I've created an interface:
package com.sas.dropbox.businessobjects;

//tried adding the '@' to interface
public interface Submitter {

public String getEmail();
}

and when I reference it in a business object - I get a null pointer exception when I try and generate a schema.

<example>
@Entity
public class DBFile {
private Submitter submitter;
...
</example>

So my question is - what am I doing wrong/how do you implement interfaces - and can you reference an object by them in hibernate?


<see below for exception>

Pls help or educate me.


Hibernate version:
3.0

Full stack trace of any exception that occurs:
ant schemaexport
Buildfile: build.xml

init:

compile:

dist:

schemaexport:
[java] java.lang.NullPointerException
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:172)
[java] at org.apache.tools.ant.taskdefs.Java.run(Java.java:705)
[java] at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:177)
[java] at org.apache.tools.ant.taskdefs.Java.execute(Java.java:83)
[java] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[java] at org.apache.tools.ant.Task.perform(Task.java:364)
[java] at org.apache.tools.ant.Target.execute(Target.java:341)
[java] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[java] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[java] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[java] at org.apache.tools.ant.Main.runBuild(Main.java:673)
[java] at org.apache.tools.ant.Main.startAnt(Main.java:188)
[java] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:196)
[java] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:55)
[java] Caused by: java.lang.NullPointerException
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:76)
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:76)
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:68)
[java] at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:170)
[java] at org.hibernate.cfg.Configuration.generateDropSchemaScript(Configuration.java:570)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:64)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:49)
[java] at com.sas.dropbox.hibernate.GenerateSchema.main(Unknown Source)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:585)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:193)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:130)
[java] ... 13 more
[java] --- Nested Exception ---
[java] java.lang.NullPointerException
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:76)
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:76)
[java] at org.hibernate.cfg.AnnotationConfiguration.orderHierarchy(AnnotationConfiguration.java:68)
[java] at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:170)
[java] at org.hibernate.cfg.Configuration.generateDropSchemaScript(Configuration.java:570)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:64)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:49)
[java] at com.sas.dropbox.hibernate.GenerateSchema.main(Unknown Source)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:585)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:193)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:130)
[java] at org.apache.tools.ant.taskdefs.Java.run(Java.java:705)
[java] at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:177)
[java] at org.apache.tools.ant.taskdefs.Java.execute(Java.java:83)
[java] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[java] at org.apache.tools.ant.Task.perform(Task.java:364)
[java] at org.apache.tools.ant.Target.execute(Target.java:341)
[java] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[java] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[java] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[java] at org.apache.tools.ant.Main.runBuild(Main.java:673)
[java] at org.apache.tools.ant.Main.startAnt(Main.java:188)
[java] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:196)
[java] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:55)

BUILD SUCCESSFUL
Total time: 4 seconds

Name and version of the database you are using:
mysql --version
mysql Ver 14.7 Distrib 4.1.12, for portbld-freebsd5.3 (i386) using 4.3

The generated SQL (show_sql=true):
it's set to true - but wont get that far

I don't understand you

I have 3 classes and 1 interface:

Classes:
- Account
- DBFile
- DBKey

Interface:
- Submitter


2 of the classes ( DBKey & Account ) implements the Submitter interface.

(the following is the code for the submitter interface)
<code>
public interface Submitter {
public String getEmail();
}
</code>

Now, everything compiles just fine - untill I make reference to Submitter objects in DBFile

<code in dbfile>
private Submitter submitter;
@Column(nullable=false)
public Submitter getSubmitter(){
return this.submitter;
}
public void setSubmitter( Submitter submitter ){
this.submitter = submitter;
}
</code in dbfile>

After adding the submitter reference in DBFile and running this:
AnnotationConfiguration cfg = ExampleConfiguration.getConfig();;
SchemaExport schemaExport = new SchemaExport(cfg);
schemaExport.create(true, true);

: I get the following error message ( actually - this is just one of the error messages I can manage to get )


<error message>
> ant schemaexport
Buildfile: build.xml

init:

compile:
[javac] Compiling 1 source file to /home/mike1/Desktop/MyBusinessStuff/STB Technologies LTD/code/Java/Working/DropBox/DropBox1/WEB-INF/classes

dist:
[jar] Building jar: /home/mike1/Desktop/MyBusinessStuff/STB Technologies LTD/code/Java/Working/DropBox/DropBox1/WEB-INF/lib/annotations.jar

schemaexport:
[java] org.hibernate.MappingException: Could not determine type for: com.sas.dropbox.businessobjects.Submitter, for columns: [org.hibernate.mapping.Column(submitter)]
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:172)
[java] at org.apache.tools.ant.taskdefs.Java.run(Java.java:705)
[java] at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:177)
[java] at org.apache.tools.ant.taskdefs.Java.execute(Java.java:83)
[java] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[java] at org.apache.tools.ant.Task.perform(Task.java:364)
[java] at org.apache.tools.ant.Target.execute(Target.java:341)
[java] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[java] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[java] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[java] at org.apache.tools.ant.Main.runBuild(Main.java:673)
[java] at org.apache.tools.ant.Main.startAnt(Main.java:188)
[java] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:196)
[java] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:55)
[java] Caused by: org.hibernate.MappingException: Could not determine type for: com.sas.dropbox.businessobjects.Submitter, for columns: [org.hibernate.mapping.Column(submitter)]
[java] at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:265)
[java] at org.hibernate.mapping.Column.getSqlTypeCode(Column.java:128)
[java] at org.hibernate.mapping.Column.getSqlType(Column.java:172)
[java] at org.hibernate.mapping.Table.sqlCreateString(Table.java:298)
[java] at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:645)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:65)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:49)
[java] at com.sas.dropbox.hibernate.GenerateSchema.main(Unknown Source)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:585)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:193)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:130)
[java] ... 13 more
[java] --- Nested Exception ---
[java] org.hibernate.MappingException: Could not determine type for: com.sas.dropbox.businessobjects.Submitter, for columns: [org.hibernate.mapping.Column(submitter)]
[java] at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:265)
[java] at org.hibernate.mapping.Column.getSqlTypeCode(Column.java:128)
[java] at org.hibernate.mapping.Column.getSqlType(Column.java:172)
[java] at org.hibernate.mapping.Table.sqlCreateString(Table.java:298)
[java] at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:645)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:65)
[java] at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:49)
[java] at com.sas.dropbox.hibernate.GenerateSchema.main(Unknown Source)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:585)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:193)
[java] at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:130)
[java] at org.apache.tools.ant.taskdefs.Java.run(Java.java:705)
[java] at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:177)
[java] at org.apache.tools.ant.taskdefs.Java.execute(Java.java:83)
[java] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
[java] at org.apache.tools.ant.Task.perform(Task.java:364)
[java] at org.apache.tools.ant.Target.execute(Target.java:341)
[java] at org.apache.tools.ant.Target.performTasks(Target.java:369)
[java] at org.apache.tools.ant.Project.executeTarget(Project.java:1214)
[java] at org.apache.tools.ant.Project.executeTargets(Project.java:1062)
[java] at org.apache.tools.ant.Main.runBuild(Main.java:673)
[java] at org.apache.tools.ant.Main.startAnt(Main.java:188)
[java] at org.apache.tools.ant.launch.Launcher.run(Launcher.java:196)
[java] at org.apache.tools.ant.launch.Launcher.main(Launcher.java:55)
</error msg>


Any thoughts or feedback are appriciated,

mike

1. @ManyToOne cannot be implied
2. association to unmapped Interface are not supported in hibernate, so you'll have to set targetEntity to one of the implementation.
3. mapped interface are not supported in Hibernate annotations.