Spring Boot：文件下载

标签：文件 Spring boot springframework Boot org os 下载

测试代码

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.2</version>
    </parent>

    <packaging>jar</packaging>

    <groupId>com.kaven</groupId>
    <artifactId>springboot</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>springboot</name>
    <description>springboot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

文件下载接口：

package com.kaven.springboot.controller;

import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletResponse;
import java.io.*;

@RestController
public class FilesController {

    @GetMapping("/download/{path}")
    public void download(@PathVariable("path") String path ,
                         HttpServletResponse response){
        // 将需要下载的文件对应到服务器的本地文件路径
        // 一般会使用云存储服务器来存储文件，然后数据库中保存云存储服务器中文件的路径
        File file = new File("C:\\Users\\Kaven\\Desktop\\images\\" + path);
        // 缓冲字节数组
        byte[] buffer = new byte[1024];
        BufferedInputStream bis = null;
        OutputStream os = null;
        try {
            // 文件是否存在
            if (file.exists()) {
                // 设置响应
                response.setContentType("application/octet-stream;charset=UTF-8");
                response.setCharacterEncoding("UTF-8");
                // 获取响应的输出流
                os = response.getOutputStream();
                // 获取文件的输入流
                bis = new BufferedInputStream(new FileInputStream(file));
                // 不断将文件输入流中的字节读取到缓冲字节数组中，直到文件读取完
                while(bis.read(buffer) != -1){
                    // 将缓冲字节数组中的字节写入响应的输出流
                    os.write(buffer);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // 关闭资源
                if(bis != null) {
                    bis.close();
                }
                if(os != null) {
                    os.flush();
                    os.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

启动类：

package com.kaven.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootApplication {

    public static void main(String[] args) {
        SpringApplication application = new SpringApplication(SpringbootApplication.class);
        application.run(args);
    }
}

使用浏览器进行测试，下载的文件在服务器上存在，如下图所示。

Spring Boot：文件下载_spring boot