I built my thymeleaf template to display some values from database in specific fields . I had two classes "Iden" and "Target" joined , each "iden" had many "target". I m trying to display those values interconnecting the two classes i got an error in my thymeleaf template ("Property or field 'ref' cannot be found on null"). Any one could help to find what happens.
<td th:text="${p.iden.ref}"></td> this is the code of iden class :
package com.example.dot.entities; import java.io.Serializable; import java.util.Date; import java.util.List; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.OneToMany; import javax.persistence.Table; import org.springframework.format.annotation.DateTimeFormat; import com.fasterxml.jackson.annotation.JsonIdentityInfo; import com.fasterxml.jackson.annotation.ObjectIdGenerators; @Entity @Table(name = "iden") @JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id_iden") public class Iden implements Serializable { /** * */ private static final long serialVersionUID = 1L; @Id @GeneratedValue private Long id_iden; @DateTimeFormat(pattern = "yyyy-MM-dd") @Column(name = "dte_deb_inter", columnDefinition="DATE") private Date dte_deb_inter; private String cse_deb_inter; private String ref ; private String dir_gen; private String dir_chg; @OneToMany(mappedBy = "iden", fetch = FetchType.LAZY) private List<Target> targets; @ManyToOne @JoinColumn(name = "CODE_ORD") public Ordre ordre; public List<Target> getTargets() { return targets; } public void setTargets(List<Target> targets) { this.targets = targets; } public Iden() { super(); // TODO Auto-generated constructor stub } public Iden(Date dte_deb_inter, String cse_deb_inter, String ref,String dir_gen,String dir_chg ,Ordre ordre) { super(); this.dte_deb_inter = dte_deb_inter; this.cse_deb_inter = cse_deb_inter; this.dir_chg =dir_chg; this.dir_gen =dir_gen; this.ref =ref; this.ordre = ordre; } public Long getId_iden() { return id_iden; } public void setId_iden(Long id_iden) { this.id_iden = id_iden; } public Date getDte_deb_inter() { return dte_deb_inter; } public void setDte_deb_inter(Date dte_deb_inter) { this.dte_deb_inter = dte_deb_inter; } public String getCse_deb_inter() { return cse_deb_inter; } public void setCse_deb_inter(String cse_deb_inter) { this.cse_deb_inter = cse_deb_inter; } public Ordre getOrdre() { return ordre; } public void setOrdre(Ordre ordre) { this.ordre = ordre; } public String getRef() { return ref; } public void setRef(String ref) { this.ref = ref; } public String getDir_gen() { return dir_gen; } public void setDir_gen(String dir_gen) { this.dir_gen = dir_gen; } public String getDir_chg() { return dir_chg; } public void setDir_chg(String dir_chg) { this.dir_chg = dir_chg; } }this is the code of target class :
package com.example.dot.entities; import java.io.Serializable; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; import org.springframework.format.annotation.DateTimeFormat; import com.fasterxml.jackson.annotation.JsonIdentityInfo; import com.fasterxml.jackson.annotation.ObjectIdGenerators; @Entity @Table(name = "target") @JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id_trg") public class Target implements Serializable{ /** * */ private static final long serialVersionUID = 1L; @Id @GeneratedValue private Long id_trg; @DateTimeFormat(pattern = "yyyy-MM-dd") @Column(name = "dte_fin_inter", columnDefinition="DATE") private Date dte_fin_inter; private String cse_fin_inter; private String acti ; private Integer flag_status; private String name ; private String type ; private Long number ; private String st; private String ope; private String por ; @ManyToOne @JoinColumn(name = "CODE_IDEN") public Iden iden; public Target() { super(); // TODO Auto-generated constructor stub } public Target(Date dte_fin_inter, String cse_fin_inter, String acti, Integer flag_status, String name, String type, Long number, String st, String por,String ope, Iden iden) { super(); this.ope = ope; this.dte_fin_inter = dte_fin_inter; this.cse_fin_inter = cse_fin_inter; this.acti = acti; this.flag_status = flag_status; this.name = name; this.type = type; this.number = number; this.st = st; this.por = por; this.iden = iden; } public Long getId_trg() { return id_trg; } public void setId_trg(Long id_trg) { this.id_trg = id_trg; } public Date getDte_fin_inter() { return dte_fin_inter; } public void setDte_fin_inter(Date dte_fin_inter) { this.dte_fin_inter = dte_fin_inter; } public String getCse_fin_inter() { return cse_fin_inter; } public void setCse_fin_inter(String cse_fin_inter) { this.cse_fin_inter = cse_fin_inter; } public String getActi() { return acti; } public void setActi(String acti) { this.acti = acti; } public Integer getFlag_status() { return flag_status; } public void setFlag_status(Integer flag_status) { this.flag_status = flag_status; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getType() { return type; } public void setType(String type) { this.type = type; } public Long getNumber() { return number; } public void setNumber(Long number) { this.number = number; } public String getSt() { return st; } public void setSt(String st) { this.st = st; } public String getpor() { return por; } public void setpor(String por) { this.por = por; } public Iden getIden() { return iden; } public void setIden(Iden iden) { this.iden = iden; } public String getOpe() { return ope; } public void setOpe(String ope) { this.ope = ope; } }this is the controller code to get the list of targets :
@Controller public class TargetController { @Autowired Targetrepository trgrepo; @RequestMapping("/alltarget") public String formall(Model model) { List<Target> listTarget =trgrepo.findAll(); model.addAttribute("list",listTarget); return "allIdentifiant"; } }and Finally the thymeleaf template :
<tbody> <tr th:each="p:${list}"> <td th:text="${p.cse_fin_inter}"></td> <td><span th:text="${p.iden.ref}" ></span> </td> <td th:text="${p.acti}"></td> <td><span th:text="${p.por}" ></span></td> <td><span th:text="${p.ope}"></span></td> <td th:text="${#dates.format(p.dte_fin_inter, 'yyyy-MM-dd')}"></td> <td><span th:text="${p.st}"></span></td> <td><span th:text="${p.number}"></span></td> <td><span th:text="${p.name}"></span></td> <td> </td> </tbody>
