Idea新建SpringBoot從零到有【記錄】

時間 2019-11-20

標籤 idea 新建 springboot 到有記錄欄目 Eclipse 简体版

原文原文鏈接

1）準備工具Ideahtml

2）瞭解實現的功能點 1）新建項目 2）部署war 3）訪問jsp 4）針對錯誤頁的顯示 5）配置端口 6）鏈接數據庫 7）CRUD 8)分頁java

2）按步驟完成紅色標記可修改mysql

4）配置pom.xml 也就是同步架包git

<?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.song</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>
	<description>springboot</description>
	<name>demo</name>

	<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>
		</dependency>
		<!-- servlet依賴. -->
		<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>
        <!--熱部署-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<optional>true</optional> <!-- 這個須要爲 true 熱部署纔有效 -->
		</dependency>
		<!-- mysql-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.21</version>
		</dependency>

		<!-- mybatis -->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.1.1</version>
		</dependency>
		<!-- pagehelper 分頁使用 -->
		<dependency>
			<groupId>com.github.pagehelper</groupId>
			<artifactId>pagehelper</artifactId>
			<version>4.1.6</version>
		</dependency>
	</dependencies>
    <!--版本-->
	<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>

5）選擇自動導入時間根據maven的配置下載地址下載github

6）Java下新建操做包及webapp，重構com.song.demo修改成com.song DemoApplication要放在com.song包下，結果結構以下web

7)main下新建webapp ->WEB-INF->jsp 用來存放jsp文件 spring

8）目錄新建完畢。接下來咱們要來講明文件夾的做用sql

config-->配置類分頁使用數據庫

mapper->映射相關的類增刪改查使用apache

pojo->實體類

web->控制器

jsp->存放視圖的地方

9)首先想操做數據庫須要新建數據庫 spring 並新建表 Category

10）必須得有實體類在pojo下新建類 Category 建議與數據庫表名相同

package com.song.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;
    }
      
}

11）綁定映射在mapper下新建映射類

package com.song.mapper;

import java.util.List;

import org.apache.ibatis.annotations.*;

import com.song.pojo.Category;

@Mapper
public interface CategoryMapper {
 
    @Select("select * from category")
    List<Category> findAll();
    @Insert("insert into category ( name ) values (#{name}) ")
    public int save(Category category);

    @Delete(" delete from category where id= #{id} ")
    public void delete(int id);

    @Select("select * from category where id= #{id} ")
    public Category get(int id);

    @Update("update category set name=#{name} where id=#{id} ")
    public int update(Category category);

}

　12)導入分頁的配置在config下錄入類

package com.song.config;

import java.util.Properties;
 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
import com.github.pagehelper.PageHelper;
 
@Configuration
public class PageHelperConfig {
 
    @Bean
    public PageHelper pageHelper() {
        PageHelper pageHelper = new PageHelper();
        Properties p = new Properties();
        p.setProperty("offsetAsPageNum", "true");
        p.setProperty("rowBoundsWithCount", "true");
        p.setProperty("reasonable", "true");
        pageHelper.setProperties(p);
        return pageHelper;
    }
}

　　13）resources下applocation.properties 配置 1）jsp訪問的配置及MYBATIS配置 2）文件上傳的配置

#jsp配置
spring.mvc.view.prefix=/WEB-INF/jsp/
spring.mvc.view.suffix=.jsp
#端口配置及路徑
server.port=8888
server.context-path=/test
#配置切換
#spring.profiles.active=dev
#Mybatis配置
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/spring?characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=123
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.properties.hibernate.hbm2ddl.auto=update
#文件上傳
spring.http.multipart.maxFileSize=100Mb
spring.http.multipart.maxRequestSize=100Mb

　　14)建立控制器，在web下新建以下控制器

1）HelloController 用於測試異常頁的顯示

package com.song.web;
import java.text.DateFormat;
import java.util.Date;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {

    @RequestMapping("/hello")
    public String hello(Model m)  throws Exception{
        m.addAttribute("now", DateFormat.getDateTimeInstance().format(new Date()));
        //註釋此處代碼便可直接進入hello頁
        if(true){
              throw new Exception("some exception");
        }
        return "hello";
    }
}

　　 1.1）GlobalExceptionHandler 異常方法非控制器

package com.song.web;
 
import javax.servlet.http.HttpServletRequest;
 
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;
 
@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(value = Exception.class)
    public ModelAndView defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception {
        ModelAndView mav = new ModelAndView();
        mav.addObject("exception", e);
        mav.addObject("url", req.getRequestURL());
        mav.setViewName("errorPage");
        return mav;
    }
}

