Spring Boot入门程序（2)

第一步：导入maven依赖

<?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.itpengwei.idea</groupId>
    <artifactId>spring-boothello</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <!-- 有了父包，在dependencies 配置其他包版本都省了 -->
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.1.37</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

第二步:创建一个应用入口类

package com.itpengwei;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

/**
 * 应用入口类
 * 因为入门程序所以使用注解和java配置
 */
@SpringBootApplication
@ComponentScan(basePackages = {"com.itpengwei.config","com.itpengwei.controller"})//配置扫描包
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);

    }


}

同时附上我的包结构

第三步:编写配置文件(application.properties)

第四步:创建一个dao(我这用的是一段静态的json数据，实际开发中换成查数据库就行)

package com.itpengwei.dao;

import com.itpengwei.pojo.Function;
import com.itpengwei.utils.JSonUtils;

public class FunctionMapper {
    public Function getFunction() {
        Function function = JSonUtils.getPojo();
        return function;
    }
}

第五步:创建service

package com.itpengwei.service.impl;

import com.itpengwei.dao.FunctionMapper;
import com.itpengwei.pojo.Function;
import com.itpengwei.service.IFunctionService;
import org.springframework.beans.factory.annotation.Autowired;

public class FunctionServiceImpl implements IFunctionService {
    @Autowired
    private FunctionMapper mapper;
    @Override
    public Function getFunctionById() {
        return mapper.getFunction();
    }
}

第六步:创建controller

package com.itpengwei.controller;

import com.itpengwei.pojo.Function;
import com.itpengwei.service.IFunctionService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @Autowired
    private IFunctionService functionService;
    @RequestMapping(value = "/hello.html",produces ="application/json;charset=utf-8")
    public Function hello() {
        Function functionById = functionService.getFunctionById();
        return functionById;
    }

}

第七步:创建一个配置类

package com.itpengwei.config;

import com.itpengwei.dao.FunctionMapper;
import com.itpengwei.service.IFunctionService;
import com.itpengwei.service.impl.FunctionServiceImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * spring4.x后提倡使用java配置
 */
@Configuration//加上这个注解表示这是一个配置类，就像以前的xml
public class SpringConfig {
    /**
     * 这是在spring容器中创建一个bean
     * 方法名字建议使用类名---首字母小写
     */
    @Bean
    public FunctionMapper functionMapper() {
        return new FunctionMapper();
    }

    @Bean
    public IFunctionService iFunctionService() {
        FunctionServiceImpl functionService = new FunctionServiceImpl();
        return functionService;
    }
}

第八步:去App类里面运行mian方法就行了

成功截图: