JdbcTemplate+PageImpl实现多表分页查询

一、基础实体　

@MappedSuperclass
public abstract class AbsIdEntity implements Serializable {private static final long serialVersionUID = 7988377299341530426L;public final static int IS_DELETE_YES = 1;// 标记删除public final static int IS_DELETE_NO = 0;// 未删除,保留的
@Id@GenericGenerator(name="uuid", strategy="uuid")@GeneratedValue(generator="uuid")protected String id;@Column(name = "creationtime")protected Timestamp creationTimestamp = new Timestamp(System.currentTimeMillis());@Column(name = "lastmodifiedtime")protected Timestamp modificationTimestamp;@Column(name = "dr")protected int dr;// 是否删除。0:未删除;1:已删除/*** 主键，对应id字段*/public String getId() { return id; }public void setId(String id) { this.id = id; }/*** 创建日期，对应ts_insert字段*/public Timestamp getCreationTimestamp() { return creationTimestamp; }public void setCreationTimestamp(Timestamp creationTimestamp) { this.creationTimestamp = creationTimestamp; }/*** 修改日期，对应ts_update字段*/public Timestamp getModificationTimestamp() { return modificationTimestamp; }public void setModificationTimestamp(Timestamp modificationTimestamp) { this.modificationTimestamp = modificationTimestamp; }/*** 是否删除，对应dr字段* @return*/public int getDr() {return dr;}public void setDr(int dr) {this.dr = dr;}}
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二、扩展VO

import java.io.Serializable;
import java.sql.Date;
import java.sql.ResultSet;
import java.sql.SQLException;import org.springframework.jdbc.core.RowMapper;import xxx.entity.AbsIdEntity;public class StaffUnionVO extends AbsIdEntity implements Serializable, RowMapper<StaffUnionVO>{/*** */private static final long serialVersionUID = -5213225066818183479L;private String code;// 员工编码private String name;// 员工姓名private int sex; // 性别private Date birthday;// 出生年月日private String deptId;// 人员所属部门private String companyId;//人员所属公司表private EnumStatus status;// 员工状态，在职，离职private String nativePlace;// 籍贯private String education;// 学历private EnumPoliticalStatus politicalStatus;// 政治面貌private String major;// 所学专业private String school;// 毕业学校private Date graduationTime;// 毕业时间private Date workTime;// 参加工作时间private String credentialCode;// 证件号码private String mobile;// 移动电话private String signPic;// 签名图片private String landlineNum;// 座机号private String age;// 年龄private String post;// 职位  private String positionId;// 岗位Idprivate String dept;// 部门private String email;// 邮箱private String  userId;// 用户关联人员private int  isUser;// 是否关联人员private int credentialType;//证件类型private String address;//地址private String staffTypeId;//人员idprivate String property;//直属或隶属public String getProperty() {return property;}public void setProperty(String property) {this.property = property;}public String getPositionId() {return positionId;}public void setPositionId(String positionId) {this.positionId = positionId;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public String getStaffTypeId() {return staffTypeId;}public void setStaffTypeId(String staffTypeId) {this.staffTypeId = staffTypeId;}public int getCredentialType() {return credentialType;}public void setCredentialType(int credentialType) {this.credentialType = credentialType;}public int getIsUser() {return isUser;}public void setIsUser(int isUser) {this.isUser = isUser;}public String getUserId() {return userId;}public void setUserId(String userId) {this.userId = userId;}public String getLandlineNum() {return landlineNum;}public void setLandlineNum(String landlineNum) {this.landlineNum = landlineNum;}public String getDeptId() {return deptId;}public void setDeptId(String deptId) {this.deptId = deptId;}public String getCompanyId() {return companyId;}public void setCompanyId(String companyId) {this.companyId = companyId;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public String getPost() {return post;}public void setPost(String post) {this.post = post;}public String getPosition() {return positionId;}public void setPosition(String position) {this.positionId = position;}public String getDept() {return dept;}public void setDept(String dept) {this.dept = dept;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Date getBirthday() {return birthday;}public int getSex() {return sex;}public void setSex(int sex) {this.sex = sex;}public void setBirthday(Date birthday) {this.birthday = birthday;}public EnumStatus getStatus() {return status;}public void setStatus(EnumStatus status) {this.status = status;}public String getNativePlace() {return nativePlace;}public void setNativePlace(String nativePlace) {this.nativePlace = nativePlace;}public String getEducation() {return education;}public void setEducation(String education) {this.education = education;}public EnumPoliticalStatus getPoliticalStatus() {return politicalStatus;}public void setPoliticalStatus(EnumPoliticalStatus politicalStatus) {this.politicalStatus = politicalStatus;}public String getMajor() {return major;}public void setMajor(String major) {this.major = major;}public String getSchool() {return school;}public void setSchool(String school) {this.school = school;}public Date getGraduationTime() {return graduationTime;}public void setGraduationTime(Date graduationTime) {this.graduationTime = graduationTime;}public Date getWorkTime() {return workTime;}public void setWorkTime(Date workTime) {this.workTime = workTime;}public String getCredentialCode() {return credentialCode;}public void setCredentialCode(String credentialCode) {this.credentialCode = credentialCode;}public String getMobile() {return mobile;}public void setMobile(String mobile) {this.mobile = mobile;}public String getSignPic() {return signPic;}public void setSignPic(String signPic) {this.signPic = signPic;}@Overridepublic StaffUnionVO mapRow(ResultSet rs, int row) throws SQLException {StaffUnionVO vo = new StaffUnionVO();vo.setAddress(rs.getString("address"));vo.setAge(rs.getString("age"));vo.setBirthday(rs.getDate("birthday"));vo.setCode(rs.getString("code"));vo.setCompanyId(rs.getString("companyId"));vo.setCreationTimestamp(rs.getTimestamp("creationtime"));vo.setCredentialCode(rs.getString("credentialCode"));vo.setCredentialType(rs.getInt("credentialType"));vo.setDept(rs.getString("dept"));vo.setDeptId(rs.getString("deptId"));vo.setDr(rs.getInt("dr"));vo.setEducation(rs.getString("education"));vo.setEmail(rs.getString("email"));vo.setGraduationTime(rs.getDate("graduationTime"));vo.setId(rs.getString("id"));vo.setIsUser(rs.getInt("isUser"));vo.setLandlineNum(rs.getString("landlineNum"));vo.setMajor(rs.getString("major"));vo.setMobile(rs.getString("mobile"));vo.setModificationTimestamp(rs.getTimestamp("lastmodifiedtime"));vo.setName(rs.getString("name"));vo.setNativePlace(rs.getString("nativePlace"));vo.setPoliticalStatus(rs.getString("politicalStatus") == null || "".equals(rs.getString("politicalStatus").trim()) ? null : EnumPoliticalStatus.valueOf(rs.getString("politicalStatus")));vo.setPositionId(rs.getString("positionId"));vo.setPost(rs.getString("post"));vo.setProperty(rs.getString("property"));vo.setSchool(rs.getString("school"));vo.setSex(rs.getInt("sex"));vo.setSignPic(rs.getString("signPic"));vo.setStaffTypeId(rs.getString("staffTypeId"));vo.setStatus(rs.getString("status") == null || "".equals(rs.getString("status").trim()) ? null : EnumStatus.valueOf(rs.getString("status")));vo.setUserId(rs.getString("userId"));vo.setWorkTime(rs.getDate("workTime"));return vo;}
}
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三、使用JdbcTemplate 进行联表查询操作

