springbooot

Srpingboot记录

一、HelloWorld

依赖

<parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.5.9.RELEASE</version>

    </parent>

    <dependencies>

      <!—SpringBoot web 组件 -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

    </dependencies>

spring-boot-starter-parent作用

在pom.xml中引入spring-boot-start-parent,spring官方的解释叫什么stater poms,它可以提供dependency management,也就是说依赖管理，引入以后在申明其它dependency的时候就不需要version了，后面可以看到。

spring-boot-starter-web作用

springweb 核心组件

创建HelloController类，内容如下

 

@RestController

@EnableAutoConfiguration

publicclass HelloController {

     @RequestMapping("/hello")

     public String index() {

          return"Hello World";

     }   

publicstaticvoid main(String[] args) {

          SpringApplication.run(HelloController.class, args);

     }

}

2.4、@RestController

在上加上RestController 表示修饰该Controller所有的方法返回JSON格式,直接可以编写

Restful接口

2.5、@EnableAutoConfiguration

注解:作用在于让 Spring Boot   根据应用所声明的依赖来对 Spring 框架进行自动配置
        这个注解告诉Spring Boot根据添加的jar依赖猜测你想如何配置Spring。由于spring-boot-starter-web添加了Tomcat和Spring MVC，所以auto-configuration将假定你正在开发一个web应用并相应地对Spring进行设置。

2.6 SpringApplication.run(HelloController.class, args);

   标识为启动类

2.7、SpringBoot启动方式1

Springboot默认端口号为8080

 

@RestController

@EnableAutoConfiguration

publicclass HelloController {

     @RequestMapping("/hello")

     public String index() {

          return"Hello World";

     }   

publicstaticvoid main(String[] args) {

          SpringApplication.run(HelloController.class, args);

     }

}

启动主程序，打开浏览器访问http://localhost:8080/index，可以看到页面输出Hello World

2.8、SpringBoot启动方式2

@ComponentScan(basePackages = "com.itmayiedu.controller")---控制器扫包范围

@ComponentScan(basePackages = "com.itmayiedu.controller")

@EnableAutoConfiguration

public class App {

      public static void main(String[] args) {

            SpringApplication.run(App.class, args);

      }

}

说明：@RestController登陆Controller+Responsebody，用原生的SpringMVC也是可以的！

二、静态资源访问

在src/main/resources/目录下创建如下规定的目录：

/static

/public

/resources

/META-INF/resources

这是springboot已经配置好了的静态资源映射。注意：路径是不带static或者public的，已经映射好了。

三、自定义异常拦截器

1.拦截器代码（跟SpringMVC相同）

package com.loger.interceptor;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONObject;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.PrintWriter;

/**

 * Create by Loger

 * SpringMVC拦截器

 */

public class ExceptionInterceptor implements HandlerInterceptor {

    public boolean preHandle(HttpServletRequest request,

                             HttpServletResponse response, Object handler) throws Exception {

        return true;

    }

    public void postHandle(HttpServletRequest request,

                           HttpServletResponse response, Object handler,

                           ModelAndView modelAndView) throws Exception {

    }

    public void afterCompletion(HttpServletRequest request,

                                HttpServletResponse response, Object handler, Exception ex)

            throws Exception {

        JSONObject msg = new JSONObject();

        if (ex != null) {

            msg.put("result", "fail");

            msg.put("code", "system.error");

            msg.put("msg", "系统错误");

            String json = JSON.toJSONString(msg);

            response.setContentType("application/json;charset=UTF-8");

            response.setHeader("Pragma", "No-cache");

            response.setHeader("Cache-Control", "no-cache");

            response.setDateHeader("Expires", 0);

            PrintWriter out = response.getWriter();

            out.print(json);

            out.flush();

            out.close();

        }

    }

} 

2.拦截器配置

@Configuration

public class WebConfig extends WebMvcConfigurerAdapter {

    @Override

    public void addInterceptors(InterceptorRegistry registry) {

        registry.addInterceptor(new ExceptionInterceptor());

        super.addInterceptors(registry);

    }

}

3.main方法扫包

@ComponentScan(basePackages = {"com.loger.controller","com.loger.common"})

@EnableAutoConfiguration//标识为启动类

public class Main {

    public static void main(String [] args){

        SpringApplication.run(Main.class,args);

    }

}

说明：扫描到config所在的包

四、springboot中使用原生Servlet的东西

1.过滤器

@WebFilter(filterName = "test",urlPatterns = "/*")

public class TestFilter implements Filter {

    @Override

    public void init(FilterConfig filterConfig) throws ServletException {

        System.out.println("过滤器被初始化了");

    }

    @Override

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;

        StringBuffer requestURL = request.getRequestURL();

        System.out.println("请求的url："+requestURL);

        filterChain.doFilter(servletRequest,servletResponse);

    }

    @Override

    public void destroy() {

        System.out.println("过滤器被销毁了");

    }

}

2.监听器

@WebListener

public class TestListener implements ServletRequestListener {

    @Override

    public void requestDestroyed(ServletRequestEvent servletRequestEvent) {

        System.out.println("请求销毁了了:"+servletRequestEvent.getServletRequest().getRemoteAddr());

    }

    @Override

    public void requestInitialized(ServletRequestEvent servletRequestEvent) {

        System.out.println("请求进来了:"+servletRequestEvent.getServletRequest().getRemoteAddr());

