springboot从入门到精通(二)

时间:2022-12-21 22:45:15

这一节我们一起用springboot开发一个应用程序,应用程序里的核心概念是玩家获取英雄列表上的英雄信息。

1、定义实体模型:

代码如下:

package com.dota.herolist.entity;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Hero {
  private Long id;
  private String name;
  private String type;
  private Integer bloodValue;
  private Integer attack;

  /*AUTO主键由程序控制, 是默认选项 ,不设置就是这个
  -IDENTITY 主键由数据库生成, 采用数据库自增长, Oracle不支持这种方式
  -SEQUENCE 通过数据库的序列产生主键, MYSQL 不支持
  -Table 提供特定的数据库产生主键, 该方式更有利于数据库的移植*/
  @Id
  @GeneratedValue(strategy=GenerationType.AUTO)
  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 String getType() {
    return type;
  }
  public void setType(String type) {
    this.type = type;
  }
  public Integer getBloodValue() {
    return bloodValue;
  }
  public void setBloodValue(Integer bloodValue) {
    this.bloodValue = bloodValue;
  }
  public Integer getAttack() {
    return attack;
  }
  public void setAttack(Integer attack) {
    this.attack = attack;
  }
}

Hero类就是简单的java对象,@Entity注解表示它是一个JPA实体,Id属性为主键,

2、定义持久层,代码如下:

package com.dota.herolist.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

import com.dota.herolist.entity.Hero;

public interface HeroListRepository extends JpaRepository<Hero,Long>{
  List<Hero> findByName(String name);
}

3、创建web界面:

package com.dota.herolist.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.dota.herolist.entity.Hero;
import com.dota.herolist.repository.HeroListRepository;

@Controller
@RequestMapping("/heroList")
public class HeroListController {

  private HeroListRepository heroListRepository;
  @Autowired
  public HeroListController(HeroListRepository heroListRepository){
    this.heroListRepository=heroListRepository;
  }
  @RequestMapping(value="/{name}",method=RequestMethod.GET)
  public String heroList(@PathVariable("name") String name,Model model){
    List<Hero> heroList=heroListRepository.findByName(name);
    if(heroList!=null){
      model.addAttribute("heros",heroList);
    }
    return "heroList";
  }
  @RequestMapping(value="/{name}",method=RequestMethod.POST)
  public String addToHeroList(@PathVariable("name") String name,Hero hero){
    heroListRepository.save(hero);
    return "redirect:/heroList/{name}";
  }

}

写完controller后在src/main/resources/templates里创建一个名为heroList.html的文件:

<html>
<head>
<title>Hero List</title>
<link rel="stylesheet" th:href="@{/style.css}"></link>
</head>
<body>
<h2>Dota Hero List</h2>
<div th:unless="${#lists.isEmpty(heros)}">
<dl th:each="hero : ${heros}">
<dt class="heroHeadLine">
<span th:text="${hero.name}"></span>
<span th:text="${hero.type}"></span>
</dt>
<dd class="heroDescription">
<span th:if="${hero.description}" th:text="${hero.description}">
Description
</span>
<span th:if="${hero.description eq null}">
No description !
</span>
</dd>
</dl>
</div>
<div th:if="${#lists.isEmpty(heros)}">
<p>No Hero!</p>
</div>

<hr/>

<h3>Add a hero</h3>
<form method="POST">
<label for="name">Name:</label>
<input type="text" name="name" size="50"/><br/>
<label for="type">Type:</label>
<input type="text" name="type" size="50"/><br/>
<label for="bloodValue">BloodValue:</label>
<input type="text" name="bloodValue" size="50"/><br/>
<label for="attack">Attack:</label>
<input type="text" name="attack" size="50"/><br/>
<label for="description">Description:</label>
<textarea type="text" name="description" cols="80" rows="5"/></textarea><br/>
<input type="submit"></input>
</form>

</body>
</html>

再在src/main/resources/static下创建一个css文件:

body{background-color:#cccccc;
font-family:arial,helvetica,sans-serif;
}
.heroHeadLine{font-size:12pt;font-weight:bold;
}
.heroDescription{font-size:10pt;}
label{font-weight:bold;}

然后运行程序,启动成功后,访问路径http://localhost:9090/heroList/zhangfei  ,会显示如下界面:

springboot从入门到精通(二)

然后可通过表单添加一些信息,如下图:

springboot从入门到精通(二)

提交表单,然后访问:springboot从入门到精通(二)

很神奇!我们这节就到这里,下节再分析!