Java实现生成文件并将文件下载至浏览器默认路径的方法

逃离我推掉我的手 2023-01-23 03:51 2阅读 0赞

## 一、生成文件 ##

### 1.1 生成word文件 ###

/**
         * 生成 word 文件
         *
         * @param dataMap 待填充数据
         * @param templateName 模板文件名称
         * @param filePath 模板文件路径
         * @param fileName 生成的 word 文件名称
         */
        public static void createWord(Map dataMap, String templateName, String filePath, String fileName){ 
            // 创建配置实例
            Configuration configuration = new Configuration(Configuration.VERSION_2_3_28);
            // 设置编码
            configuration.setDefaultEncoding(StandardCharsets.UTF_8.name());
            // ftl模板文件
            configuration.setClassForTemplateLoading(ActionController.class, filePath);
    
            try { 
                // 获取模板
                Template template = configuration.getTemplate(templateName);
    //            response.setHeader("Content-disposition",
    //                    "attachment;filename=" + URLEncoder.encode(fileName + ".doc", StandardCharsets.UTF_8.name()));
    //             定义输出类型
    //            response.setContentType("application/msword");
    //            Writer out = new BufferedWriter(new OutputStreamWriter(response.getOutputStream()));
    
                File outFile = new File(System.getProperties().getProperty("user.home") + File.separator + "filepath" + File.separator + fileName);
                Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile),"UTF-8"));
    
                // 生成文件
                template.process(dataMap, out);
    
                out.flush();
                out.close();
            } catch (Exception e){ 
                e.printStackTrace();
            }
        }

### 1.2 生成json文件 ###

FileUtil是文件工具类，使用createNewFile方法可以生成json文件

package com.umetrip.qa.utils;
    
    import com.alibaba.fastjson.JSONObject;
    import org.springframework.core.io.FileSystemResource;
    import org.springframework.core.io.InputStreamResource;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.net.URLEncoder;
    
    /**
     * @description:
     * @author: 孙东平
     * @time: 2020-10-28 11:42
     */
    public class FileUtil { 
        public static void createNewFile(String fileName, Object data) throws Exception{ 
            //1、创建文件对象
            File tempFile = new File(System.getProperties().getProperty("user.home") + File.separator + "filepath" + File.separator + fileName);
            File fileParent = tempFile.getParentFile();
            String fileParentPath = tempFile.getParent();
            System.out.println("fileParent:" + fileParent);
            System.out.println("fileParentPath:" + fileParentPath);
    
            //2、判断目录或文件是否存在
            if (!fileParent.exists()) { 
                fileParent.mkdirs();// 能创建多级目录
            }
            if (!tempFile.exists())
                tempFile.createNewFile();//有路径才能创建文件
            System.out.println(tempFile);
    
            String path = tempFile.getPath();
            String absolutePath = tempFile.getAbsolutePath();//得到文件/文件夹的绝对路径
            String getFileName = tempFile.getName();//得到文件/文件夹的名字
            System.out.println("path:"+path);
            System.out.println("absolutePath:"+absolutePath);
            System.out.println("getFileName:"+getFileName);
    
            //3、写入数据
            FileOutputStream fos = new FileOutputStream(System.getProperties().getProperty("user.home") + File.separator + "filepath" + File.separator + fileName);
            String dataStr = JSONObject.toJSONString(data);
            byte[] bytes = dataStr.getBytes();
            fos.write(bytes);
            fos.close();
        }
    //
    //    public static void createNewFile(String fileName, Object data) throws Exception{ 
    //        //1、创建文件对象
    //        File tempFile = new File(System.getProperties().getProperty("user.home") + File.separator + "filepath" + File.separator + fileName);
    //        File fileParent = tempFile.getParentFile();
    //        String fileParentPath = tempFile.getParent();
    //        System.out.println("fileParent:" + fileParent);
    //        System.out.println("fileParentPath:" + fileParentPath);
    //
    //        //2、判断目录或文件是否存在
    //        if (!fileParent.exists()) { 
    //            fileParent.mkdirs();// 能创建多级目录
    //        }
    //        if (!tempFile.exists())
    //            tempFile.createNewFile();//有路径才能创建文件
    //        System.out.println(tempFile);
    //
    //        String path = tempFile.getPath();
    //        String absolutePath = tempFile.getAbsolutePath();//得到文件/文件夹的绝对路径
    //        String getFileName = tempFile.getName();//得到文件/文件夹的名字
    //        System.out.println("path:"+path);
    //        System.out.println("absolutePath:"+absolutePath);
    //        System.out.println("getFileName:"+getFileName);
    //
    //        //3、写入数据
    //        FileOutputStream fos = new FileOutputStream(System.getProperties().getProperty("user.home") + File.separator + "filepath" + File.separator + fileName);
    //        String dataStr = JSONObject.toJSONString(data);
    //        byte[] bytes = dataStr.getBytes();
    //        fos.write(bytes);
    //        fos.close();
    //    }
    