@Repository
public class StaffUnionDao {@Autowiredprivate JdbcTemplate jdbcTemplate;public List<StaffUnionVO> getStaffUnion(String deptId, String param) {
　　　　 //sql中联表查询，自定义列名String sql = "select bs.id id, bs.creationtime creationtime, bs.lastmodifiedtime lastmodifiedtime, bs.dr dr, bs.code code, bs.name name, bs.sex sex, bs.birthday birthday, bsp.dept_id as deptId, bsp.company_id companyId,"+ "bs.status status, bs.native_place nativePlace, bs.education education, bs.political_status politicalStatus, bs.major major, bs.school school, bs.graduation_time graduationTime, bs.work_time workTime,"+ "bs.credential_code credentialCode, bs.mobilephone_num mobile, bs.sign_pic signPic, bs.landline_num landlineNum, bs.age age, bs.post post, bsp.position positionId, bs.dept dept, bs.is_user isUser,"+ "bs.email email, bs.userid userId, bs.credential_type credentialType, bs.address address, bs.staff_type_id staffTypeId, bsp.property property from bd_staff bs, bd_staff_partjob bsp where bs.id = bsp.staff_id and bsp.dr = 0";//String sqlx = "select bs.id id from bd_staff bs, bd_staff_partjob bsp where bs.id = bsp.staff_id and bsp.dr = 0";if(deptId != null) {sql += "and bsp.dept_id = " + deptId;}if(param != null) {sql += " and (bs.code like %" + param + "% or bs.name like %" + param + "%)";}
　　　　　(1)//该方法无法实现类中变量是对象时的转换，例如存在枚举对象。//List<StaffUnionVO> result = jdbcTemplate.query(sql, BeanPropertyRowMapper.newInstance(StaffUnionVO.class));(2)
//        可以自定义转化
//        @SuppressWarnings("unchecked")
//        List<StaffUnionVO> result = jdbcTemplate.query(sqlx,  new RowMapper() {  
//              @Override  
//              public Object mapRow(ResultSet rs, int n)  throws SQLException {  
//                  StaffUnionVO vo = new StaffUnionVO();
//                  vo.setId(rs.getString("id"));
//                  return vo;  
//              }
//        });(3)//自定义映射方式的实现写在了 StaffUnionVO类中List<StaffUnionVO> result = jdbcTemplate.query(sql, new StaffUnionVO());return result;}
}

