Spring MVC 4 文件下载实例（带源码）

  4.0.0
  com.websystique.springmvc
  Spring4MVCFileDownloadExample
  war
  1.0.0
  Spring4MVCFileDownloadExample Maven Webapp
 
 
     
		4.2.0.RELEASE
	

	
		
			org.springframework
			spring-webmvc
			${springframework.version}
		

		
			javax.servlet
			javax.servlet-api
			3.1.0
		
		
			javax.servlet
			jstl
			1.2
		
	


	
		
			
				
					org.apache.maven.plugins
					maven-compiler-plugin
					3.2
					
						1.7
						1.7
					
				
				
					org.apache.maven.plugins
					maven-war-plugin
					2.4
					
						src/main/webapp
						Spring4MVCFileDownloadExample
						false
					
				
			
		

		Spring4MVCFileDownloadExample

package com.websystique.springmvc.controller;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URLConnection;
import java.nio.charset.Charset;

import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class FileDownloadController {
	
	private static final String INTERNAL_FILE="irregular-verbs-list.pdf";
	private static final String EXTERNAL_FILE_PATH="C:/mytemp/SpringMVCHibernateManyToManyCRUDExample.zip";
	

	@RequestMapping(value={"/","/welcome"}, method = RequestMethod.GET)
	public String getHomePage(ModelMap model) {
		return "welcome";
	}

	/*
	 * Download a file from 
	 *   - inside project, located in resources folder.
	 *   - outside project, located in File system somewhere. 
	 */
	@RequestMapping(value="/download/{type}", method = RequestMethod.GET)
	public void downloadFile(HttpServletResponse response, @PathVariable("type") String type) throws IOException {
	
		File file = null;
		
		if(type.equalsIgnoreCase("internal")){
			ClassLoader classloader = Thread.currentThread().getContextClassLoader();
			file = new File(classloader.getResource(INTERNAL_FILE).getFile());
		}else{
			file = new File(EXTERNAL_FILE_PATH);
		}
		
		if(!file.exists()){
			String errorMessage = "Sorry. The file you are looking for does not exist";
			System.out.println(errorMessage);
			OutputStream outputStream = response.getOutputStream();
			outputStream.write(errorMessage.getBytes(Charset.forName("UTF-8")));
			outputStream.close();
			return;
		}
		
		String mimeType= URLConnection.guessContentTypeFromName(file.getName());
		if(mimeType==null){
			System.out.println("mimetype is not detectable, will take default");
			mimeType = "application/octet-stream";
		}
		
		System.out.println("mimetype : "+mimeType);
		
        response.setContentType(mimeType);
        
        /* "Content-Disposition : inline" will show viewable types [like images/text/pdf/anything viewable by browser] right on browser 
            while others(zip e.g) will be directly downloaded [may provide save as popup, based on your browser setting.]*/
        response.setHeader("Content-Disposition", String.format("inline; filename=\"" + file.getName() +"\""));

        
        /* "Content-Disposition : attachment" will be directly download, may provide save as popup, based on your browser setting*/
        //response.setHeader("Content-Disposition", String.format("attachment; filename=\"%s\"", file.getName()));
        
        response.setContentLength((int)file.length());

		InputStream inputStream = new BufferedInputStream(new FileInputStream(file));

        //Copy bytes from source to destination(outputstream in this example), closes both streams.
        FileCopyUtils.copy(inputStream, response.getOutputStream());
	}

}

package com.websystique.springmvc.configuration;
 
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;
 
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.websystique.springmvc")
public class HelloWorldConfiguration extends WebMvcConfigurerAdapter{
 
     
    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setViewClass(JstlView.class);
        viewResolver.setPrefix("/WEB-INF/views/");
        viewResolver.setSuffix(".jsp");
        registry.viewResolver(viewResolver);
    }
     
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("/static/");
    }
 
}

package com.websystique.springmvc.configuration;
 
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
 
public class HelloWorldInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
  
 
    @Override
    protected Class[] getRootConfigClasses() {
        return new Class[] { HelloWorldConfiguration.class };
    }
   
    @Override
    protected Class[] getServletConfigClasses() {
        return null;
    }
   
    @Override
    protected String[] getServletMappings() {
        return new String[] { "/" };
    }
  
 }

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

 

    
    Spring 4 MVC File Download Example
    
    


    
        Welcome to FileDownloader Example
         
        Click on below links to see FileDownload in action.


         
         
        Download This File (located inside project)  
        

        Download This File (located outside project, on file system)