Spring Boot入门

　　最近在公司太清闲了，为了打发我过剩的精力，我逛起了微信上关注的几个关于java技术的公众号，有一篇文章上《Java工程师技能表》，上边的技能排名挺有意思的：

其他技能即使在公司项目中没用过，但是咱最少自学过，有点了解。但是Spring Boot竟然排名这么高，那我今天就来入入门。

什么是Spring Boot？特点是什么？

　　Spring Boot是由Pivotal团队提供的全新框架，其设计目的是用来简化新Spring应用的初始搭建以及开发过程。该框架使用了特定的方式来进行配置，从而使开发人员不再需要定义样板化的配置。通过这种方式，Spring Boot致力于在蓬勃发展的快速应用开发领域（rapid application development）成为领导者。

　　特点：

　　　　1. 创建独立的Spring应用程序

　　　　2. 嵌入的Tomcat，无需部署WAR文件

　　　　3. 简化Maven配置

　　　　4. 自动配置Spring

　　　　5. 提供生产就绪型功能，如指标，健康检查和外部配置

　　　　6. 绝对没有代码生成和对XML没有要求配置

-------------------------------------

　　Spring Boot配置简单、功能齐全，如果我们只需要开发一个功能简单的程序，就可以使用Spring Boot，省去繁琐的框架整合时间。

下面就开始进行一个Spring Boot demo的创建吧！

第一步：下载压缩包，导入项目。

　　下载地址： http://start.spring.io/

　　下载获得： demo.zip 解压缩并导入到项目中。

第二步：编写相关代码。

1.pom.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 3     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 4     <modelVersion>4.0.0</modelVersion>
 5 
 6     <groupId>com.example</groupId>
 7     <artifactId>demo</artifactId>
 8     <version>0.0.1-SNAPSHOT</version>
 9     <packaging>jar</packaging>
10 
11     <name>demo</name>
12     <description>Demo project for Spring Boot</description>
13 
14     <parent>
15         <groupId>org.springframework.boot</groupId>
16         <artifactId>spring-boot-starter-parent</artifactId>
17         <version>1.5.2.RELEASE</version>
18         <relativePath /> <!-- lookup parent from repository -->
19     </parent>
20 
21     <properties>
22         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24         <java.version>1.8</java.version>
25     </properties>
26 
27     <dependencies>
28         <dependency>
29             <groupId>org.springframework.boot</groupId>
30             <artifactId>spring-boot-starter</artifactId>
31         </dependency>
32 
33         <dependency>
34             <groupId>org.springframework.boot</groupId>
35             <artifactId>spring-boot-starter-test</artifactId>
36             <scope>test</scope>
37         </dependency>
38 
39 
40         <dependency>
41             <groupId>org.springframework.boot</groupId>
42             <artifactId>spring-boot-starter-web</artifactId>
43         </dependency>
44 
45         <!-- mybatis -->
46         <dependency>
47             <groupId>org.mybatis.spring.boot</groupId>
48             <artifactId>mybatis-spring-boot-starter</artifactId>
49             <version>1.1.1</version>
50         </dependency>
51         <dependency>
52             <groupId>mysql</groupId>
53             <artifactId>mysql-connector-java</artifactId>
54         </dependency>
55         <dependency>
56             <groupId>org.springframework.boot</groupId>
57             <artifactId>spring-boot-devtools</artifactId>
58             <optional>true</optional>
59         </dependency>
60     </dependencies>
61 
62     <build>
63         <plugins>
64             <plugin>
65                 <groupId>org.springframework.boot</groupId>
66                 <artifactId>spring-boot-maven-plugin</artifactId>
67             </plugin>
68         </plugins>
69     </build>
70 
71 
72 </project>

2.application.properties

1 mybatis.type-aliases-package=com.example.myproject.entity
2 
3 spring.datasource.driverClassName = com.mysql.jdbc.Driver
4 spring.datasource.url = jdbc:mysql://localhost:3306/tao?useUnicode=true&characterEncoding=utf-8
5 spring.datasource.username = root
6 spring.datasource.password = 123

3.实体类

 1 package com.example.myproject.entity;
 2 
 3 import java.io.Serializable;
 4 
 5 public class User implements Serializable {
 6     private String username;
 7     private String password;
 8     private String name;
 9     private String email;
10     public String getUsername() {
11         return username;
12     }
13     public void setUsername(String username) {
14         this.username = username;
15     }
16     public String getPassword() {
17         return password;
18     }
19     public void setPassword(String password) {
20         this.password = password;
21     }
22     public String getName() {
23         return name;
24     }
25     public void setName(String name) {
26         this.name = name;
27     }
28     public String getEmail() {
29         return email;
30     }
31     public void setEmail(String email) {
32         this.email = email;
33     }
34     
35 }

