写一个Spring Boot的Hello World

尽管这个demo也就hello world水平，但我仍是要记录一下（总算能动了QAQ），毕竟总是看文章不动手不行啊

上次写Servlet的CRUD项目仍是2月份，虽然代码忘的差很少了，但我就记得JDBC写起来特别累，做为入门仍是学学Spring吧，然而被Spring的配置劝退了（如今看好像也不是问题，只是没有那种经验，碰到就懵逼），如今改用SpringBoot了，而且学习牛客网上的小demo做为入门参考

从啥都不会到写个能动的Spring Boot应用须要知道如下概念↓

1.maven构建项目的套路，为了方便还要会改国内源（而后当你配置好后发现IDEA竟然用自带的配置）

2.MVC架构，其中controller就是至关于一个服务器的入口

3.注解的用法，初次接触到高度封装的代码我确实头疼，一个@就完事的非侵入式写法很难明白它的原理（由于过于隐蔽了）

4.项目常规的通用结构，因为没有写过正经的项目，我也不懂该怎么分orz（只会DAO），参考一个project能解决这种问题（核心是在于了解MVC的细分）

5.懂设计模式，感谢本身几个月前了解了很多设计模式，核心的IOC/AOP不是问题（虽然这里没体现）

6.了解一下用于注入的XML，前几天的物联网（安卓）实验课上用了XML做为显式的注入，了解这个过程虽然用不上但会更明白Spring（Boot）的隐式注入是咋回事

7.同理，了解AOP的过程就是要尝试写一个静态代理，而后到动态代理

8.不知道是mybatis封装的太好仍是怎样，起码能动的水平只要你会@个CRUD就好

9.关于view的部分，我我的认为目前会对着改网页便可

10.项目中剩余部分暂留

因为这只是hello world水平的记录，所以代码也十分的hello world。。

项目结构以下（test/biz/utils等暂无），具体class/interface以.java区分

|------------com.caturra.training
    |
    |--------BookLibraryApplication.java
    |
    |-------controller
        |
        |----BookController.java
    |--------model
        |----Book
    |--------dao
        |----BookDAO.java
    |--------service
        |----BookService.java
|------------resources
    |--------templates
        |----book
            |----books.html
        |----hello.html
    |-------application.properties
    |-------log4j.properties
    |-------mybatis-config.xml

UPDATE.更新个截图版

如下忽略全限定名

BookLibraryApplication

package com.caturra.training;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class BookLibraryApplication {

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

BookController

package com.caturra.training.controller;

import com.caturra.training.service.BookService;
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 org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class BookController {

    @Autowired
    private BookService bookService;

    @RequestMapping(path = {"/index"},method = {RequestMethod.GET})
    public String getAllBooks(Model model) {
        model.addAttribute("books",bookService.getAll());
        return "book/books";
    }
    @RequestMapping(path = {"/"},method = {RequestMethod.GET})
    public String tempTest() {
        return "hello";
    }
}

Book

package com.caturra.training.model;

public class Book {

    private int id;
    private String title;
    private String author;
    private int    price;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }
}

BookDAO

package com.caturra.training.dao;

import com.caturra.training.model.Book;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface BookDAO {

    String tableName = " book ";
    String insertField = " title, author, price ";
    String selectField = insertField;

    @Select({"SELECT",selectField,"FROM",tableName})
    List<Book> getAll();

    @Insert({"INSERT INTO",tableName,"(",insertField,") VALUES (#{title},#{author},#{price})"})
    int add(Book book);
}

BookService

package com.caturra.training.service;

import com.caturra.training.dao.BookDAO;
import com.caturra.training.model.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class BookService {

    @Autowired
    private BookDAO bookDAO;

    public void add(Book book) {
        bookDAO.add(book);
    }

    public List<Book> getAll() {
        return bookDAO.getAll();
    }
}

application.properties配置

spring.freemarker.suffix=.html

spring.datasource.url=jdbc:mysql://localhost:3306/mybooklib?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
mybatis.config-location=classpath:mybatis-config.xml

mybatis和log4j的配置我没有查过官方文档，直接套用别人的，篇幅问题只放出mybatis方便之后抄（删去）

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

  <settings>
    <!-- Globally enables or disables any caches configured in any mapper under this configuration -->
    <setting name="cacheEnabled" value="true"/>
    <!-- Sets the number of seconds the driver will wait for a response from the database -->
    <setting name="defaultStatementTimeout" value="3000"/>
    <!-- Enables automatic mapping from classic database column names A_COLUMN to camel case classic Java property names aColumn -->
    <setting name="mapUnderscoreToCamelCase" value="true"/>
    <!-- Allows JDBC support for generated keys. A compatible driver is required.
    This setting forces generated keys to be used if set to true,
     as some drivers deny compatibility but still work -->
    <setting name="useGeneratedKeys" value="true"/>
  </settings>

  <!-- Continue going here -->

</configuration>

books.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>图书列表</title>
</head>
<body>
<div align="center">
    <h3>图书列表</h3>

<table border="1" cellpadding="10">
    <tr>
        <td>书名</td>
        <td>做者</td>
        <td>价格</td>
    </tr>
    <#list books as book>
    <tr>
        <td>《${book.title}》</td>
        <td>${book.author}</td>
        <td>${book.price}</td>
    </tr>
</#list>
</table>
</div>
</body>
</html>

hello.html做为检查是否正常运行

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Hello</title>
</head>
<body>
    <p>hello the no offer world!</p>
</body>
</html>

遇到的坑：

0.数据库记得写好表

1.即便是最简单的项目也有必定的依赖关系，所以从哪里写起也是一个问题，我的作法是先写好controller，画草稿写设计一个模块须要什么东西，好比一个serive的完成顺序model->DAO->service

2.比较晦涩的注解能够用IDE的源码查看下载大概看一下

3.一路写过去大几率完蛋，能够用简单的页面debug一下，或者写好test

4.本身太菜是个问题

完成这些那就意味着我总算能动个人OJ项目了

指望能尽早肝出来