JPA @ManyToMany Java.lang.StackOverflowError:null

JPA lazy loaded a pit great God can detour

Package Com.liuzm.controller;

Import Com.liuzm.entity.UacRole;
Import Com.liuzm.entity.UacUser;
Import Com.liuzm.service.UacUserService;
Import org.springframework.web.bind.annotation.GetMapping;
Import Org.springframework.web.bind.annotation.RestController;

Import Javax.annotation.Resource;
Import Java.util.Set;

@RestController public
class Usercontroller {

    @Resource
    private uacuserservice uacuserservice;

    @GetMapping ("/") Public
    set<uacrole> Findbyloginname () {
        Uacuser uacuser = This.uacUserService.findByLoginName ("admin");
        System.out.println (uacuser);
        set<uacrole> roles = Uacuser.getroles ();
        System.out.println (Roles.size ());
        return roles
    }
}

Package com.liuzm.entity;

Import Com.fasterxml.jackson.annotation.JsonIgnore;
Import javax.persistence.*;
Import java.io.Serializable;
Import Java.util.HashSet;

Import Java.util.Set; @Entity @Table (name = "Tbl_uac_role") public class Uacrole implements Serializable {/** * Serialversionuid: In a sentence
     This variable represents what.

    * @since JDK 1.7 * * Private static final long serialversionuid = -6263200210499558891l;

    /** * ID */@Id @GeneratedValue (strategy = generationtype.identity) Private Long ID;
    /** * Role Code */@Column (name = "Role_code") private String Rolecode; @JsonIgnore @ManyToMany @JoinTable (name = "Tbl_uac_role_user", Joincolumns = {@JoinColumn (name = "role_id"), Refere Ncedcolumnname = "id"}, Inversejoincolumns = {@JoinColumn (name = "User_ID", referencedcolumnname = "id")}) Private Se

    t<uacuser> users = new hashset<> (); Public Uacrole () {} public uacrole (Long id) {this.id = ID;
    Public Long GetId () {return id;
    public void SetId (Long id) {this.id = ID;
    Public String Getrolecode () {return rolecode;
    } public void Setrolecode (String rolecode) {this.rolecode = Rolecode;
    Public set<uacuser> Getusers () {return users;
    public void Setusers (set<uacuser> users) {this.users = users; @Override public String toString () {return "uacrole{" + "id=" + ID + "
    , rolecode= ' + rolecode + ' \ ' + ', users= ' + Users + '} '; }
}

Package com.liuzm.entity;

Import Com.fasterxml.jackson.annotation.JsonIgnore;
Import javax.persistence.*;
Import java.io.Serializable;
Import Java.util.HashSet;

Import Java.util.Set; @Entity @Table (name = "Tbl_uac_user") public class Uacuser implements Serializable {/** * Serialversionuid: In a sentence
     This variable represents what.

    * @since JDK 1.7/private static final long serialversionuid = 3439493474130693948L;

    /** * ID */@Id @GeneratedValue (strategy = generationtype.identity) Private Long ID;
    /** * Login name/@Column (name = "login_name") private String loginName;

    @ManyToMany (Mappedby = "users") @JsonIgnore private set<uacrole> roles = new hashset<> ();
                @Override public String toString () {return "uacuser{" + "id= '" + ID + ' \ "+
    ", loginname= '" + loginName + ' + ", roles=" + Roles + '} ";
   Public Uacuser () {} Public Uacuser (Long id) {this.id = ID;
    Public Long GetId () {return id;
    public void SetId (Long id) {this.id = ID;
    Public String Getloginname () {return loginName;
    } public void Setloginname (String loginName) {this.loginname = LoginName;
    Public set<uacrole> GetRoles () {return roles;
    public void Setroles (set<uacrole> roles) {this.roles = roles; }
}

Package com.liuzm.repository;

Import Com.liuzm.entity.UacUser;
Import org.springframework.data.jpa.repository.JpaRepository;


Public interface Uacuserrepository extends Jparepository<uacuser, long> {

    uacuser findbyloginname (String loginName);
}

Package com.liuzm.service;

Import Com.liuzm.entity.UacUser;

Public interface Uacuserservice {

    uacuser findbyloginname (String loginName);
}

Server:
  port:8000
  Tomcat:
    uri-encoding:utf-8
Spring:
  application:
    name:jpa-test
  JPA:
      generate-ddl:false
      show-sql:true
      hibernate:
        ddl-auto:update
      Properties:
        Hibernate:
          dialect:org.hibernate.dialect.MySQL5Dialect
  DataSource:
    driver-class-name: Com.mysql.jdbc.Driver
    Url:jdbc:mysql://localhost/test?useunicode=true&characterencoding=utf-8
    Username:root
    password:123456
logging: Level
  :
    root:info
    Org.hibernate:INFO
    Org.hibernate.type.descriptor.sql.BasicBinder:TRACE
    Org.hibernate.type.descriptor.sql.BasicExtractor: TRACE