　　2）CategoryController 實現分頁及CRUD

package com.song.web;

import java.util.List;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
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.song.mapper.CategoryMapper;
import com.song.pojo.Category;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class CategoryController {
    @Autowired CategoryMapper categoryMapper;
    @RequestMapping("/listCategory")
    public String listCategory(Model m, @RequestParam(value = "start", defaultValue = "0") int start, @RequestParam(value = "size", defaultValue = "5") int size) throws Exception {
        PageHelper.startPage(start,size,"id desc");
        List<Category> cs=categoryMapper.findAll();
        PageInfo<Category> page = new PageInfo<>(cs);
        m.addAttribute("page", page);
        //m.addAttribute("cs", cs);
        return "listCategory";
    }
    @RequestMapping("/addCategory")
    public String listCategory(Category c) throws Exception {
        categoryMapper.save(c);
        return "redirect:listCategory";
    }
    @RequestMapping("/deleteCategory")
    public String deleteCategory(Category c) throws Exception {
        categoryMapper.delete(c.getId());
        return "redirect:listCategory";
    }
    @RequestMapping("/updateCategory")
    public String updateCategory(Category c) throws Exception {
        categoryMapper.update(c);
        return "redirect:listCategory";
    }
    @RequestMapping("/editCategory")
    public String listCategory(int id,Model m) throws Exception {
        Category c= categoryMapper.get(id);
        m.addAttribute("c", c);
        return "editCategory";
    }


      
}

　　3)UploadController 實現文件上傳

package com.song.web;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
 
import javax.servlet.http.HttpServletRequest;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
  
@Controller
public class UploadController {
  
    @RequestMapping("/uploadPage")
    public String uploadPage() {
        return "uploadPage";
    }
    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    public String upload(HttpServletRequest req, @RequestParam("file") MultipartFile file,Model m) {
        try {
            String fileName = System.currentTimeMillis()+file.getOriginalFilename();
            String destFileName=req.getServletContext().getRealPath("")+"uploaded"+File.separator+fileName;

            File destFile = new File(destFileName);
            destFile.getParentFile().mkdirs();
            file.transferTo(destFile);
            m.addAttribute("fileName",fileName);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return "上傳失敗," + e.getMessage();
        } catch (IOException e) {
            e.printStackTrace();
            return "上傳失敗," + e.getMessage();
        }

        return "showImg";
    }
}

　　15）完成目錄以下

16)修改 DemoApplication 由於使用war部署方式，因此之前jar的不使用

package com.song;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
@ServletComponentScan
public class DemoApplicationTests extends SpringBootServletInitializer  {

	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
		return application.sources(DemoApplicationTests.class);
	}

	public static void main(String[] args) {
		SpringApplication.run(DemoApplicationTests.class, args);
	}
}

　　17）增長視圖在 jsp文件夾下

1)hello.jsp 在hello控制器下注釋相應代碼if(true)部分，進入的頁面

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
Hi JSP. 如今時間是  ${now}

2)errorPage.jsp 錯誤提示頁

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>

<div style="width:500px;border:1px solid lightgray;margin:200px auto;padding:80px">

    系統 出現了異常，異常緣由是：
    ${exception}
    <br><br>
    出現異常的地址是：
    ${url}
</div>

3)listCategory.jsp 列表頁

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<div align="center">

</div>

<div style="width:500px;margin:20px auto;text-align: center">
    <table align='center' border='1' cellspacing='0'>
        <tr>
            <td>id</td>
            <td>name</td>
            <td>編輯</td>
            <td>刪除</td>
        </tr>
        <c:forEach items="${page.list}" var="c" varStatus="st">
            <tr>
                <td>${c.id}</td>
                <td>${c.name}</td>
                <td><a href="editCategory?id=${c.id}">編輯</a></td>
                <td><a href="deleteCategory?id=${c.id}">刪除</a></td>
            </tr>
        </c:forEach>

    </table>
    <br>
    <div>
        <a href="?start=1">[首  頁]</a>
        <a href="?start=${page.pageNum-1}">[上一頁]</a>
        <a href="?start=${page.pageNum+1}">[下一頁]</a>
        <a href="?start=${page.pages}">[末  頁]</a>
    </div>
    <br>
    <form action="addCategory" method="post">

        name: <input name="name"> <br>
        <button type="submit">提交</button>

    </form>
</div>

4)editCategory.jsp 編輯頁

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8" isELIgnored="false"%>

<div style="margin:0px auto; width:500px">

    <form action="updateCategory" method="post">

        name: <input name="name" value="${c.name}"> <br>

        <input name="id" type="hidden" value="${c.id}">
        <button type="submit">提交</button>

    </form>
</div>

5)showImg.jsp 圖片展現頁

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
 圖片 ${fileName} <img src="uploaded/${fileName}">

6)uploadPage.jsp 文件上傳頁

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>

<form action="upload" method="post" enctype="multipart/form-data">
    選擇圖片:<input type="file" name="file" accept="image/*" /> <br>
    <input type="submit" value="上傳">
</form>

　　18）完成目錄以下

19）運行測試

http://127.0.0.1:8888/test/listCategory    //列表頁

http://127.0.0.1:8888/test/hello           //異常頁

http://127.0.0.1:8888/test/uploadPage      //上傳文件頁

　　20）重點記憶

1）idea下pom.xml下不該有<scope></scope>

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