CommonsMultipartFile接收不了图片文件

来源:4-13 前后端联调验证整体模块功能

火水哥

2019-07-23

图片描述CommonsMultipartFile shopImg = null;//接收图片的对象
CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver(
request.getSession().getServletContext()
);//文件上传解析器,解析request里面的文件信息:通过本次会话当中的上下文去获取相关文件上传的内容

    if (commonsMultipartResolver.isMultipart(request)) {//判断request里面是否有上传的文件流
        MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
        shopImg = (CommonsMultipartFile) multipartHttpServletRequest.getFile("shopImg");//获取图片


    } else {
        modelMap.put("success", false);
        modelMap.put("errMsg", "上传图片不能为空");
        return modelMap;
    }![图片描述](http://img1.sycdn.imooc.com/szimg/5d3690ad09de840209840562.jpg)
    ![图片描述](http://img.mukewang.com/szimg/5d36c11709dca14507930248.jpg)
    老师前台shopImg有数据,我后台用request.getParameter(shopImg)取值为null,
    request.getParameter(verifyCodeActual)取验证码的有值,这个问题弄了一个晚上和一个上午没弄明白,配置文件我是用@Configuration在里面注册bean写的
    @Bean(value = "multipartResolver")
public MultipartResolver multipartResolver(){
    CommonsMultipartResolver resolver = new CommonsMultipartResolver();
    resolver.setDefaultEncoding("UTF-8");
    //resolveLazily属性启用是为了推迟文件解析,以在在UploadAction中捕获文件大小异常
    resolver.setResolveLazily(true);
    resolver.setMaxInMemorySize(40960);
    //上传文件大小 50M 50*1024*1024
    resolver.setMaxUploadSize(50*1024*1024);
    return resolver;
}
写回答

3回答

翔仔

2019-07-24

2.0里面是这样的

package com.imooc.o2o.config.web;

import javax.servlet.ServletException;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

import com.google.code.kaptcha.servlet.KaptchaServlet;
import com.imooc.o2o.interceptor.shopadmin.ShopLoginInterceptor;
import com.imooc.o2o.interceptor.shopadmin.ShopPermissionInterceptor;
import com.imooc.o2o.interceptor.superadmin.SuperAdminLoginInterceptor;

/**
 * 开启Mvc,自动注入spring容器。 WebMvcConfigurerAdapter:配置视图解析器
 * 当一个类实现了这个接口(ApplicationContextAware)之后,这个类就可以方便获得ApplicationContext中的所有bean
 * 
 * @author xiangze
 *
 */
@Configuration
// 等价于<mvc:annotation-driven/>
@EnableWebMvc
public class MvcConfiguration implements WebMvcConfigurer, ApplicationContextAware {
	// Spring容器
	private ApplicationContext applicationContext;

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		this.applicationContext = applicationContext;
	}

	/**
	 * 静态资源配置
	 * 
	 * @param registry
	 */
	@Override
	public void addResourceHandlers(ResourceHandlerRegistry registry) {
		// registry.addResourceHandler("/resources/**").addResourceLocations("classpath:/resources/");
		registry.addResourceHandler("/upload/**").addResourceLocations("file:/Users/baidu/work/image/upload/");
	}

	/**
	 * 定义默认的请求处理器
	 */
	@Override
	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
		configurer.enable();
	}

	/**
	 * 创建viewResolver
	 * 
	 * @return
	 */
	@Bean(name = "viewResolver")
	public ViewResolver createViewResolver() {
		InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
		// 设置Spring 容器
		viewResolver.setApplicationContext(this.applicationContext);
		// 取消缓存
		viewResolver.setCache(false);
		// 设置解析的前缀
		viewResolver.setPrefix("/WEB-INF/html/");
		// 设置试图解析的后缀
		viewResolver.setSuffix(".html");
		return viewResolver;
	}

