Java基于Springboot实现实体设计和用户登陆和分页显示

2022-07-31,,,,

基于Springboot实现 实体设计+用户登陆+分页显示

实体设计

针对系统功能,我们构建了Type, News, Tags, User, Comment五大实体类

其中

  1. 一种Type包含着多条News
  2. 一条News可以有多个Tag
  3. 一种Tag可能包含多个News
  4. 一个User可以发多个News
  5. 一条News有多个Comment

用户登录

  1. 首先,在pom.xml添加依赖
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>com.atlassian.commonmark</groupId> <artifactId>commonmark</artifactId> <version>0.10.0</version> </dependency> <dependency> <groupId>com.atlassian.commonmark</groupId> <artifactId>commonmark-ext-heading-anchor</artifactId> <version>0.10.0</version> </dependency> <dependency> <groupId>com.atlassian.commonmark</groupId> <artifactId>commonmark-ext-gfm-tables</artifactId> <version>0.10.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> <optional>true</optional> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> <!--<scope>runtime</scope>--> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-validation</artifactId> </dependency> </dependencies> 
  1. 创建文件目录如下

  2. 具体代码实现
    先在po中创建User类

package com.xxxxbt.news.po; import javax.persistence.*; import java.util.ArrayList; import java.util.Date; import java.util.List; @Entity @Table(name = "t_user") public class User { @Id //主键标识 @GeneratedValue(strategy = GenerationType.IDENTITY) //自增 private Long id; private String nickname; private String username; private String password; private String email; private String avatar; private Integer type; @Temporal(TemporalType.TIMESTAMP) //指定时间戳 private Date createTime; @Temporal(TemporalType.TIMESTAMP) //指定时间戳 private Date updateTime; //一对多关系的新闻 @OneToMany(mappedBy = "user") private List<News> newsList = new ArrayList<>(); public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getNickname() { return nickname; } public void setNickname(String nickname) { this.nickname = nickname; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getAvatar() { return avatar; } public void setAvatar(String avatar) { this.avatar = avatar; } public Integer getType() { return type; } public void setType(Integer type) { this.type = type; } public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } public Date getUpdateTime() { return updateTime; } public void setUpdateTime(Date updateTime) { this.updateTime = updateTime; } public List<News> getNewsList() { return newsList; } public void setNewsList(List<News> newsList) { this.newsList = newsList; } @Override public String toString() { return "User{" + "id=" + id + ", nickname='" + nickname + '\'' + ", username='" + username + '\'' + ", password='" + password + '\'' + ", email='" + email + '\'' + ", avatar='" + avatar + '\'' + ", type=" + type + ", createTime=" + createTime + ", updateTime=" + updateTime + ", newsList=" + newsList + '}'; } } 

在dao中创建接口UserRepository, jpa将根据User类型和name属性从数据库中获取指定对象

package com.xxxxbt.news.dao; import com.xxxxbt.news.po.User; import org.springframework.data.jpa.repository.JpaRepository; public interface UserRepository extends JpaRepository<User,Long> { User findByUsernameAndPassword(String username, String password); } 

在service中创建接口UserService

package com.xxxxbt.news.service; import com.xxxxbt.news.po.User; public interface UserService { User checkUsers(String username, String password); } 

在service.impl中实现UserService接口

package com.xxxxbt.news.service.impl; import com.xxxxbt.news.dao.UserRepository; import com.xxxxbt.news.po.User; import com.xxxxbt.news.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class UserServiceImpl implements UserService { @Autowired private UserRepository userRepository; @Override public User checkUsers(String username, String password) { return userRepository.findByUsernameAndPassword(username,password); } } 

最后在web.admin下添加控制器LoginController

package com.xxxxbt.news.web.admin; import com.xxxxbt.news.po.User; import com.xxxxbt.news.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.servlet.mvc.support.RedirectAttributes; import javax.servlet.http.HttpSession; @Controller @RequestMapping("/admin") public class LoginController { @Autowired UserService userService; //跳转到登陆界面 @GetMapping public String loginPage(){ return "admin/login"; } @PostMapping("/login") public String login(@RequestParam String username , @RequestParam String password, HttpSession session, RedirectAttributes attributes) { User user = userService.checkUsers(username, password); if (user != null) { user.setPassword(null); session.setAttribute("user", user); return "admin/index"; } else { attributes.addFlashAttribute("message", "用户名或密码错误"); return "redirect:/admin"; } } @GetMapping("/logout") public String logout(HttpSession session){ session.removeAttribute("user"); return "redirect:/admin"; } } 
  1. 界面展示( 登录前需要在数据库中手动添加用户数据

分页显示

该功能基于Type类实现

  1. 具体代码实现
    先在po中创建Type 类
package com.xxxxbt.news.po; import javax.persistence.*; import javax.validation.constraints.NotBlank; import java.util.ArrayList; import java.util.List; @Entity @Table(name = "t_type") public class Type { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) //自增 private Long id; @NotBlank(message = "分类名称不能为空") private String name; @OneToMany(mappedBy = "type") private List<News> news = new ArrayList<>(); public Type() { } public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public List<News> getNews() { return news; } public void setNews(List<News> news) { this.news = news; } @Override public String toString() { return "Type{" + "id=" + id + ", name='" + name + '\'' + '}'; } } 

在dao中创建接口TypeRepository

package com.xxxxbt.news.dao; import com.xxxxbt.news.po.Type; import org.springframework.data.jpa.repository.JpaRepository; public interface TypeRepository extends JpaRepository<Type,Long> { } 

在service中创建接口TypeService

package com.xxxxbt.news.service; import com.xxxxbt.news.po.Type; import org.springframework.data.domain.Page; import org.springframework.data.domain.Pageable; public interface TypeService { Page<Type> listType(Pageable pageable); } 

在service.impl中实现TypeService 接口

package com.xxxxbt.news.service.impl; import com.xxxxbt.news.dao.TypeRepository; import com.xxxxbt.news.po.Type; import com.xxxxbt.news.service.TypeService; import org.springframework.beans.BeanUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.domain.Page; import org.springframework.data.domain.Pageable; import org.springframework.stereotype.Service; @Service public class TypeServiceImpl implements TypeService { @Autowired private TypeRepository typeRepository; @Override public Page<Type> listType(Pageable pageable) { return typeRepository.findAll(pageable); //findAll方法来自jpa } } 

最后在web.admin下添加控制器TypeController

package com.xxxxbt.news.web.admin; import com.xxxxbt.news.po.Type; import com.xxxxbt.news.service.TypeService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.domain.Pageable; import org.springframework.data.domain.Sort; import org.springframework.data.web.PageableDefault; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.mvc.support.RedirectAttributes; import javax.validation.Valid; @Controller @RequestMapping("/admin") public class TypeController { @Autowired private TypeService typeService; @RequestMapping("/types") public String type(@PageableDefault(size = 3,sort = {"id"},direction = Sort.Direction.DESC) Pageable pageable, Model model){ model.addAttribute("page",typeService.listType(pageable)); return "admin/types"; } } 
  1. 界面展示
    数据展示界面

    url中的page参数将决定当前页的数据

本文地址:https://blog.csdn.net/xxxxxbt/article/details/107650825

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