    }

}

3.servlet

@WebServlet(value = "/testServlet")

public class TestServlet extends HttpServlet {

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        System.out.println("请求了TestServlet");

        resp.setCharacterEncoding("utf-8");

        PrintWriter out = resp.getWriter();

        out.print("响应给你");

    }

}

4.扫包

@ServletComponentScan(basePackages = {"com.loger.filter","com.loger.listener","com.loger.servlet"})

@ComponentScan(basePackages = {"com.loger.controller","com.loger.common"})

@EnableAutoConfiguration//标识为启动类

public class Main {

    public static void main(String [] args){

        SpringApplication.run(Main.class,args);

    }

}

五、项目路径问题

@RequestMapping(value = "/path")

    public Object path(HttpServletRequest request){

        //这种写法springboot不支持

//        String path = this.getClass().getClassLoader().getResource("/").getPath();

//        System.out.println(path);

        return request.getServletContext().getRealPath("/");

    }

不支持this这种写法

六、页面（freeMark）

推荐使用freeMark，不推荐使用jsp。如果使用jsp，那就需要建立webapps、web-inf目录，这跟web工程就没什么区别了。

1.依赖

<!-- 引入freeMarker的依赖包. -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-freemarker</artifactId>

        </dependency>

2.配置文件

新建application.properties文件，在resources目录下

#freeMark配置

spring.freemarker.allow-request-override=false

spring.freemarker.cache=true

spring.freemarker.check-template-location=true

spring.freemarker.charset=UTF-8

spring.freemarker.content-type=text/html

spring.freemarker.expose-request-attributes=false

spring.freemarker.expose-session-attributes=false

spring.freemarker.expose-spring-macro-helpers=false

spring.freemarker.suffix=.ftl

spring.freemarker.template-loader-path=classpath:/templates/

3.代码

@RequestMapping

    public String index(HttpServletRequest request){

        request.setAttribute("name","Loger");

        return "index";

    }

4.页面

<!DOCTYPE html>

<html>

<head lang="en">

    <meta charset="UTF-8"/>

    <title>ftl页面</title>

</head>

<body>

${name}

</body>

</html>

七、文件上传

1.单文件上传

/**

     * 单文件上传

     * @param file2

     * @return

     */

    @RequestMapping(value = "/upload",method = RequestMethod.POST)

    public Object upload(MultipartFile file2){

        //说明：使用MultipartFIle不需要进行配置，使用CommonsMultipartFile是需要配置的

        //参数名可以与文件name属性对应，也可以使用@RequestParam指定

        File save = new File("D:\"+file2.getOriginalFilename());

        try {

            System.out.println(file2.getName()+" "+file2.getOriginalFilename());

            file2.transferTo(save);

        } catch (IOException e) {

            e.printStackTrace();

            return "fail";

        }

        return "success";

    }

2.多文件上传

/**

     * 多文件上传

     * @return

     */

    @RequestMapping(value = "/upload2",method = RequestMethod.POST)

    public Object upload2(HttpServletRequest request){

        List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");//这个file对应表单名

        for(MultipartFile file:files){

            File save = new File("d:\"+file.getOriginalFilename());

            try {

                file.transferTo(save);

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

        return "success";

    }

3.页面代码

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

你能访问到我吗？？？

<form action="/upload2" method="post" enctype="multipart/form-data" >

    <input name="file" type="file"><br>

    <input name="file" type="file"><br>

    <input name="file" type="file"><br>

    <input type="submit" value="上传">

</form>

</body>

</html>

4.上传文件大小限制配置

在application.properties文件中添加如下配置

#文件上传设置

spring.http.multipart.maxFileSize=100Mb

spring.http.multipart.maxRequestSize=1000Mb

八、整合jdbc-template

依赖

<!-- jdbc-template -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-jdbc</artifactId>

        </dependency>

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.21</version>

        </dependency>

application.properties配置

#JDBCTemplate

spring.datasource.url=jdbc:mysql://localhost:3306/db_test

spring.datasource.username=root

spring.datasource.password=apple

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

增删改

都是使用jdbcTemplate.unpdate()；方法

public void delete(int id){

    jdbcTemplate.update("DELETE FROM `user` WHERE id=?;",id);

}

查

首先需要一个Mapper映射：

然后使用query方法：

事务管理

在Service方法上加@Transactional注解即可。

springboot整合Mybatis

依赖

<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->

        <dependency>

            <groupId>org.mybatis.spring.boot</groupId>

            <artifactId>mybatis-spring-boot-starter</artifactId>

            <version>1.3.1</version>

        </dependency>

数据源

跟jdbctemplate的数据源一样的

#Mybatis

spring.datasource.url=jdbc:mysql://localhost:3306/db_test

spring.datasource.username=root

spring.datasource.password=apple

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

mapper接口

这里使用注解的形式

public interface UserMapper {

    @Select("select id,name,age from user where id=#{id}")

    User select(Integer id);

}

启动类扫包

扫描mapper接口所在的包

@MapperScan(value = "com.loger.mapper")

打包发布

在pom文件中添加：

<build>

        <plugins>

            <plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <configuration>

                    <source>1.8</source>

                    <target>1.8</target>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

                <configuration>

                    <maimClass>com.loger.main.Main</maimClass>

                </configuration>

                <executions>

                    <execution>

                        <goals>

                            <goal>repackage</goal>

                        </goals>

                    </execution>

                </executions>

 

            </plugin>

        </plugins>

    </build>