        /**
         * 文件下载
         * @param file
         * @throws IOException
         */
        public static ResponseEntity<InputStreamResource> downloadFile(File file) throws IOException { 
            if (file.exists()) { 
                FileSystemResource fileSource = new FileSystemResource(file);
                return downloadFile(fileSource.getInputStream(),fileSource.getFilename());
            }
            return null;
        }
        public static ResponseEntity<InputStreamResource> downloadFile(InputStream in, String fileName) { 
            try { 
                byte[] testBytes = new byte[in.available()];
                HttpHeaders headers = new HttpHeaders();
                headers.add("Access-Control-Expose-Headers", "Content-Disposition");
                headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
                headers.add("Content-Disposition", String.format("attachment; filename=\"%s\"", MarkUtil.convertFileName(fileName)));
                headers.add("Pragma", "no-cache");
                headers.add("Expires", "0");
                return ResponseEntity
                        .ok()
                        .headers(headers)
                        .contentLength(testBytes.length)
                        .contentType(MediaType.parseMediaType("application/octet-stream"))
                        .body(new InputStreamResource(in));
            } catch (IOException e) { 
                e.printStackTrace();
            }
            return null;
        }
    }

MarkUtil类

package com.umetrip.qa.utils;
    
    import org.apache.commons.lang.StringUtils;
    
    import java.io.UnsupportedEncodingException;
    import java.net.URLEncoder;
    
    /**
     * @description:
     * @author: 孙东平
     * @time: 2021-07-05 16:06
     */
    public class MarkUtil { 
        /**
         * chinese code convert
         * @param fileName
         * @return
         */
        public static String convertFileName(String fileName) { 
            System.out.println("fileName before: " + fileName);
            if(!StringUtils.isBlank(fileName)) { 
                try { 
                    fileName = URLEncoder.encode(fileName, "UTF-8");
                } catch (UnsupportedEncodingException e) { 
                    e.printStackTrace();
                }
            }
            System.out.println("fileName after: " + fileName);
            return fileName;
        }
    }

## 二、下载文件 ##

### 2.1 方式一 ###

使用 1.2 中 FileUtil的 downloadFile 方法

### 2.2 方式二 ###

package com.taobao.rigel.rap.utils;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.*;
    import java.net.URLEncoder;
    
    /**
     * @description:  将文件内容响应到浏览器
     * @author: 孙东平
     * @time: 2021-07-05 16:53
     */
    public class DownloadUtil { 
        // 字符编码格式
        private static String charsetCode = "utf-8";
    
        /**
         * 文件的内容类型
         */
        private static String getFileContentType(String name){ 
            String result = "";
            String fileType = name.toLowerCase();
            if (fileType.endsWith(".png")) { 
                result = "image/png";
            } else if (fileType.endsWith(".gif")) { 
                result = "image/gif";
            } else if (fileType.endsWith(".jpg") || fileType.endsWith(".jpeg")) { 
                result = "image/jpeg";
            } else if(fileType.endsWith(".svg")){ 
                result = "image/svg+xml";
            }else if (fileType.endsWith(".doc")) { 
                result = "application/msword";
            } else if (fileType.endsWith(".xls")) { 
                result = "application/x-excel";
            } else if (fileType.endsWith(".zip")) { 
                result = "application/zip";
            } else if (fileType.endsWith(".pdf")) { 
                result = "application/pdf";
            } else { 
                result = "application/octet-stream";
            }
            return result;
        }
    
