jsp开发之文件下载

Myth丶恋晨 2022-03-15 02:52 214阅读 0赞

# 步骤如下： #

1、写一个jsp页面。（就写一个连接就行了）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 1][]

2，配置web.xml(前端我利用的是springMVC)

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 2][]

3、导入jar包（我利用的是maven注入）

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>com.nfha.wyz</groupId>
      <artifactId>wyz</artifactId>
      <version>1.0-SNAPSHOT</version>
      <packaging>war</packaging>
    
      <name>wyz Maven Webapp</name>
      
      <url>http://www.example.com</url>
    
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
      </properties>
    
      <dependencies>
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.11</version>
          <scope>test</scope>
        </dependency>
        
        <dependency>
          <groupId>commons-io</groupId>
          <artifactId>commons-io</artifactId>
          <version>2.6</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-beans</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-tx</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context-support</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
    
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-web</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
    
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-webmvc</artifactId>
          <version>4.1.7.RELEASE</version>
        </dependency>
      </dependencies>
    
      <build>
        <finalName>wyz</finalName>
        <pluginManagement>
          <plugins>
            <plugin>
              <artifactId>maven-clean-plugin</artifactId>
              <version>3.1.0</version>
            </plugin>
            
            <plugin>
              <artifactId>maven-resources-plugin</artifactId>
              <version>3.0.2</version>
            </plugin>
            <plugin>
              <artifactId>maven-compiler-plugin</artifactId>
              <version>3.8.0</version>
            </plugin>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <version>2.22.1</version>
            </plugin>
            <plugin>
              <artifactId>maven-war-plugin</artifactId>
              <version>3.2.2</version>
            </plugin>
            <plugin>
              <artifactId>maven-install-plugin</artifactId>
              <version>2.5.2</version>
            </plugin>
            <plugin>
              <artifactId>maven-deploy-plugin</artifactId>
              <version>2.8.2</version>
            </plugin>
          </plugins>
        </pluginManagement>
      </build>
    </project>

4，写aplicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:mvc="http://www.springframework.org/schema/mvc"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd">
        
        <context:component-scan base-package="com.nfha.controller"></context:component-scan>
        
        <mvc:annotation-driven></mvc:annotation-driven>
        
        <mvc:resources location="/files/" mapping="/files/**"></mvc:resources>
    
    </beans>

5,编写controller

package com.*.controller;
    
    import org.apache.commons.io.FileUtils;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import javax.servlet.ServletOutputStream;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.File;
    import java.io.IOException;
    import java.io.PrintWriter;
    @Controller
    public class DemoController {
        @RequestMapping("download")
        public void downlode(String fileName, HttpServletResponse res, HttpServletRequest req)throws IOException {
            System.out.print("进入后台");
            //设置响应流中文件进行下载
            res.setHeader("Content-Disposition", "attachment;filename="+fileName);
            //把二进制流放入到响应体中.
            ServletOutputStream out=res.getOutputStream();
            String path = req.getServletContext().getRealPath("files");
            System.out.println(path);
            File file = new File(path, fileName);
            byte []bytes= FileUtils.readFileToByteArray(file);
            out.write(bytes);
            out.flush();
            out.close();
    
        }
    }

# OK了。就完成了。是不是很简单。下面是效果图。 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 3][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70]: /images/20220315/c6344983fead4c058f443e295eb945aa.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 1]: /images/20220315/a6c173da121043c1bc7fb1859aadd088.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 2]: /images/20220315/751b3ce26cec48979c1074d72e243929.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjgwMTMwNjQw_size_16_color_FFFFFF_t_70 3]: /images/20220315/1ac4d2955fc54870bede1c1110922f72.png