一、前置条件
确定使用的IDE是IntelliJ IDEA；
确保已经创建了一个Spring MVC的web工程；
确保已经配置好了Layui相关的静态资源。
二、添加依赖
添加spring-data-jpa、MySQL JDBC驱动、Spring Web MVC等依赖。



    org.springframework
    spring-webmvc
    ${spring.version}




    org.springframework.data
    spring-data-jpa
    ${spring-data.version}




    mysql
    mysql-connector-java
    ${mysql-connector.version}

三、创建数据表格
使用Layui实现一个数据表格，并添加搜索功能。



四、添加Controller
创建UserController，添加查询用户数据的方法。

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/query")
    @ResponseBody
    public Result query(UserSearchCondition condition) {
        Page page = userService.findByCondition(condition);
        return Result.success(page);
    }
}

// UserSearchCondition.java
@Data
public class UserSearchCondition {

    private Integer page = 1;

    private Integer limit = 10;

    private String key;

    public Pageable getPageable() {
        return PageRequest.of(page - 1, limit);
    }
}

// UserService.java
public interface UserService {

    Page findByCondition(UserSearchCondition condition);
}

// UserServiceImpl.java
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserRepository repository;

    @Override
    public Page findByCondition(UserSearchCondition condition) {
        UserSpecification specification = new UserSpecification(condition);
        return repository.findAll(specification, condition.getPageable());
    }
}

// UserSpecification.java
public class UserSpecification implements Specification {

    private UserSearchCondition condition;

    public UserSpecification(UserSearchCondition condition) {
        this.condition = condition;
    }

    @Override
    public Predicate toPredicate(Root root, CriteriaQuery query, CriteriaBuilder cb) {
        List predicates = new ArrayList<>();
        if (StringUtils.isNotEmpty(condition.getKey())) {
            String pattern = "%" + condition.getKey() + "%";
            Predicate usernameLike = cb.like(root.get("username"), pattern);
            Predicate emailLike = cb.like(root.get("email"), pattern);
            Predicate phoneLike = cb.like(root.get("phone"), pattern);
            predicates.add(cb.or(usernameLike, emailLike, phoneLike));
        }
        return cb.and(predicates.toArray(new Predicate[0]));
    }
}
五、编写SQL脚本
创建user表，并向表中添加一些测试数据。例如：

CREATE TABLE user (
  id int(11) NOT NULL AUTO_INCREMENT,
  username varchar(32) NOT NULL COMMENT '用户名',
  email varchar(64) NOT NULL COMMENT '邮箱',
  phone varchar(16) NOT NULL COMMENT '手机',
  password varchar(64) NOT NULL COMMENT '密码',
  create_time datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  update_time datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
  PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户信息表';

INSERT INTO user (id, username, email, phone, password, create_time, update_time)
VALUES
    (1, 'admin', 'admin@qq.com', '13800138000', '123456', '2021-09-15 16:14:12', '2021-09-15 16:14:12'),
    (2, 'tom', 'tom@qq.com', '13900139000', '123456', '2021-09-15 16:14:36', '2021-09-15 16:14:36'),
    (3, 'jack', 'jack@qq.com', '13600136000', '123456', '2021-09-15 16:14:49', '2021-09-15 16:14:49');