java后台树形结构展示---懒加载

一、数据库设计

二、实体类：entity

import com.joyoung.cloud.security.common.validatedGroup.Add;
import com.joyoung.cloud.security.common.validatedGroup.Modify;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.experimental.Accessors;

import javax.persistence.Id;
import javax.persistence.Transient;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Null;
import javax.validation.constraints.Pattern;
import java.io.Serializable;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

/**

• 公司表(SysCompany)实体类

• @author yangyuwei

• @since 2019-06-06 13:45:23
  */
  @ApiModel(value = “公司类”)
  @Data
  @Accessors(chain = true)
  public class SysCompany implements Serializable {

  private static final long serialVersionUID = 600959061181555399L;

  @ApiModelProperty(value = “主键Id”)
  @Id
  @Null(message = “{add_id}”, groups = {Add.class})
  @NotNull(message = “{modify_id}”, groups = {Modify.class})
  private String id;

  //上级公司id
  @ApiModelProperty(value = “父Id”)
  private String parentId;

  //公司名称
  @ApiModelProperty(value = “公司名称”)
  @NotBlank(message = “{name_null}”)
  @Pattern(regexp = “¹{1,20}$”, message = “{name_rule}”)
  private String coName;

  //公司简称
  @ApiModelProperty(value = “公司简称”)
  private String coAbbr;

  //公司编号
  @ApiModelProperty(value = “公司编号”)
  private String coCode;

  //公司地址
  @ApiModelProperty(value = “公司地址”)
  private String coAddr;

  //邮编
  @ApiModelProperty(value = “邮编”)
  @Pattern(regexp = “^$|[0-9]{6}$∣[0−9]6”, message = “{zipCode_error}”)
  private String zipCode;

  //法人名称
  @ApiModelProperty(value = “法人名称”)
  private String legalName;

  //法定代表人
  @ApiModelProperty(value = “法定代表人”)
  private String legalRep;

  //税号
  @ApiModelProperty(value = “税号”)
  private String taxId;

  //电话号码(“XXX-XXXXXXX”、“XXXX-XXXXXXXX”、“XXX-XXXXXXX”、“XXX-XXXXXXXX”、"XXXXXXX"和"XXXXXXXX)
  //
  @Pattern(regexp = “^(\(\d{3,4}\)|\d{3,4}-|\s)?\d{7,14}$”, message = “请输入正确的电话号码”)
  @ApiModelProperty(value = “电话号码”)
  private String tel;

  //开户银行名称
  @ApiModelProperty(value =“开户银行名称”)
  private String bankName;

  //开户银行账号
  @ApiModelProperty(value = “开户银行账号”)
  private String bankAcct;

  //创建人id
  private String crtUser;

  //创建人名称
  private String crtName;

  //创建时间
  private Date crtTime;

  //最后修改人id
  private String updUser;

  //最后修改人名称
  private String updName;

  //最后修改时间
  private Date updTime;

  //备注
  private String remark;

  //逻辑删除标识：1=删除；0=未删除
  private Integer delFlag;

  private String attr1;

  private String attr2;

  private String attr3;

  /以下为添加字段****/
  @Transient
  private Boolean hasChecked;
  @Transient
  private Boolean hasChildren;
  @Transient
  private List children = new LinkedList();

}

三、controller

@ApiOperation(value = “懒加载查询列表”)
@GetMapping("/children")
public List getChildren(SysCompany sysCompany) {
return service.getChildren(sysCompany);
}

四、service

@Override
public List getChildren(SysCompany sysCompany) {
List companyList = dao.selectCompanyInfo(sysCompany);
if (StringUtils.isNotBlank(sysCompany.getCoName())) {
return getTree(sysCompany);
}
return companyList;
}

/**
这里一般将此方法放在entity里面
*/

private List getTree(SysCompany sysCompany) {
Map<String, SysCompany> map = dao.selectByCompany(sysCompany);
List tree = new ArrayList<>();
map.forEach((id, obj) -> {
if (map.containsKey(obj.getParentId())) {
map.get(obj.getParentId()).getChildren().add(obj);
} else {
tree.add(obj);
}
});
return tree;
}

五、dao

public List selectCompanyInfo(SysCompany sysCompany);

六、mapper

c.id, c.parent_id, c.co_name, c.co_abbr, c.co_code, c.co_addr, c.zip_code, c.legal_name, c.legal_rep, c.tax_id, c.tel, c.bank_name, c.bank_acct, c.crt_user, c.crt_name, c.crt_time, c.upd_user, c.upd_name, c.upd_time, c.remark, c.del_flag SELECT ,EXISTS (SELECT 1 from sys_company sc where sc.parent_id=c.id and sc.del_flag=0) as hasChildren FROM sys_company c WHERE c.del_flag = 0 and c.co_name like concat ('%',#{coName},'%') and c.parent_id = #{parentId} and c.parent_id is null

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