WebMvcConfigurer接口使用——閱讀開源項目中的代碼

 作用：功能等同於原來的springMVC.xml。可以注冊視圖解析器，多部件解析器

 示例：　　主配置類實現WebMvcConfigurer接口。

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.config.annotation.*;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc　　　　　　//開啟支持webMVC
@ComponentScan("com.yrc.fileuplod")
public class MVCConfig  implements WebMvcConfigurer {

    //配置內置解析器
    @Bean
    public InternalResourceViewResolver viewResolver(){
        InternalResourceViewResolver viewResolve = new InternalResourceViewResolver();
        viewResolve.setPrefix("/WEB-INF/classes/views");
        viewResolve.setSuffix(".jsp");
        viewResolve.setViewClass(JstlView.class);
        return viewResolve;
    }

　　//配置多部件解析器
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver resolver = new CommonsMultipartResolver();
        resolver.setMaxUploadSize(1000000);
        return resolver;
    }

    /*
    視圖跳轉控制器
     */
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/index").setViewName("/index");
    }
}

 參考博客：https://www.cnblogs.com/sueyyyy/p/11608900.html

 

 

補充1：springboot下啟動web工程，不建立Main方法。

 

　　步驟1：主配置實現WebMvcConfigurer接口。略

 

　　步驟2：定義web初始化類，功能等同於web.xml。需要實現WebApplicationInitializer接口

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;

public class WebInit implements WebApplicationInitializer {
    
    //啟動初始化
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        //注冊springMVC配置
        context.register(MVCConfig.class);
        //設置servletContext上下文
        context.setServletContext(servletContext);
        
        
        ServletRegistration.Dynamic servlet =servletContext.addServlet("dispatcher",new DispatcherServlet(context));
        //設置映射規則
        servlet.addMapping("/");
        
        //設置啟動權限
        servlet.setLoadOnStartup(1);


    }
}

WebApplicationInitializer詳解：

　　參考博客：https://blog.csdn.net/zq17865815296/article/details/79464403

 

　　步驟3：建立控制器

　　

import org.apache.commons.io.FileUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;

/**
 * Created by sang on 16-12-16.
 */
@Controller
public class UploadController {
    @ResponseBody
    @RequestMapping(value = "/upload",method = RequestMethod.POST,produces = "text/plain;charset=UTF-8")
    public String upload(MultipartFile file) {
        try {
            FileUtils.writeByteArrayToFile(new File("/home/sang/workspace/"+file.getOriginalFilename()),file.getBytes());
            return "上傳成功";
        } catch (IOException e) {
            e.printStackTrace();
            return "上傳失敗";
        }
    }
}

 

 補充2：案例為實現文件上傳，在不實現main方法的前提下，想啟動web工程需要將工程的打包方式設置為war。