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Spring 学习笔记

• Spring 学习笔记《依赖注入》—— 注解

在 的基础上进行。（其源码文件包含了本篇的内容）

注解介绍

Spring

创建 bean

这三个功能相同，名字是为了便于区分所属。默认类名首字小写为 bean 的 id

• @Component 用于 POJO
• @Service 用于服务层
• @Controller 用于控制层

依赖注入

• @AutoWire 要需要依赖注入的属性上声明。默认按 byType 注入
• @Resource 要需要依赖注入的属性上声明。默认注入 byName 失败再 byType
• @Value 从配置文件读取的数据，进行注入 （所以它需要扫描配置文件）
  用法一 带配置文件（就是扫描配置文件的那个bean的id ： configProperties）
  编不下去了，这个我还没用过。。。。

Spring Boot

• @EnableAutoConfiguration 启用Spring引导的自动配置机制（按默认配置给你配）
• @ComponentScan 默认扫描启用类所在包及其所有子包，也可以给参数指定 @ComponentScan(basePackages = {“com.jerry”}) // spring 扫描包
• @Configuration 把当前作为配置类，有配置往这来
• @SpringBootApplication 集齐以上三个注解可以合成 @SpringBootApplication

mybatis

• @MapperScan("com.jerry.springbootdemo.mapper") // mybatis mapper 包类路径

干活

添加别名扫描的包（POJO包）

/springbootdemo/src/main/resources/application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.url=jdbc:mysql://localhost:3306/jerry?serverTimezone=GMT%2B8spring.datasource.username=rootspring.datasource.password=rootspring.mvc.view.prefix: /WEB-INF/jsp/spring.mvc.view.suffix: .jspmybatis.typeAliasesPackage=com.jerry.springbootdemo.entity

以前配置 applicationContext.xml 时是这样的：(举例说明，非完整配置)

启动类添加注解

/springbootdemo/src/main/java/com/jerry/springbootdemo/SpringbootdemoApplication.java

package com.jerry.springbootdemo;import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.annotation.ComponentScan;@SpringBootApplication@MapperScan("com.jerry.springbootdemo.mapper")// mybatis mapper 包类路径public class SpringbootdemoApplication {
   	public static void main(String[] args) {
   		SpringApplication.run(SpringbootdemoApplication.class, args);	}}

添加测试数据

SET FOREIGN_KEY_CHECKS=0;-- ------------------------------ Table structure for poem-- ----------------------------DROP TABLE IF EXISTS `poem`;CREATE TABLE `poem` (  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',  `title` varchar(16) NOT NULL COMMENT '诗词标题',  `content` varchar(255) NOT NULL COMMENT '诗词内容',  `author` varchar(16) NOT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;-- ------------------------------ Records of poem-- ----------------------------INSERT INTO `poem` VALUES ('1', '痴情癫', '
多情黯叹痴情癫，痴情苦笑多情难。
相思自古无良药，从来独步赴黄泉。一壶泪，暗淡醇香味。
化作万樽与谁对？
忧举杯，乐举杯，地老天荒只一醉。
欲哭时，男儿无泪。
千般相思苦。
杯中汇...
', '笑虾');

实体类

/springbootdemo/src/main/java/com/jerry/springbootdemo/entity/Poem.java

package com.jerry.springbootdemo.entity;import org.springframework.stereotype.Component;/** * poem 表实体类  * @author jerryjin 2019-01-24 */public class Poem {
       /** 主键 */    private Long id;    /** 诗词标题 */    private String title;    /** 诗词内容 */    private String content;    private String author;    /**     * 获取：主键     * @return id 主键     */    public Long getId() {
           return id;    }    /**     * 设置：主键     * @param id 主键     */    public void setId(Long id) {
           this.id = id;    }    /**     * 获取：诗词标题     * @return title 诗词标题     */    public String getTitle() {
           return title;    }    /**     * 设置：诗词标题     * @param title 诗词标题     */    public void setTitle(String title) {
           this.title = title == null ? null : title.trim();    }    /**     * 获取：诗词内容     * @return content 诗词内容     */    public String getContent() {
           return content;    }    /**     * 设置：诗词内容     * @param content 诗词内容     */    public void setContent(String content) {
           this.content = content == null ? null : content.trim();    }    /**     * 获取：     * @return author      */    public String getAuthor() {
           return author;    }    /**     * 设置：     * @param author      */    public void setAuthor(String author) {
           this.author = author == null ? null : author.trim();    }}

mapper

/springbootdemo/src/main/java/com/jerry/springbootdemo/mapper/PoemMapper.java

package com.jerry.springbootdemo.mapper;import com.jerry.springbootdemo.entity.Poem;public interface PoemMapper {
       int deleteByPrimaryKey(Long id);    int insert(Poem record);    int insertSelective(Poem record);    Poem selectByPrimaryKey(Long id);    int updateByPrimaryKeySelective(Poem record);    int updateByPrimaryKey(Poem record);}

