind.unmarshaller; import javax.xml.transform.source; import javax.xml.transform.stream.streamsource; import javax.xml.validation.schema; import javax.xml.validation.schemafactory; import javax.xml.validation.validator; import java.io.file; import java.io.ioexception;  /**  * created jesse on 11/13/2016.  */  public final class projectrepository {     private static validator validator;     private static marshaller marshaller;     private static unmarshaller unmarshaller;      // class not meant instantiated.     private projectrepository() {}      static {         file schemafile = new file("project.xsd");         schemafactory schemafactory = schemafactory                 .newinstance(xmlconstants.w3c_xml_schema_ns_uri);          try {             schema schema = schemafactory.newschema(schemafile);             validator = schema.newvalidator();              // initialize jaxb stuff too.             jaxbcontext jaxbcontext = jaxbcontext.newinstance(project.class);             marshaller = jaxbcontext.createmarshaller();             marshaller.setproperty(marshaller.jaxb_formatted_output, true);             marshaller.setschema(schema);             unmarshaller = jaxbcontext.createunmarshaller();         } catch (saxexception | jaxbexception e) {             e.printstacktrace();         }     }      public static project load(file file) throws exception {         if (!validate(file)) {             throw new exception("project file contains invalid markup");         }          project project = (project)unmarshaller.unmarshal(file);         project.setprojectfile(file);          return project;     }      public static void save(project project, file path) throws jaxbexception {         marshaller.marshal(project, path);     }      public static boolean validate(file file) throws ioexception {         source source = new streamsource(file);          try {             validator.validate(source);         } catch (saxexception e) {             return false;         }          return true;     } } 

project.java

package com.flyingwhales;  import javax.xml.bind.annotation.xmlattribute; import javax.xml.bind.annotation.xmlelement; import javax.xml.bind.annotation.xmlrootelement; import java.io.file;  @xmlrootelement(name = "project") public class project {     private string name = "project";     private string type = "standalone";     private string datapath = "data";     private string scriptpath = "data/scripts";     private string artpath = "art";     private string sfxpath = "sound/sfx";     private string bgmpath = "sound/bgm";      private file projectfile;      public project() { }      public project(file file) {         setprojectfile(file);     }      @xmlattribute( name = "name" )     public string getname() {         return name;     }      public void setname(string name) {         this.name = name;     }      @xmlattribute (name = "type" )     public string gettype() {         return type;     }      public void settype(string type) {         this.type = type;     }      @xmlelement(name = "datapath")     public string getdatapath() {         return datapath;     }      public void setdatapath(string datapath) {         this.datapath = datapath;     }      @xmlelement (name = "scriptpath")     public string getscriptpath() {         return scriptpath;     }      public void setscriptpath(string scriptpath) {         this.scriptpath = scriptpath;     }      @xmlelement (name = "artpath")     public string getartpath() {         return artpath;     }      public void setartpath(string artpath) {         this.artpath = artpath;     }      @xmlelement (name = "sfxpath")     public string getsfxpath() {         return sfxpath;     }      public void setsfxpath(string sfxpath) {         this.sfxpath = sfxpath;     }      @xmlelement (name = "bgmpath")     public string getbgmpath() {         return bgmpath;     }      public void setbgmpath(string bgmpath) {         this.bgmpath = bgmpath;     }      void setprojectfile(file file) {         projectfile = file;     }      public file getprojectfile() {         return projectfile;     } } 

package-info.java

@xmlschema(namespace = "http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd") package com.flyingwhales;  import javax.xml.bind.annotation.xmlschema; 

main.java

    package com.flyingwhales;  import javax.xml.bind.jaxbexception; import java.io.file;  public class main {     public static void main(string[] args) {         // open , parse file filesystem.         try {             project loadedproject = projectrepository.load(new file("test.cinnabar"));             system.out.print("loaded project: " + loadedproject.getname());         } catch (exception e) {             e.printstacktrace();         }          // try create project , save hard drive.         project newproject = new project(new file("new.cinnabar"));          try {             projectrepository.save(newproject, new file("new.cinnabar"));         } catch (jaxbexception e) {             e.printstacktrace();         }     } } 

project.xsd

<?xml version="1.0" encoding="utf-8" ?> <xs:schema xmlns:xs="http://www.w3.org/2001/xmlschema"            targetnamespace="http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd"            xmlns="http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd"            elementformdefault="qualified">      <xs:element name="project">         <xs:complextype>             <xs:sequence>                 <xs:element name="datapath" type="xs:string" />                 <xs:element name="scriptpath" type="xs:string" />                 <xs:element name="artpath" type="xs:string" />                 <xs:element name="sfxpath" type="xs:string" />                 <xs:element name="bgmpath" type="xs:string" />             </xs:sequence>              <xs:attribute name="name" type="xs:string" use="required" />             <xs:attribute name="type" type="xs:string" use="required" />         </xs:complextype>     </xs:element> </xs:schema> 

test.cinnabar

<?xml version="1.0" encoding="utf-8"?> <project name="test project" type="standalone"          xmlns="http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd"          xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"          xsi:schemalocation="http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd">      <datapath>data</datapath>     <scriptpath>data/scripts</scriptpath>     <artpath>art</artpath>     <sfxpath>sound/sfx</sfxpath>     <bgmpath>sound/bgm</bgmpath> </project> 

simply run code , produce error. make sure project.xsd in working directory.

two things:

• your package-info.java missing elementformdefault = javax.xml.bind.annotation.xmlnsform.qualified
• as @sahoora correctly noticed, need proporder correct ordering of elements when marshalling.

package-info.java:

@xmlschema(namespace = "http://hg.flyingwhales.nl/cinnabar/schemas/project.xsd", elementformdefault = javax.xml.bind.annotation.xmlnsform.qualified) package com.flyingwhales;  import javax.xml.bind.annotation.xmlschema; 

project.java:

@xmlrootelement(name = "project") @xmltype(name = "", proporder = {         "datapath",         "scriptpath",         "artpath",         "sfxpath",         "bgmpath"     }) public class project { ... } 

the core of problem missing elementformdefault=qualified. lead local elements marshalled in empty namespace therefore schema validation , subsequent unmarshalling failed.