4.DAO层代码

 1 package com.example.myproject.dao;
 2 
 3 import java.util.List;
 4 
 5 import org.apache.ibatis.annotations.Delete;
 6 import org.apache.ibatis.annotations.Insert;
 7 import org.apache.ibatis.annotations.Select;
 8 import org.apache.ibatis.annotations.Update;
 9 
10 import com.example.myproject.entity.User;
11 
12 public interface UserDao {
13     @Select("SELECT * FROM user")
14     List<User> getAll();
15 
16     @Select("SELECT * FROM user WHERE username = #{username}")
17     User getOne(String username);
18 
19     @Insert("INSERT INTO user(username,password,name,email) VALUES(#{username}, #{password}, #{name}, #{email})")
20     void insert(User user);
21 
22     @Update("UPDATE user SET name=#{name} WHERE username =#{username}")
23     void updateNameByUsername(User user);
24 
25     @Delete("DELETE FROM user WHERE username =#{username}")
26     void delete(String username);
27 }

5.service层代码

 1 package com.example.myproject.service;
 2 
 3 import java.util.List;
 4 
 5 import com.example.myproject.entity.User;
 6 
 7 public interface UserService {
 8     /**
 9      * 查询全部user
10      * @return
11      */
12     List<User> getAll();
13     /**
14      * 根据username查询一条user
15      * @param username
16      * @return
17      */
18     User getOne(String username);
19     /**
20      * 插入一条user
21      * @param user
22      */
23     void insert(User user);
24     /**
25      * 根据username查到user，修改name
26      * @param user
27      */
28     void updateNameByUsername(User user);
29     /**
30      * 删除user
31      * @param username
32      */
33     void delete(String username);
34 }

 1 package com.example.myproject.service.impl;
 2 
 3 import java.util.List;
 4 
 5 import org.springframework.beans.factory.annotation.Autowired;
 6 import org.springframework.stereotype.Service;
 7 
 8 import com.example.myproject.dao.UserDao;
 9 import com.example.myproject.entity.User;
10 import com.example.myproject.service.UserService;
11 
12 @Service("userService")
13 public class UserServiceImpl implements UserService {
14     
15     
16     @Autowired
17     private UserDao userDao;
18 
19     @Override
20     public List<User> getAll() {
21         return userDao.getAll();
22     }
23 
24     @Override
25     public User getOne(String username) {
26         return userDao.getOne(username);
27     }
28 
29     @Override
30     public void insert(User user) {
31         userDao.insert(user);
32     }
33 
34     @Override
35     public void updateNameByUsername(User user) {
36         userDao.updateNameByUsername(user);
37     }
38 
39     @Override
40     public void delete(String username) {
41         userDao.delete(username);
42     }
43 
44 }

6.controller代码：

 1 package com.example.myproject.action;
 2 
 3 import java.util.List;
 4 
 5 import org.springframework.beans.factory.annotation.Autowired;
 6 import org.springframework.stereotype.Controller;
 7 import org.springframework.web.bind.annotation.RequestMapping;
 8 import org.springframework.web.bind.annotation.ResponseBody;
 9 import org.springframework.web.bind.annotation.RestController;
10 
11 import com.example.myproject.entity.User;
12 import com.example.myproject.service.UserService;
13 
14 @Controller
15 public class HelloWorldController {
16     
17     
18     @Autowired(required = false)
19     private UserService userService;
20     
21     
22     @RequestMapping("/getAll")
23     public @ResponseBody List<User> getAll() {
24         return userService.getAll();
25     }
26     
27     @RequestMapping("/getOne")
28     public @ResponseBody User getOne(String username) {
29         return userService.getOne(username);
30     }
31     
32     @RequestMapping("/insert")
33     public @ResponseBody User insert() {
34         User user = new User();
35         user.setUsername("zs");
36         user.setPassword("123456");
37         user.setName("zhangsan");
38         user.setEmail("123@qq.com");
39         userService.insert(user);
40         return userService.getOne("zs");
41     }
42     
43     @RequestMapping("/updateNameByUsername")
44     public @ResponseBody User updateNameByUsername() {
45         User user = new User();
46         user.setUsername("zs");
47         user.setName("zs1111");
48         userService.updateNameByUsername(user);
49         return userService.getOne("zs");
50     }
51     
52     @RequestMapping("/delete")
53     public @ResponseBody List<User> delete() {
54         userService.delete("zs");
55         return userService.getAll();
56     }
57 }

7.运行代码修改：

 1 package com.example;
 2 
 3 import org.mybatis.spring.annotation.MapperScan;
 4 import org.springframework.boot.SpringApplication;
 5 import org.springframework.boot.autoconfigure.SpringBootApplication;
 6 
 7 @SpringBootApplication
 8 //地址到dao层接口处，否则报错
 9 @MapperScan("com.example.myproject.dao")
10 public class DemoApplication {
11 
12     public static void main(String[] args) {
13         SpringApplication.run(DemoApplication.class, args);
14     }
15 }

　　至此，只要运行这个main方法，访问 localhost:8080/getAll 就可以运行了。

　　简单的试用了一下Spring Boot，确实被它简单的配置给惊到了，看来以后自己学点学习的demo时，就用它吧！哈哈。。。

感谢以下博文：

　　http://www.cnblogs.com/ityouknow/p/6037431.html

　　http://www.cnblogs.com/ityouknow/p/5662753.html