/springbootdemo/src/main/java/com/jerry/springbootdemo/mapper/PoemMapper.xml

   
     
        
         
         
         
       
      
    
         id, title, content, author  
      
        select         from poem    where id = #{id,jdbcType=BIGINT}    
    
         delete from poem    where id = #{id,jdbcType=BIGINT}  
      
    
         insert into poem (id, title, content,       author)    values (#{id,jdbcType=BIGINT}, #{title,jdbcType=VARCHAR}, #{content,jdbcType=VARCHAR},       #{author,jdbcType=VARCHAR})  
      
    
         insert into poem    
           
      
               id,      
            
      
               title,      
            
      
               content,      
            
      
               author,      
          
         
           
      
               #{id,jdbcType=BIGINT},      
            
      
               #{title,jdbcType=VARCHAR},      
            
      
               #{content,jdbcType=VARCHAR},      
            
      
               #{author,jdbcType=VARCHAR},      
          
       
      
    
         update poem    
           
      
               title = #{title,jdbcType=VARCHAR},      
            
      
               content = #{content,jdbcType=VARCHAR},      
            
      
               author = #{author,jdbcType=VARCHAR},      
          
         where id = #{id,jdbcType=BIGINT}  
      
    
         update poem    set title = #{title,jdbcType=VARCHAR},      content = #{content,jdbcType=VARCHAR},      author = #{author,jdbcType=VARCHAR}    where id = #{id,jdbcType=BIGINT}  
    
   

服务层

/springbootdemo/src/main/java/com/jerry/springbootdemo/service/IPoemService.java

package com.jerry.springbootdemo.service;import com.jerry.springbootdemo.entity.Poem;public interface IPoemService {
   	Poem getById(Long id);	Long save(Poem record);	Long saveAll(Poem record);    int delById(Long id);}

/springbootdemo/src/main/java/com/jerry/springbootdemo/service/impl/PoemService.java

package com.jerry.springbootdemo.service.impl;import javax.annotation.Resource;import org.springframework.stereotype.Service;import com.jerry.springbootdemo.entity.Poem;import com.jerry.springbootdemo.mapper.PoemMapper;import com.jerry.springbootdemo.service.IPoemService;@Servicepublic class PoemService implements IPoemService {
   	//-------------------------------------------------------	@Resource	private PoemMapper poemMapper;		//-------------------------------------------------------	@Override	public Poem getById(Long id) {
   		return poemMapper.selectByPrimaryKey(id);	}		@Override	public Long saveAll(Poem record) {
   		if(record.getId() == null){
   			poemMapper.insert(record);		}else{
   			poemMapper.updateByPrimaryKey(record);		}		return record.getId();	}	@Override	public Long save(Poem record) {
   		if(record.getId() == null){
   			poemMapper.insertSelective(record);		}else{
   			poemMapper.updateByPrimaryKeySelective(record);		}		return record.getId();	}	@Override	public int delById(Long id) {
   		return poemMapper.deleteByPrimaryKey(id);	}		//-----------------------------------------------------------------	}

控制层

/springbootdemo/src/main/java/com/jerry/springbootdemo/controller/WelcomeController.java

package com.jerry.springbootdemo.controller;import java.util.Map;import javax.annotation.Resource;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import com.jerry.springbootdemo.service.IPoemService;@Controllerpublic class WelcomeController {
   	@Resource	private IPoemService poemService;		@RequestMapping("/")	public String welcome(Map
   
     model) {
   		model.put("name", "笨笨");		model.put("poem", poemService.getById(1L));		return "welcome";	}}
   

样式表

/springbootdemo/src/main/resources/static/css/main.css

h1 {
   	color: #03a9f4;}.poem {
       color: #607D8B;}.poem .title {
       font-size: 2.5em;}.poem .author {
       font-size: 1.0em;}.poem .content p {
       font-size: 1.5em;}

JSP

/springbootdemo/src/main/webapp/WEB-INF/jsp/welcome.jsp

<%@ page language="java" pageEncoding="UTF-8"%>			
   				
   
			
    
				
     
大家好，我是${name}，${name}的笨，${name}的笨，谢谢！
				
     
					
      
${poem.title} —— ${poem.author}
					
      
       ${poem.content} 
      
				
     
			
    
		
   
	

看看效果

源码下载

https://download.csdn.net/download/jx520/10935659

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