SpringBoot 上传、下载（四）

 

工程目录结构

 

完整代码：

 

1、pom.xml

首先当然是添加依赖，用到thymeleaf模板渲染html页面

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.hello</groupId>
  <artifactId>HelloBoot</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>


  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.1.BUILD-SNAPSHOT</version>
  </parent>
  
  <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
  </dependencies>
  
  <repositories>
    <repository>
        <id>spring-snapshots</id>
        <name>Spring Snapshots</name>
        <url>https://repo.spring.io/libs-snapshot</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
  </repositories>
  
</project>

 

如果遇到<parent>标签报错，看看和上面写的有出入吗---

 

2、application.properties

只有一行，关闭thymeleaf缓存

spring.thymeleaf.cache=false

 

 

3、file.html 页面

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"  
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

    <h1 th:inlines="text">文件上传</h1>
    <form action="fileUpload" method="post" enctype="multipart/form-data">
        <p><input type="file" name="filename" /></p>
        <p><input type="submit" value="提交" /></p>
        
    </form>
    <a href="http://localhost:8080/fileDownload">下载</a>

</body>
</html>

 

 

4、HelloController.java  控制类

 

package com.hello;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

@Controller
public class HelloController {

    //映射视图
    @RequestMapping("/file")
    public String file() {
        return "/file";
    }
    
    //上传
    @RequestMapping("fileUpload")
    @ResponseBody
    public String fileUpload(@RequestParam("filename") MultipartFile file) {
        if(file.isEmpty()) {
            return "false";
        }
        //将里面内容移动到目标文本文档
        File dest = new File("D:/test.txt");
        try {
            file.transferTo(dest); 
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }
    //下载
    @RequestMapping("fileDownload")
    @ResponseBody
    public String fileDownload(HttpServletResponse res) {
        String fileName = "1.jpg";
        res.setHeader("content-type", "application/octet-stream");
        res.setContentType("application/octet-stream");
        res.setHeader("Content-Disposition", "attachment;filename=" + fileName);
        
        byte[] buff = new byte[1024];
        BufferedInputStream bis = null;
        OutputStream os = null;
        try {
            os = res.getOutputStream();
            //获取zhi'ding
            bis = new BufferedInputStream(
                    new FileInputStream(new File("D:/1.jpg")));
            int i = bis.read(buff);
            while(i != -1) {
                //每次读取1024字节，就flush输出
                os.write(buff, 0, buff.length);
                os.flush();
                //然后继续读取下一个1024字节
                i = bis.read(buff);
            }
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
              if (bis != null) {
                  try {
                    bis.close();
                  } catch (IOException e) {
                    e.printStackTrace();
                  }
                }
        }
        return "success";
    }
    
    
}

 

 

（1）file()方法return返回的是视图“file.html”，使用@Controller修饰类即可

（2）上传业务方法fileUpload()，return返回的是个字符串——“false“或”success”，不是html视图页面，所以不用渲染视图，

这里使用@Controller修饰类    和    @ResponseBody修饰方法

 

5、启动类App.java

package com.hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class App {

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

 

 posted on 2018-03-20 18:58  布鲁布鲁sky  阅读(246)  评论(0)  编辑  收藏  举报