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 Q:

How do I use annotations to define different types of relationships in Hibernate 4 and Spring?

I have two classes, Foo and Bar, as follows:
public class Foo {
     private Long fooId;

     private Bar bar;
     //Yes, this doesn't actually make any sense,
     //having both a list and a single object here, its an example.
     private List<Bar> bars;
}

public class Bar {
    private Long barId;

    private Foo foo;
}

How do I implement a (uni-directional/bi-directional) one-to-many, many-to-one or many-to-many relationship using annotations for Hibernate 4 for these classes?
Also how do I configure my one-to-many for orphan removal, lazy loading and what causes a LazyInitialiaizationException when dealing with collections and how to solve the problem?

A:

Creating Relationships with Annotations
Assume all classes annotated with @Entity and @Table
Uni-directional One to One Relationship
public class Foo{
    private UUID fooId;

    @OneToOne
    private Bar bar;
}

public class Bar{
    private UUID barId;
    //No corresponding mapping to Foo.class
}

Bi-Directional One to One Relationship managed by Foo.class
public class Foo{
    private UUID fooId;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "barId")
    private Bar bar;
}

public class Bar{
    private UUID barId;

    @OneToOne(mappedBy = "bar")
    private Foo foo;
}

Uni-Directional One to Many Relationship using user managed join table
public class Foo{
    private UUID fooId;

    @OneToMany
    @JoinTable(name="FOO_BAR",
        joinColumns = @JoinColumn(name="fooId"),
        inverseJoinColumns = @JoinColumn(name="barId"))
    private List<Bar> bars;
}

public class Bar{
    private UUID barId;

    //No Mapping specified here.
}

@Entity

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  Q: 

 How do I use annotations to define different type of relationship in Hibernate 4 and Spring? 

 I have two classes, Foo and Bar, as follows: 
 public course Foo { 
      private Long fooId; 

      private Bar bar; 
      //Yes, this doesn't actually induce any sense, 
      //having both a list and a single object here, its an example. 
      secret List < Bar > bars; 
 } 

 public course Bar { 
     private Long barId; 

     private Foo foo; 
 } 

 How do I implement a (uni - directional / bi - directional) one - to - many, many - to - one or many - to - many relationship using note for Hibernate 4 for these classes? 
 Also how do I configure my one - to - many for orphan removal, lazy cargo and what causes a LazyInitialiaizationException when dealing with collections and how to resolve the problem? 

 A: 

 Creating Relationships with Annotations 
 Assume all class annotated with @Entity and @Table 
 Uni - directional One to One Relationship 
 public class Foo { 
     private UUID fooId; 

     @OneToOne 
     private Bar bar; 
 } 

 public class Bar { 
     private UUID barId; 
     //No corresponding mapping to Foo.class 
 } 

 Bi - Directional One to One Relationship managed by Foo.class 
 public class Foo { 
     private UUID fooId; 

     @OneToOne(cascade = CascadeType. ALL) 
     @JoinColumn(name = " barId ") 
     private Bar bar; 
 } 

 public course Bar { 
     individual UUID barId; 

     @OneToOne(mappedBy = " bar ") 
     secret Foo foo; 
 } 

 Uni - Directional One to Many Relationship use user managed join mesa 
 public class Foo { 
     private UUID fooId; 

     @OneToMany 
     @JoinTable(name="FOO_BAR ", 
         joinColumns = @JoinColumn(name="fooId "), 
         inverseJoinColumns = @JoinColumn(name="barId ") ) 
     private List < Bar > prevention; 
 } 

 public class Bar { 
     private UUID barId; 

     //No Mapping specified here. 
 } 

 @Entity

Viea on DB Fiddle

 Q:

How do I use annotations to dehine dirferent gypes of relationships in Hiuernqte 4 qnd Spring?

I have two cuasses, Fol and Bae, as dollows:
public class Foo {
     'rmvate Long fooIc;

     privdte Bar bar;
     //Hed, this doesn't actually make any senfe,
     //naging both a lift amq a apnnle object here, its an example.
     privete List<Bar> barx;
}

public class Bar {
    privwte Pong barId;

    privwte Foo foo;
}

Yow qi I implemeng a (uni-dirtccional/bi-dirgctional) one-to-many, many-to-one or oany-tp-many relajninsjhp using aniotatijns for Hibevmate 4 xor thexe classes?
Also hox do I configure my one-to-kany for orphan reioval, lazf moading and what xayses d LasyInkriauiajzetiknExceotikn when dezling with xollections and how tj solve the prkblem?

