java - MyBatis ManyToOne & OneToMany mapping -

i use java 7 , mybatis 3.2.2. problem following. have 3 classes - a, b, c.

a has list of b, b has list of c. - 1 many

c has set b, b has set a. - many one

 /*   * java classes   */    public class {       private int id;       private list<b> blist;       ...    }    public class b {       private int id;       private a;       private list<c> clist;       ...    }     public class c {       private int id;       private b b;       ...    }     /*     * mybatis result maps     */   <resultmap id="amap" type="a">   <id     property="id"      column="a_id" />   <collection property="list" column="b_id" oftype="b" resultmap="bmap"/>  </resultmap>   <resultmap id="bmap" type="b">   <id     property="id"      column="b_id" />   <association property="a"  column="a_id" resultmap="amap"/>   <collection property="list" column="c_id" oftype="c" resultmap="cmap"/>  </resultmap>   <resultmap id="cmap" type="c">   <id     property="id"      column="c_id" />   <association property="b"  column="b_id" resultmap="bmap"/>   </resultmap>     /*     * mybatis select     */  <select id="get..."  resultmap="xmap">  select     a.id a_id,     b.id b_id,     c.id c_id  a  left join b b on a.id = b.ida  left join c c on b.id = c.idb </select> 

/* * problem */

when resultmap xmap = amap correct. objects created , populate properly

when resultmap xmap = cmap error bellow thrown.

when amap removed collection of bs - correct. - wierd, looks mybatis can map depth??

this issue complicates work in sense of reusability of mybatis elements. off course can create result maps broke reusability principles.

any idea how solve this?

/* * error - mybatis throws following exception: */

org.mybatis.spring.mybatissystemexception: nested exception org.apache.ibatis.reflection.reflectionexception: not set property 'blist' of 'a' value 'b [id=1]' cause: java.lang.illegalargumentexception: argument type mismatch     @ org.mybatis.spring.mybatisexceptiontranslator.translateexceptionifpossible(mybatisexceptiontranslator.java:73)     @ org.mybatis.spring.sqlsessiontemplate$sqlsessioninterceptor.invoke(sqlsessiontemplate.java:364)     @ com.sun.proxy.$proxy23.selectlist(unknown source)     @ org.mybatis.spring.sqlsessiontemplate.selectlist(sqlsessiontemplate.java:194)     @ org.apache.ibatis.binding.mappermethod.executeformany(mappermethod.java:114)     @ org.apache.ibatis.binding.mappermethod.execute(mappermethod.java:58)     @ org.apache.ibatis.binding.mapperproxy.invoke(mapperproxy.java:43)     @ com.sun.proxy.$proxy45.getkeywordsbynoderesult(unknown source)     @ xtest.testgetkeywordsbynoderesult(workflowmappertest.java:35)     @ sun.reflect.nativemethodaccessorimpl.invoke0(native method)     @ sun.reflect.nativemethodaccessorimpl.invoke(nativemethodaccessorimpl.java:62)     @ sun.reflect.delegatingmethodaccessorimpl.invoke(delegatingmethodaccessorimpl.java:43)     @ java.lang.reflect.method.invoke(method.java:498)     @ org.junit.runners.model.frameworkmethod$1.runreflectivecall(frameworkmethod.java:47)     @ org.junit.internal.runners.model.reflectivecallable.run(reflectivecallable.java:12)     @ org.junit.runners.model.frameworkmethod.invokeexplosively(frameworkmethod.java:44)     @ org.junit.internal.runners.statements.invokemethod.evaluate(invokemethod.java:17)     @ org.springframework.test.context.junit4.statements.runbeforetestmethodcallbacks.evaluate(runbeforetestmethodcallbacks.java:72)     @ org.springframework.test.context.junit4.statements.runaftertestmethodcallbacks.evaluate(runaftertestmethodcallbacks.java:81)     @ org.springframework.test.context.junit4.statements.springrepeat.evaluate(springrepeat.java:72)     @ org.junit.runners.parentrunner.runleaf(parentrunner.java:271)     @ org.springframework.test.context.junit4.springjunit4classrunner.runchild(springjunit4classrunner.java:216)     @ org.springframework.test.context.junit4.springjunit4classrunner.runchild(springjunit4classrunner.java:82)     @ org.junit.runners.parentrunner$3.run(parentrunner.java:238)     @ org.junit.runners.parentrunner$1.schedule(parentrunner.java:63)     @ org.junit.runners.parentrunner.runchildren(parentrunner.java:236)     @ org.junit.runners.parentrunner.access$000(parentrunner.java:53)     @ org.junit.runners.parentrunner$2.evaluate(parentrunner.java:229)     @ org.springframework.test.context.junit4.statements.runbeforetestclasscallbacks.evaluate(runbeforetestclasscallbacks.java:60)     @ org.springframework.test.context.junit4.statements.runaftertestclasscallbacks.evaluate(runaftertestclasscallbacks.java:67)     @ org.junit.runners.parentrunner.run(parentrunner.java:309)     @ org.springframework.test.context.junit4.springjunit4classrunner.run(springjunit4classrunner.java:162)     @ org.eclipse.jdt.internal.junit4.runner.junit4testreference.run(junit4testreference.java:86)     @ org.eclipse.jdt.internal.junit.runner.testexecution.run(testexecution.java:38)     @ org.eclipse.jdt.internal.junit.runner.remotetestrunner.runtests(remotetestrunner.java:459)     @ org.eclipse.jdt.internal.junit.runner.remotetestrunner.runtests(remotetestrunner.java:675)     @ org.eclipse.jdt.internal.junit.runner.remotetestrunner.run(remotetestrunner.java:382)     @ org.eclipse.jdt.internal.junit.runner.remotetestrunner.main(remotetestrunner.java:192) 

.....

you don´t need mybatis this. can define list of childs parent tracking way:

public abstract class listwithparenttracking<child> extends arraylist<child> {      @override     public boolean add(child c)     {         this.setparent(c);         return super.add(c);     }      protected abstract void trackparent(child c);  }; 

then define class as:

public class {   private int id;   private final list<b> blist;   ...   public a()   {      final me = this;      this.blist = new listwithparenttracking<b>()      {         @override         protected void trackparent(b b)         {            b.seta(me);         }       }   } }  

and let own objects magic.