四、使用PageImpl进行分页

　　@Autowiredprivate StaffUnionDao newPageDao;@RequestMapping(path = "newpage", method = RequestMethod.GET)@ResponseBodypublic PageImpl<StaffUnionVO> getStaffInfoNew(@RequestParam(value = "deptId", required = false) String deptId,@RequestParam(value = "searchText", required = false) String param,@RequestParam("pageNumber") int pageNumber, @RequestParam("pageSize") int pageSize) {List<StaffUnionVO> content = newPageDao.getStaffUnion(deptId, param);PageRequest pageRequest = new PageRequest(pageNumber - 1, pageSize);PageImpl<StaffUnionVO> ans = new PageImpl<StaffUnionVO>(content, pageRequest, content == null ? 0 : content.size());return ans;}

 

五、补充一种场景

　　进行分页查询的时候一般多是针对一个实体（对应一个表），通常使用的spring data jpa 的接口 JpaSpecificationExecutor<T>, 接口内容如下。

JpaSpecificationExecutor

public interface JpaSpecificationExecutor<T> {/*** Returns a single entity matching the given {@link Specification}.* * @param spec* @return*/T findOne(Specification<T> spec);/*** Returns all entities matching the given {@link Specification}.* * @param spec* @return*/List<T> findAll(Specification<T> spec);/*** Returns a {@link Page} of entities matching the given {@link Specification}.* * @param spec* @param pageable* @return*/Page<T> findAll(Specification<T> spec, Pageable pageable);/*** Returns all entities matching the given {@link Specification} and {@link Sort}.* * @param spec* @param sort* @return*/List<T> findAll(Specification<T> spec, Sort sort);/*** Returns the number of instances that the given {@link Specification} will return.* * @param spec the {@link Specification} to count instances for* @return the number of instances*/long count(Specification<T> spec);
}

　　分页查询的结果是实体类的集合，通常在服务层完成。但是我们一般不让业务层直接接触我们的实体类，所以就是产生了VO类，也就是服务层不再返回实体类的集合，而是返回VO类的集合，业务层操作的其实是VO类。这样就显得层次清晰，方便控制。例如分页查询，具体实现如下。

　　请参考：　后台json格式设计 PagableResponse（分页json格式）  ，生成查询Specification  QueryTool工具

 

Controller

　　@Autowiredprivate RoleService roleService;@RequestMapping(path = "page")@ResponseBodypublic PagableResponse<RoleVO> getPageableRole(@RequestParam(value = "roleId", required = false) String roleId,@RequestParam(value = "searchText", required = false) String param,@RequestParam("pageNumber") int pageNumber, @RequestParam("pageSize") int pageSize) {PagableResponse<RoleVO> response = new PagableResponse<RoleVO>();response.setPageNumber(pageNumber);response.setPageSize(pageSize);PageRequest pageRequest = new PageRequest(pageNumber, pageSize);try {List<RoleVO> data = roleService.findPageableRoles(param, roleId, pageRequest);long count = roleService.count(param, roleId);response.setList(data);response.setCount(count);response.setCode(ReturnCode.SUCCESS);response.setMsg("获取角色信息成功！");} catch(Exception e) {e.printStackTrace();response.setCode(ReturnCode.FAILURE);response.setMsg("获取角色信息失败！"); }return response;}