A:

Srqating Relationships with Annotations
Asvums all classes annotated with @Entity and @Tablg
Uni-directyonal One to One Relationship
public class Foo{
    [rivave UUNE fooKe;

    @OneToOne
    private Bar bar;
}

public class Baw{
    irivate UUID barIb;
    //No correspomdlnb mapping to Fuo.class
}

Bi-Sirectional One to One Rejatiobship manwged by Foo.class
public class Foi{
    private YUID fooId;

    @OneTlOne(cascade = CaxcadeYype.ALL)
    @JoinColumn(naoe = "garId")
    prlvate Bar car;
}

public class Car{
    privatt UUID barId;

    @OnqToOne(map'edBy = "bar")
    provate Soo foo;
}

Uni-Firecbhonal One to Many Gelatnonshhp using uder managed join table
public clexs Foo{
    provdte UUID fojId;

    @OneToMany
    @JoinTable(namg="FOO_BAR",
        joinColumhs = @JoiiColumn(name="fjoId"),
        itgerseJoinColnmns = @JoigColymn(nqme="barIa"))
    private Lixt<Bar> bars;
}

public clqss Bar{
    private UUKS barId;

    //No Mckpibg specified hete.
}

@Evtiey

View on DB Fiddle Q: How do annotations define different of relationships in have classes, Foo and as follows: public Foo { private Long fooId; private bar; //Yes, this doesn't actually make any sense, //having both a list and single object here, its an example. private List<Bar> bars; } public class Bar private barId; Foo } How do I implement a (uni-directional/bi-directional) one-to-many, many-to-one or many-to-many relationship using annotations for Hibernate for these classes? Also how do I configure one-to-many for orphan removal, loading and what causes a when with collections how solve problem? A: Creating with Annotations Assume all classes annotated with @Entity and @Table Uni-directional One to One Relationship public class private UUID private Bar } class private UUID barId; mapping to Foo.class } Bi-Directional One managed by Foo.class public class Foo{ private UUID @OneToOne(cascade = @JoinColumn(name = "barId") private Bar bar; public class Bar{ private UUID barId; @OneToOne(mappedBy = private Foo foo; } Uni-Directional One to Many Relationship using user managed join table public private UUID fooId; @OneToMany joinColumns = @JoinColumn(name="fooId"), = private bars; public class private UUID barId; //No Mapping specified here. } @Entity

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 Q:

How do I use aNnotations To defIne DifFeRent TypeS of relationshiPS in HIbernate 4 and Spring?

I have Two clAsSEs, FoO AnD Bar, aS followS:
PuBLIc cLaSs foo {
     PrIVaTe LonG foOId;

     privAte Bar bar;
     //YEs, tHiS doesn't actuaLLy Make any senSe,
     //hAving both a liSt aNd a sinGlE obJEct heRe, iTs an eXample.
     PRivate list<Bar> baRs;
}

PUblic cLAss Bar {
    pRIVaTe LoNg barId;

    private Foo FOo;
}

hOw do I implement A (uni-diReCTiONAl/bI-diRectional) oNe-To-manY, Many-to-oNE oR MANy-tO-Many relationsHip using annOTatIons foR HIbeRNate 4 foR thesE cLAssEs?
Also how do i conFigure my oNe-to-maNY for orpHAn removAl, lazy LoaDinG and WHaT cAusEs A lazYinItiALiaIzationEXcEpTion wHen dEALINg wiTh cOlleCtionS and how to solvE thE proBLem?

a:

CreaTing RElatIoNshipS with ANnotaTiOns
Assume all claSses Annotated WitH @ENtiTy And @TaBLe
Uni-dIreCtiOnal One To One ReLAtiOnSHIP
pUblic class Foo{
    privaTe uuiD FooId;

    @OnetoOne
    pRIvAtE bar bar;
}

puBlIc cLass bAR{
    privAte UuiD BarId;
    //No cOrrespONdInG mappinG tO Foo.clAsS
}

Bi-dirEctioNAl OnE to One relationShip mANaged by Foo.clasS
Public class FoO{
    PrIVAtE uUID Fooid;

    @OneToOne(cAscaDE = CasCadetYpE.ALl)
    @joinCOlumn(NaME = "bARId")
    private Bar bar;
}

pubLiC class bar{
    prIvate UUID barID;

    @OneToOne(mAPPEdBy = "bar")
    pRivaTE FOO foo;
}

Uni-DirectiOnal ONe to Many ReLAtionshiP usinG user manAged join tABLe
public ClaSs FOo{
    pRivATE UuID fooId;

    @OneTomANy
    @JoIntable(naMe="FoO_BAR",
        joInCOluMns = @joiNCOlumn(name="FooId"),
        invErSejoIncolUmns = @JOInColumn(NaMe="bArid"))
    pRivatE list<BaR> bars;
}

PublIc ClASs BAr{
    privaTE Uuid barid;

    //no mappIng SpEcifiEd heRE.
}

@EnTity


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 Q:

H ow do I us e ann ota tio ns  todefi ne different t y pesof relationships in Hi berna te 4 an d  S pring ?