	/**
	 * 文件上传解析器
	 * 
	 * @return
	 */
	@Bean(name = "multipartResolver")
	public CommonsMultipartResolver createMultipartResolver() {
		CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
		multipartResolver.setDefaultEncoding("utf-8");
		// 1024 * 1024 * 20 = 20M
		multipartResolver.setMaxUploadSize(20971520);
		multipartResolver.setMaxInMemorySize(20971520);
		return multipartResolver;
	}

	@Value("${kaptcha.border}")
	private String border;

	@Value("${kaptcha.textproducer.font.color}")
	private String fcolor;

	@Value("${kaptcha.image.width}")
	private String width;

	@Value("${kaptcha.textproducer.char.string}")
	private String cString;

	@Value("${kaptcha.image.height}")
	private String height;

	@Value("${kaptcha.textproducer.font.size}")
	private String fsize;

	@Value("${kaptcha.noise.color}")
	private String nColor;

	@Value("${kaptcha.textproducer.char.length}")
	private String clength;

	@Value("${kaptcha.textproducer.font.names}")
	private String fnames;

	/**
	 * 由于web.xml不生效了,需要在这里配置Kaptcha验证码Servlet
	 */
	@Bean
	public ServletRegistrationBean<KaptchaServlet> servletRegistrationBean() throws ServletException {
		ServletRegistrationBean<KaptchaServlet> servlet = new ServletRegistrationBean<KaptchaServlet>(new KaptchaServlet(), "/Kaptcha");
		servlet.addInitParameter("kaptcha.border", border);// 无边框
		servlet.addInitParameter("kaptcha.textproducer.font.color", fcolor); // 字体颜色
		servlet.addInitParameter("kaptcha.image.width", width);// 图片宽度
		servlet.addInitParameter("kaptcha.textproducer.char.string", cString);// 使用哪些字符生成验证码
		servlet.addInitParameter("kaptcha.image.height", height);// 图片高度
		servlet.addInitParameter("kaptcha.textproducer.font.size", fsize);// 字体大小
		servlet.addInitParameter("kaptcha.noise.color", nColor);// 干扰线的颜色
		servlet.addInitParameter("kaptcha.textproducer.char.length", clength);// 字符个数
		servlet.addInitParameter("kaptcha.textproducer.font.names", fnames);// 字体
		return servlet;
	}

}

不知道能否帮到同学

0
4
翔仔
回复
火水哥
如果不按照课程来的话,咱们环境不一致,也没法帮同学去定位解决问题呢,同学看看是不是有别的文件上传控件能处理这类问题
2019-07-24
共4条回复

翔仔

2019-07-23

同学好,首先接收shopImg的方式不对,我在Springmvc里,是通过如下方式接收的

CommonsMultipartFile shopImg = null;
		CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver(
				request.getSession().getServletContext());
		if (commonsMultipartResolver.isMultipart(request)) {
			MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
			shopImg = (CommonsMultipartFile) multipartHttpServletRequest.getFile("shopImg");
		} else {
			modelMap.put("success", false);
			modelMap.put("errMsg", "上传图片不能为空");
			return modelMap;
		}

其次,同学在Springboot里面这样的配置方式不知道springboot会不会加载,

可以试试这个

https://blog.csdn.net/linzhiqiang0316/article/details/77016997

springboot我没做过尝试,同学可以尝试一下

0
1
火水哥
老师还是不行,依旧是空,后期这个技术会替换掉吗
2019-07-24
共1条回复

黑白_

2019-07-23

同学,你是不是没有配置文件上传解析器啊

<!-- 文件上传解析器 -->

<bean id="multipartResolver"

    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">

    <property name="defaultEncoding" value="utf-8"></property>

    <!-- 1024 * 1024 * 20 = 20M -->

    <property name="maxUploadSize" value="20971520"></property>

    <property name="maxInMemorySize" value="20971520"></property>

</bean>


0
3
Simon___
回复
火水哥
同学你好,我遇到了和你一样的问题,能给我看看你Conroller图片上传那段代码怎么写的吗,谢谢~
2019-10-21
共3条回复

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