根据json生成多个文件并打包压缩提供下载

- 日理万妓 2023-06-07 12:17 2阅读 0赞

首先先创建一个工具类，工具类里提供一个方法根据json字符串生成多个临时文件并打进压缩包，然后删除这些临时文件，返回压缩包下载地址供前端下载。

import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.UUID;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    import com.alibaba.fastjson.JSONArray;
    
    public class FileToZipUtil {
    	
    	/**
    	 * @param txtName       压缩文件内部文件统一命名
    	 * @param jsonString    json字符串，数据结构为数组
    	 * @param rootPath      web项目根目录
    	 * @return
    	 */
    	public String createZipAndReturnPath(String txtName, String jsonString, String rootPath) {
    
    		//生成随机代码防止同时下载时文件名重复
    		String ranStr = "_" + UUID.randomUUID().toString().substring(0,5);
    		
            //生成jsonArray列表
            JSONArray jsonArray = JSONArray.parseArray(jsonString);
            
            //压缩文件内的临时文件名集合，方便生成压缩包后删除
            List<String> tempFiles = new ArrayList<String>();
    
            try {
                //生成的zip临时文件命名
                String zipName = "tempZip_" + ranStr + ".zip";
    
                //zip文件保存路径
                String zipPath = rootPath + zipName;
    
                ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipPath));
    
                //遍历数组，生成压缩文件内部txt文件
                for (int i = 0; i < jsonArray.size(); i++) {
                	
    				//组成文件名
    	            String fileName = txtName + "_" + ranStr + ".txt";
    	            
    	            //获取生成的txt文件完整路径
                    String txtPath = rootPath + fileName;
    	            FileWriter fileWriter = null;
    	    		try {
    	    			fileWriter = new FileWriter(txtPath);
    	    			fileWriter.write(jsonArray.getJSONObject(i).toJSONString());
    	    			fileWriter.flush();
    	    			fileWriter.close();
    	    			tempFiles.add(txtPath);
    	    		} catch (IOException e) {
    	    			e.printStackTrace();
    	    		}
    	            
                    //为压缩文件内部的每个txt文件命名
                    FileInputStream fis = new FileInputStream(txtPath);
                    out.putNextEntry(new ZipEntry("AdzConfig_" + ranStr + ".json"));
    
                    //写入压缩文件
                    int len;
                    byte[] buffer = new byte[1024];
                    while ((len = fis.read(buffer)) > 0) {
                        out.write(buffer, 0, len);
                    }
                    out.closeEntry();
                    fis.close();
                }
                out.close();
                out.flush();
                
                //删除临时文件
                for (String tempFile : tempFiles) {
    				File file = new File(tempFile);
    				file.delete();
    			}
                
                return zipPath;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    
    }

然后设置响应信息，以压缩包形式返回给前端下载。

//获取web项目根目录
    String rootPath = request.getSession().getServletContext().getRealPath("/");
    //创建zip文件并返回zip文件路径
    String zipPath = new FileToZipUtil().createZipAndReturnPath(txtName ,jsonString, rootPath);
    try {
    	String fileName = URLEncoder.encode(zipName,"UTF-8") + ".zip";
    	response.reset();
    	response.setCharacterEncoding("utf-8");
    	response.setContentType("application/zip;charset=utf-8");
    	response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
    
    	//开始下载
    	BufferedInputStream is = new BufferedInputStream(new FileInputStream(new File(zipPath)));
    	BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
    
    	byte[] buff = new byte[1024];
    	int len = 0;
    	while ((len = is.read(buff, 0, buff.length)) != -1) {
    		out.write(buff, 0, len);
    	}
    	out.close();
    	out.flush();
    	is.close();
    	//删除临时压缩包
    	File file = new File(zipPath);
    	file.delete();
    } catch (Exception e) {
    	e.printStackTrace();
    }