    
        /**
         * 下载文件
         * @param path 文件的位置
         * @param fileName 自定义下载文件的名称
         * @param resp http响应
         * @param req http请求
         */
        public static void downloadFile(String path, String fileName, HttpServletResponse resp, HttpServletRequest req){ 
    
            try { 
                File file = new File(path);
                /**
                 * 中文乱码解决
                 */
                String type = req.getHeader("User-Agent").toLowerCase();
                System.out.println("type:" + type);
                if(type.indexOf("firefox")>0 || type.indexOf("chrome")>0){ 
                    /**
                     * 谷歌或火狐
                     */
    //                fileName = new String(fileName.getBytes(charsetCode), "iso8859-1");
    //                fileName = new String(fileName.getBytes(charsetCode), "utf-8");
                    fileName = URLEncoder.encode(fileName, charsetCode);
                }else{ 
                    /**
                     * IE
                     */
                    fileName = URLEncoder.encode(fileName, charsetCode);
                }
                // 设置响应的头部信息
                resp.setHeader("content-disposition", "attachment;filename=" + fileName);
                // 设置响应内容的类型
                System.out.println("getFileContentType(fileName):" + getFileContentType(fileName));
                resp.setContentType(getFileContentType(fileName)+"; charset=" + charsetCode);
                // 设置响应内容的长度
                resp.setContentLength((int) file.length());
                // 输出
                outStream(new FileInputStream(file), resp.getOutputStream());
                System.out.println("resp: " + resp.toString());
            } catch (Exception e) { 
                System.out.println("执行downloadFile发生了异常：" + e.getMessage());
            }
        }
    
    
    
        /**
         * 基础字节数组输出
         */
        private static void outStream(InputStream is, OutputStream os) { 
            try { 
                byte[] buffer = new byte[10240];
                int length = -1;
                while ((length = is.read(buffer)) != -1) { 
                    os.write(buffer, 0, length);
                    os.flush();
                }
            } catch (Exception e) { 
                System.out.println("执行 outStream 发生了异常：" + e.getMessage());
            } finally { 
                try { 
                    os.close();
                } catch (IOException e) { 
                }
                try { 
                    is.close();
                } catch (IOException e) { 
                }
            }
        }
    }

## 三、前端代码处理 ##

当调好后端接口后，前端代码也需要进行相应的处理

export default { 
      name: 'ApiPortType',
      data () { 
        return { 
          visible: false,
          radioType: 'doc',
          id: ''
        }
      },
      methods: { 
        handleSubmit (e) { 
          console.log(this.id)
          console.log(this.radioType)
          console.log('可以调接口了！！')
          console.log('工程名：' + this.$store.state.projectName)
          generateDocumentOfApi({ projectName: this.$store.state.projectName, actionId: this.id, type: this.radioType}).then((res) => { // generateDocumentOfApi({id: '1535331', type: this.radioType}).then((res) => { let data = res.data let contentDisposition = res.headers['content-disposition'] let fileName = contentDisposition.substring(contentDisposition.indexOf('"') + 1, contentDisposition.length - 1) console.log(fileName) console.log(decodeURIComponent(fileName))
            this.download(data, decodeURIComponent(fileName))
            console.log('调结束generateDocumentOfApi接口，去查看吧！！！！')
          })
        },
        // 下载文件
        download (data, fileName) { 
          if (!data) { 
            return
          }
          let type = fileName.split('.')[1]
          console.log('type:' + type)
          let url
          if (type === 'json') { 
            // type: 'application/json'
            url = window.URL.createObjectURL(new Blob([JSON.stringify(data)]), { type: 'application/json'})
    
            // // encodeURIComponent解决中文乱码
            // let uri = 'data:text/csv;charset=utf-8,\ufeff' + encodeURIComponent(JSON.stringify(data))
            // // 通过创建a标签实现
            // let link = document.createElement('a')
            // link.href = uri
            // // 对下载的文件命名
            // link.download = '地区数据表.json'
            // document.body.appendChild(link)
            // link.click()
            // document.body.removeChild(link)
          } else if (type === 'doc') { 
            url = window.URL.createObjectURL(new Blob([data]), { type: 'application/msword'})
          }
          console.log('url: ' + url)
          let link = document.createElement('a')
          link.style.display = 'none'
          link.href = url
          link.download = fileName
          // link.setAttribute('download', fileName)
          // document.body.appendChild(link)
          link.click()
          window.URL.revokeObjectURL(url)
        }
      }
    }

效果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM0MjQxODYx_size_16_color_FFFFFF_t_70]

## 四、解决url中文乱码问题 ##

**后端**使用`URLEncoder.encode(fileName, "UTF-8");`编码  
**前端**使用如下方式解码即可

// 解码用 
    decodeURIComponent(str)
    // 编码用 
    encodeURIComponent(str)

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM0MjQxODYx_size_16_color_FFFFFF_t_70]: /images/20221004/e5d0d8df8e98495fa6c74131680f2899.png