Errors are as follows

Hibernate:select uacuser0_.id as Id1_2_, uacuser0_.login_name as login_na2_2_ from Tbl_uac_user uacuser0_ where uacuser0_
. login_name=?  2017-04-19 13:49:46.187 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicbinder:binding parameter [1]   As [VARCHAR]-[admin] 2017-04-19 13:49:46.191 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextractor : Extracted value ([id1_2_]: [BIGINT])-[222] 2017-04-19 13:49:46.195 TRACE 14504---[nio-8000-exec-1] O.h.type.descri ptor.sql.BasicExtractor:extracted value ([login_na2_2_]: [VARCHAR])-[admin] hibernate:select roles0_.user_id as US er_id2_1_0_, roles0_.role_id as role_id1_1_0_, uacrole1_.id as id1_0_1_, Uacrole1_.role_code as role_cod2_0_1_ from Tbl_u
Ac_role_user roles0_ INNER JOIN Tbl_uac_role uacrole1_ on roles0_.role_id=uacrole1_.id where roles0_.user_id=?  2017-04-19 13:49:46.208 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicbinder:binding parameter [1] As [BIGINT]-[222] 2017-04-19 13:49:46.213 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextractor:extracted value ([id1_ 0_1_]: [BIGINT])-[1234] 2017-04-19 13:49:46.213 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextract or:extracted value ([role_cod2_0_1_]: [VARCHAR])-[admin] 2017-04-19 13:49:46.214 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextractor:extracted value ([user_id2_1_0_]: [BIGINT])-[222] 2017-04-19 13:49:46.214 TR ACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextractor:extracted value ([role_id1_1_0_]: [BIGINT])- [1234] Hibernate:select users0_.role_id as role_id1_1_0_, users0_.user_id as user_id2_1_0_, uacuser1_.id as id1_2_1_, UAC User1_.login_name as login_na2_2_1_ from Tbl_uac_role_user users0_ inner join Tbl_uac_user uacuser1_ on Users0_.user_id=u
Acuser1_.id where users0_.role_id=? 2017-04-19 13:49:46.217 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicbinder:binding parAmeter [1] as [BIGINT]-[1234] 2017-04-19 13:49:46.218 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicext ractor:extracted value ([id1_2_1_]: [BIGINT])-[222] 2017-04-19 13:49:46.218 TRACE 14504---[nio-8000-exec-1] o.h.t ype.descriptor.sql.BasicExtractor:extracted value ([role_id1_1_0_]: [BIGINT])-[1234] 2017-04-19 13:49:46.218 TRACE 14504---[nio-8000-exec-1] o.h.type.descriptor.sql.basicextractor:extracted value ([user_id2_1_0_]: [BIGINT])-[222 ] 2017-04-19 13:49:46.271 ERROR 14504---[nio-8000-exec-1] o.a.c.c.c.[.[. [/]. [Dispatcherservlet]: Servlet.service () for Servlet [Dispatcherservlet] in context with path [] threw exception [Handle R Dispatch failed; Nested exception is java.lang.StackOverflowError] with root cause java.lang.StackOverflowError:null at Java.util.Abs Tractcollection.tostring (abstractcollection.java:454) ~[na:1.8.0_60] at Org.hibernate.collection.internal.PersistentSet.toString (persistentset.java:300) ~[hibernate-coRe-5.0.12.final.jar:5.0.12.final] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at java.lang.String Builder.append (stringbuilder.java:131) ~[na:1.8.0_60] at com.liuzm.entity.UacUser.toString (uacuser.java:37) ~[ Classes/:na] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at Java.lang.StringBuilder.append (String builder.java:131) ~[na:1.8.0_60] at java.util.AbstractCollection.toString (abstractcollection.java:462) ~[na:1.8.0_ At Org.hibernate.collection.internal.PersistentSet.toString (persistentset.java:300) ~[ Hibernate-core-5.0.12.final.jar:5.0.12.final] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at Java . lang. Stringbuilder.append (stringbuilder.java:131) ~[na:1.8.0_60] at com.liuzm.entity.UacRole.toString (uacrole.java:69) ~[classes/:na] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at Java.lang.StringBuilder.append (stri ngbuilder.java:131) ~[na:1.8.0_60] at Java.util.AbstractCoLlection.tostring (abstractcollection.java:462) ~[na:1.8.0_60] at Org.hibernate.collection.internal.PersistentSet.toString (persistentset.java:300) ~[ Hibernate-core-5.0.12.final.jar:5.0.12.final] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at Java . lang. Stringbuilder.append (stringbuilder.java:131) ~[na:1.8.0_60] at com.liuzm.entity.UacUser.toString (uacuser.java:37) ~[classes/:na] at java.lang.String.valueOf (string.java:2994) ~[na:1.8.0_60] at Java.lang.StringBuilder.append (stri ngbuilder<