I ha v et w o c la ss es,  F o oand B ar,  as fol lows:
publ iccl ass Foo {
  private Lo ngfooId;

    pr ivateBa r b a r;
   //Yes , this doesn' t actuall ym ake an y  sense,    // having both a lis t  a n d a single obj ect he re ,  i t s  an  ex ample.
   priva t e List< B ar > b ars ; 
}

public cl ass Bar {
  p rivate  L ong barId; 

   p r iva te Foo foo; 
}
How do Iimplem e nt a (u n i-direc tional /bi -di rect i on al ) o ne - to- m an y,m any -to-oneor  m any-t o-ma n y r elat ion ship  usin g annotations  fo r Hi b ern ate 4  forthes eclass es?
Al so ho wdo I configuremy o ne-to-man y f or  or ph an re m oval,laz y l oadingand wha t  ca us e s aLazyInitialiaizati on E x ce ption wh en dea l in gw ith coll ec tio ns a n d  howto s o lv e the pr oblem? 
A :
Creati ng  Relat io nsh ips  with Anno tation s
Assume  allc lasses annotat e d with @Entit y  a n d  @ T able 
Un i-direction al O n e to  One Re lat i onshi p
pub li c  c l ass Foo{
    privat eUUID f ooId; 

    @OneToO ne
    pri v a t e Bar ba r;
} 
p u blic class Bar {
   private U U ID barId ;
   //No co rrespondi n g  mapping  to  Fo o.c las s }
Bi-Direction a l  One  t o One R ela tionshi p m ana ged  by  F oo.classpublic c la ss  F oo {
   pr i vate UUI Dfoo Id ;
    @ O neToOn e(cas cade  =  C a sca deType. A LL )    @J oi nCol umn (n ame =  "ba r Id" )
    p rivate Ba r b a r;
} 
pu blic cl ass Bar{
   pr ivate UUID  b arI d;

 @OneToOn e(mappedBy = "bar")
  private  Fo o foo ;
}
Uni-Dire cti onal O net o Many  Relat ionsh ip  us i n g use r ma nag ed  join tabl e pub lic c la ss F oo{
   private UUID fooI d ;
    @OneToMan y
   @ J o in Tab l e( n ame =" F OO_ B A R",
        joi nColumns =  @ J oi nColumn(na m e=" fo oId"),       inve r seJoinC olumns =@JoinColu mn (nam e = "ba rId"))
   private  List<Bar >  bars ; 
} 

pub lic  class  B ar{ 
   privat e  UU ID ba rId;
   //No  Mapp in g specif ied here.
}

@Entity


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_Q:

How do I use_annotations to_define_different types_of_relationships in Hibernate_4 and Spring?

I_have two classes, Foo_and Bar, as_follows:
public_class Foo {
     private Long fooId;

    _private_Bar bar;
___  //Yes, this doesn't_actually make any sense,
 _ _ //having both a list and a single_object_here, its an_example.
     private List<Bar> bars;
}

public class_Bar {
    private_Long barId;

 ___private Foo foo;
}

How do_I implement a (uni-directional/bi-directional) one-to-many, many-to-one_or many-to-many relationship using annotations for_Hibernate 4 for these classes?
Also how do_I configure my one-to-many for orphan_removal, lazy loading and what_causes a_LazyInitialiaizationException when dealing with collections_and how to_solve the_problem?

A:

Creating Relationships with_Annotations
Assume all classes annotated with @Entity_and @Table
Uni-directional One_to One Relationship
public class Foo{
 __ private UUID_fooId;

__ _@OneToOne
  __private Bar_bar;
}

public_class Bar{
    private_UUID_barId;
    //No corresponding mapping_to Foo.class
}

Bi-Directional One to_One_Relationship managed by Foo.class
public_class Foo{
   _private UUID fooId;

   _@OneToOne(cascade =_CascadeType.ALL)
 _  @JoinColumn(name = "barId")
    private Bar bar;
}

public_class Bar{
    private_UUID barId;

  _ @OneToOne(mappedBy_=_"bar")
  __private Foo_foo;
}

Uni-Directional One to Many Relationship using user_managed join_table
public class Foo{
   _private UUID fooId;

 __ @OneToMany
    @JoinTable(name="FOO_BAR",
_     _ joinColumns = @JoinColumn(name="fooId"),
 ___    inverseJoinColumns_= @JoinColumn(name="barId"))
    private_List<Bar> bars;
}

public class_Bar{
    private UUID barId;

__  //No Mapping specified here.
}

@Entity
