寫一個Spring Boot的Hello World

儘管這個demo也就hello world水平，但我仍是要記錄一下（總算能動了QAQ），畢竟總是看文章不動手不行啊

上次寫Servlet的CRUD項目仍是2月份，雖然代碼忘的差很少了，但我就記得JDBC寫起來特別累，做爲入門仍是學學Spring吧，然而被Spring的配置勸退了（如今看好像也不是問題，只是沒有那種經驗，碰到就懵逼），如今改用SpringBoot了，而且學習牛客網上的小demo做爲入門參考

從啥都不會到寫個能動的Spring Boot應用須要知道如下概念↓

1.maven構建項目的套路，爲了方便還要會改國內源（而後當你配置好後發現IDEA竟然用自帶的配置）

2.MVC架構，其中controller就是至關於一個服務器的入口

3.註解的用法，初次接觸到高度封裝的代碼我確實頭疼，一個@就完事的非侵入式寫法很難明白它的原理（由於過於隱蔽了）

4.項目常規的通用結構，因爲沒有寫過正經的項目，我也不懂該怎麼分orz（只會DAO），參考一個project能解決這種問題（核心是在於瞭解MVC的細分）

5.懂設計模式，感謝本身幾個月前瞭解了很多設計模式，核心的IOC/AOP不是問題（雖然這裏沒體現）

6.瞭解一下用於注入的XML，前幾天的物聯網（安卓）實驗課上用了XML做爲顯式的注入，瞭解這個過程雖然用不上但會更明白Spring（Boot）的隱式注入是咋回事

7.同理，瞭解AOP的過程就是要嘗試寫一個靜態代理，而後到動態代理

8.不知道是mybatis封裝的太好仍是怎樣，起碼能動的水平只要你會@個CRUD就好

9.關於view的部分，我我的認爲目前會對着改網頁便可

10.項目中剩餘部分暫留

因爲這只是hello world水平的記錄，所以代碼也十分的hello world。。

項目結構以下（test/biz/utils等暫無），具體class/interface以.java區分

|------------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.更新個截圖版

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的配置我沒有查過官方文檔，直接套用別人的，篇幅問題只放出mybatis方便之後抄（刪去）

<?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>圖書列表</title>
</head>
<body>
<div align="center">
    <h3>圖書列表</h3>

<table border="1" cellpadding="10">
    <tr>
        <td>書名</td>
        <td>做者</td>
        <td>價格</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做爲檢查是否正常運行

<!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.數據庫記得寫好表

1.即便是最簡單的項目也有必定的依賴關係，所以從哪裏寫起也是一個問題，我的作法是先寫好controller，畫草稿寫設計一個模塊須要什麼東西，好比一個serive的完成順序model->DAO->service

2.比較晦澀的註解能夠用IDE的源碼查看下載大概看一下

3.一路寫過去大機率完蛋，能夠用簡單的頁面debug一下，或者寫好test

4.本身太菜是個問題

完成這些那就意味着我總算能動個人OJ項目了

指望能儘早肝出來