Spring-Boot入门

之前项目中有个服务需要独立出来，同事用springboot改成了微服务，这两天没啥忙的就给拿出瞅瞅学习一下~

Demo只是对这个例子重新写了一遍加了一些注释和自己的东西 = =

新建一个maven项目

我用的是IDEA，新建maven项目时，记得添加一个属性 archetypeCatalog=internal

archetypeCatalog表示插件使用的archetype元数据，不加这个参数时默认为remote，local，即中央仓库archetype元数据，由于中央仓库的archetype太多了，所以导致很慢，指定internal来表示仅使用内部元数据

添加配置

在pom.xml文件添加响应的配置



    4.0.0
    
        org.springframework.boot
        spring-boot-tools
        1.5.1.RELEASE
    
    spring-boot-configuration-processor
    Spring Boot Configuration Processor
    Spring Boot Configuration Processor
    http://projects.spring.io/spring-boot/
    
        Pivotal Software, Inc.
        http://www.spring.io
    
    
        ${basedir}/../..
    
    
        
        
            com.vaadin.external.google
            android-json
        
        
        
            org.projectlombok
            lombok
            test
        
        
            org.springframework.boot
            spring-boot-test-support
            test
        
    
    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    
                    none

在application.properties中写入相关配置

server.port=9000

druid.url=jdbc:mysql://127.0.0.1:3306/test
druid.username=root
druid.password=root
druid.initialSize=1
druid.minIdle=1
druid.maxActive=20
druid.testOnBorrow=true

#springboot默认的日志系统是logback
logging.level.tk.mybatis=TRACE

#freemarker 文件的路径
spring.mvc.view.prefix=/templates/
spring.mvc.view.suffix=.ftl
spring.freemarker.cache=false
spring.freemarker.request-context-attribute=request

#mybatis扫描的文件路径
mybatis.type-aliases-package=tk.yoruo.springboot.model
mybatis.mapper-locations=classpath:mapper/*.xml

#通用mapper的配置
mapper.mappers=tk.yoruo.springboot.util.MyMapper
mapper.not-empty=false
mapper.identity=MYSQL

#mybatis分页插件的配置
pagehelper.helper-dialect=mysql
pagehelper.reasonable=true
pagehelper.support-methods-arguments=true
pagehelper.params=count=countSql

静态资源的路径

用了freemarker模版引擎配置一些静态资源文件路径

package tk.yoruo.springboot.conf;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

/**
 * Created by LXC on 2017/2/9.
 */
@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

    /**
     * spring-boot配置外部静态资源的方法
     *
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
    }
}

其他的service层，实体，controller就不阐述了。

添加数据库配置

创建一个DruidProperties的类

添加一些属性。并加上@ConfigurationProperties(prefix = "druid")注解，告诉boot这个是个读取配置文件的类并且从 application.properties 中取前缀为 druid的value。

接着创建DruidAutoConfiguration类加上@Configuration告诉boot这个是配置类。

注入DruidProperties 并加入@Bean

package tk.yoruo.springboot.druid;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.sql.SQLException;

/**
 * Created by LXC on 2017/2/9.
 */

@Configuration
@EnableConfigurationProperties(DruidProperties.class)
// 对应的类在classpath中有存在时才会注入
@ConditionalOnClass(DruidDataSource.class)

// 对应的前缀和属性名 在classpath中有存在时才会注入
@ConditionalOnProperty(prefix = "druid", name = "url")
public class DruidAutoConfiguration {

    @Autowired
    private DruidProperties druidProperties;

    @Bean
    public DruidDataSource dataSource() {

        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUrl(druidProperties.getUrl());
        druidDataSource.setUsername(druidProperties.getUsername());
        druidDataSource.setPassword(druidProperties.getPassword());
        if (druidProperties.getInitialSize() > 0) {
            druidDataSource.setInitialSize(druidProperties.getInitialSize());
        }
        if (druidProperties.getMinIdle() > 0) {
            druidDataSource.setMinIdle(druidProperties.getMinIdle());
        }
        if (druidProperties.getMaxActive() > 0) {
            druidDataSource.setMaxActive(druidProperties.getMaxActive());
        }
        druidDataSource.setTestOnBorrow(druidProperties.isTestOnBorrow());
        try {
            druidDataSource.init();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        return druidDataSource;
    }
}

接着在src/main/resources目录下新建META-INF文件夹，然后新建spring.factories文件，这个文件用于告诉Spring Boot去找指定的自动配置文件

所以spring.factories内容为

# Auto Configure
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
tk.yoruo.springboot.druid.DruidAutoConfiguration

添加Druid Web监控

分别继承 Druid中的过滤器和servlet。

package tk.yoruo.springboot.druid;

import com.alibaba.druid.support.http.WebStatFilter;

import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;

/**
 * Created by LXC on 2017/2/8.
 */

@WebFilter(filterName = "druidWebStatFilter", urlPatterns = "/*",
        initParams = {
                @WebInitParam(name = "exclusions", value = "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")// 忽略资源
        })
public class DruidStatFilter extends WebStatFilter {

}

package tk.yoruo.springboot.druid;

import com.alibaba.druid.support.http.StatViewServlet;

import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;

/**
 * Created by LXC on 2017/2/8.
 */

@SuppressWarnings("serial")
@WebServlet(urlPatterns = "/druid/*",
        initParams = {
                @WebInitParam(name = "allow", value = "127.0.0.1"),// IP白名单 (没有配置或者为空，则允许所有访问)
//                @WebInitParam(name="deny",value="192.168.16.111"),// IP黑名单 (存在共同时，deny优先于allow)
                @WebInitParam(name = "loginUsername", value = "admin"),// 用户名
                @WebInitParam(name = "loginPassword", value = "admin"),// 密码
                @WebInitParam(name = "resetEnable", value = "true")// 禁用HTML页面上的“Reset All”功能
        })
public class DruidStatViewServlet extends StatViewServlet {

}

注意还需要在Application类上加入 @ServletComponentScan的注解，否则扫描不到你添加的servlet。

package tk.yoruo.springboot;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import tk.yoruo.springboot.util.MyMapper;

/**
 * Created by LXC on 2017/2/9.
 */


@Controller
@ServletComponentScan
@EnableWebMvc
//@ComponentScan(basePackages = {"tk.yoruo.springboot.controller","tk.yoruo.springboot.service"})
@SpringBootApplication
@MapperScan(basePackages = "tk.yoruo.springboot.mapper", markerInterface = MyMapper.class)
public class Application {

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

    @RequestMapping("/")
    String home() {
        return "redirect:countries";
    }

}

注意

Application springboot启动的类，不建议放在顶级的包。例如src/main/java下面。

如果这样做了会和我一样出现这个错误

** WARNING ** : Your ApplicationContext is unlikely to start due to a @ComponentScan of the default package.

如果一定要这样做，需要在Application上加这样的注解。标明你要扫描的包

@ComponentScan(basePackages = {"tk.yoruo.springboot.controller","tk.yoruo.springboot.service"})

这样话静态资源会找不到。

那应该怎么找到... 我还没去试 = =

建议别这样做，放在外面启动服务时间会变久。

欢迎光临我的个人博客