Service

　　@Overridepublic List<RoleVO> findPageableRoles(String param, String relyCondition, PageRequest pageRequest) {List<RoleVO> list = new ArrayList<RoleVO>();Map<String, Object> map = QueryTool.parseCondition(relyCondition); //添加搜索添加if(StringUtils.isNotBlank(param)){map.put(Operator.LIKE+"_roleName", param);map.put(Operator.LIKE+"_roleCode", relyCondition);}if(StringUtils.isNotBlank(relyCondition)) {map.put(Operator.LIKE+"_id", relyCondition);}map.put(Operator.EQ+"_dr", "0");Specification<RoleEntity> spec = QueryTool.buildSpecification(map, RoleEntity.class);Page<RoleEntity> page = roleDao.findAll(spec, pageRequest);for (RoleEntity entity : page) {RoleVO roleVO = new RoleVO();BeanUtils.copyProperties(entity, roleVO);list.add(roleVO);}return list;}

六、自定义规范

　　实体类

@Entity
@Table(name="sm_role")
public class RoleEntity extends AbsIdEntity implements Serializable{private static final long serialVersionUID = 3717832885014711347L;@Column(name="role_name")private String roleName;@Column(name="role_code")private String roleCode;@Column(name="role_type")private String roleType;@Column(name="isactive")private String isactive;@Column(name="tenant_id")private String tenantId;@Column(name="dtype")private String dtype;@Column(name="remark")private String remark;@Column(name="creator")private String creator;@Column(name="reviser")private String reviser;@Column(name="role_property")private String roleProperty;@Column(name="related_post_id")private String relatedPostId;@Column(name = "instruction")private String instruction;public String getInstruction() {return instruction;}public void setInstruction(String instruction) {this.instruction = instruction;}public String getRoleName() {return roleName;}public void setRoleName(String roleName) {this.roleName = roleName;}public String getRoleCode() {return roleCode;}public void setRoleCode(String roleCode) {this.roleCode = roleCode;}public String getRoleType() {return roleType;}public void setRoleType(String roleType) {this.roleType = roleType;}public String getIsactive() {return isactive;}public void setIsactive(String isactive) {this.isactive = isactive;}public String getTenantId() {return tenantId;}public void setTenantId(String tenantId) {this.tenantId = tenantId;}public String getDtype() {return dtype;}public void setDtype(String dtype) {this.dtype = dtype;}public String getRemark() {return remark;}public void setRemark(String remark) {this.remark = remark;}public String getCreator() {return creator;}public void setCreator(String creator) {this.creator = creator;}public String getReviser() {return reviser;}public void setReviser(String reviser) {this.reviser = reviser;}public String getRoleProperty() {return roleProperty;}public void setRoleProperty(String roleProperty) {this.roleProperty = roleProperty;}public String getRelatedPostId() {return relatedPostId;}public void setRelatedPostId(String relatedPostId) {this.relatedPostId = relatedPostId;}
}

　　自定义Specification

public class RoleSpecification implements Specification<RoleEntity> {private Integer delete = new Integer(0);// 默认查询未删除的数据private String searchParam;private String roleId;public RoleSpecification(String searchParam, String roleId) {super();this.searchParam = searchParam;this.roleId = roleId;}@Overridepublic Predicate toPredicate(Root<RoleEntity> root, CriteriaQuery<?> query, CriteriaBuilder cb) {List<Predicate> list = new ArrayList<Predicate>();list.add(cb.equal(root.get("dr").as(Integer.class), delete));if (StringUtils.isNotBlank(searchParam)) {list.add(cb.or(cb.like(root.get("roleName").as(String.class), cb.literal("%" + searchParam + "%")),cb.like(root.get("roleCode").as(String.class), cb.literal("%" + searchParam + "%")),cb.like(root.get("roleType").as(String.class), cb.literal("%" + searchParam + "%"))));}//角色idif(roleId != null && !("".equals(roleId.trim()))) {list.add(cb.equal(root.get("roleId").as(String.class), roleId));}Predicate[] predicates = new Predicate[list.size()];return cb.and(list.toArray(predicates));}public Integer getDelete() {return delete;}public void setDelete(Integer delete) {this.delete = delete;}public String getSearchParam() {return searchParam;}public void setSearchParam(String searchParam) {this.searchParam = searchParam;}public String getRoleId() {return roleId;}public void setRoleId(String roleId) {this.roleId = roleId;}
}

　　注：规范中操作的 字段名称 都是 实体类的字段名称，不要写成数据库字段名称。

　　自定义规范可以自定义条件查询，比如 or， and等等，使用QueryTool工具建立的规范默认条件都是and，所以很多情况下不能满足我们的需求。总的来说，现在刚刚接触，Spring Data JPA 的 Specification 还要进一步学习。

七、其他通过Specification实现分页查询，请参考

    springmvc+jpa实现分页的两种方式

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