10.MYBATIS注解方式

application.properties

新增数据库链接必须的参数
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spring.mvc.view.prefix=/WEB-INF/jsp/
spring.mvc.view.suffix=.jsp
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/how2java?characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=admin
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
 步骤 9 : 

pom.xml

增加对mysql和mybatis的支持
 
<!-- mybatis -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.21</version>
</dependency>
 
 
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
 
  <groupId>com.how2java</groupId>
  <artifactId>springboot</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>springboot</name>
  <description>springboot</description>
  <packaging>war</packaging>
   
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
             
        </dependency>
        <dependency>
              <groupId>junit</groupId>
              <artifactId>junit</artifactId>
              <version>3.8.1</version>
              <scope>test</scope>
        </dependency>
        <!-- servlet依赖. -->
        <dependency>
              <groupId>javax.servlet</groupId>
              <artifactId>javax.servlet-api</artifactId>
               
        </dependency>
              <dependency>
                     <groupId>javax.servlet</groupId>
                     <artifactId>jstl</artifactId>
              </dependency>
        <!-- tomcat的支持.-->
        <dependency>
               <groupId>org.apache.tomcat.embed</groupId>
               <artifactId>tomcat-embed-jasper</artifactId>
                
        </dependency>    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional> <!-- 这个需要为 true 热部署才有效 -->
        </dependency>
         
        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
 
        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.21</version>
        </dependency>
    </dependencies>
 
    <properties>
        <java.version>1.8</java.version>
    </properties>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>
 步骤 10 : 

Category

增加一个包：com.how2java.springboot.pojo，然后创建实体类Category。
 
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package com.how2java.springboot.pojo;
 
public class Category {
  
    private int id;
      
    private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
      
}
 步骤 11 : 

CategoryMapper

增加一个包：com.how2java.springboot.mapper，然后创建接口CategoryMapper。
使用注解@Mapper 表示这是一个Mybatis Mapper接口。
使用@Select注解表示调用findAll方法会去执行对应的sql语句。
 
@Select("select * from category_ ")
List<Category> findAll();
 

关于Mybatis的注解方式有相关的系列教材： Mybatis 注解教程
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package com.how2java.springboot.mapper;
 
import java.util.List;
 
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
 
import com.how2java.springboot.pojo.Category;
 
@Mapper
public interface CategoryMapper {
 
    @Select("select * from category_ ")
    List<Category> findAll();
 
}
 步骤 12 : 

CategoryController

增加一个包：com.how2java.springboot.web，然后创建CategoryController 类。
1. 接受listCategory映射
2. 然后获取所有的分类数据
3. 接着放入Model中
4. 跳转到listCategory.jsp
 
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package com.how2java.springboot.web;
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.RequestMapping;
 
import com.how2java.springboot.mapper.CategoryMapper;
import com.how2java.springboot.pojo.Category;
   
@Controller
public class CategoryController {
    @Autowired CategoryMapper categoryMapper;
      
    @RequestMapping("/listCategory")
    public String listCategory(Model m) throws Exception {
        List<Category> cs=categoryMapper.findAll();
          
        m.addAttribute("cs", cs);
          
        return "listCategory";
    }
      
}
 步骤 13 : 

listCategory.jsp

用jstl遍历从CategoryController 传递过来的集合：cs.
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<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
 
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
   
<table align='center' border='1' cellspacing='0'>
    <tr>
        <td>id</td>
        <td>name</td>
    </tr>
    <c:forEach items="${cs}" var="c" varStatus="st">
        <tr>
            <td>${c.id}</td>
            <td>${c.name}</td>
                
        </tr>
    </c:forEach>
</table>
 步骤 14 : 

重启测试

因为在pom.xml中增加了jar包的依赖，所以仅仅通过Springboot本身的热部署是无法起作用的，得手动重启一下。
然后访问测试地址：
 
http://127.0.0.1:8080/listCategory
 

观察到如图所示的效果
重启测试

posted on 2019-01-04 16:04  我是司  阅读(240)  评论(0)    收藏  举报

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