Java导出CSV文件

缺乏、安全感 2021-12-21 07:17 355阅读 0赞

通过页面按钮点击导出csv:

步骤:

1.创建临时文件

2.下载到本地

3.删除临时文件

传入数据直接调用即可:
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.net.URLEncoder;
    import java.util.List;
    
    import javax.servlet.http.HttpServletResponse;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    /**
     * csv文件操作
     * @author kangzhuang
     * @Date 20190627
     */
    public class CsvUtils {
        /**
         * 日志
         */
        private static final Logger logger = LoggerFactory.getLogger(CsvUtils.class);
        /**
         * 生成为CVS文件
         * @author kangzhuang
         * @param exportData 源数据List
         * @param titles        csv文件的列表头titles
         * @param outPutPath 文件路径
         * @param fileName   文件名称
         * @return
         */
        @SuppressWarnings("rawtypes")
        public static File createCsvFile(List<Object[]> exportData, String[] titles,String outPutPath,String fileName) {
            File csvFile = null;
            BufferedWriter csvFileOutputStream = null;
            try {
                File file = new File(outPutPath);
                if (!file.exists()) {
                    file.mkdir();
                }
                //定义文件名格式并创建
                csvFile = new File(outPutPath+File.separator+fileName);
                // UTF-8使正确读取分隔符","
                csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(
                        csvFile), "UTF-8"), 1024);
                // 写入文件头部
                for(String title : titles){
                    csvFileOutputStream.write(title);
                    csvFileOutputStream.write(",");
                }
                //换行
                csvFileOutputStream.newLine();
                if(exportData!=null && !exportData.isEmpty()){
                    for (int i = 0; i < exportData.size(); i++) {
                        Object[] obj = exportData.get(i);
                        if (obj!=null){
                            for (int j = 0; j < obj.length; j++) {
                                csvFileOutputStream.write(obj[j].toString());
                                csvFileOutputStream.write(",");
                            }
                            if (i< exportData.size()){
                                //换行
                                csvFileOutputStream.newLine();
                            }
                        }
    
                    }
                }
                csvFileOutputStream.flush();
            } catch (Exception e) {
                logger.error("CsvUtils createCSVFile Exception:{}",e);
            } finally {
                try {
                    if (csvFileOutputStream!=null){
                        csvFileOutputStream.close();
                    }
                } catch (IOException e) {
                    logger.error("CsvUtils createCSVFile IOException:{}",e);
                }
            }
            return csvFile;
        }
    
        /**
         * 下载文件
         * @author kangzhuang
         * @param response
         * @param csvFilePath 文件路径
         * @param fileName    文件名称
         * @throws IOException
         */
        public static void exportFile(HttpServletResponse response, String csvFilePath, String fileName) {
            logger.info("exportFile csvFilePath:{}",csvFilePath);
            InputStream in = null;
            OutputStream out = null;
            try {
                response.setContentType("application/csv;charset=UTF-8");
                response.setHeader("Content-Disposition",
                        "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));
                in = new FileInputStream(csvFilePath);
                int len = 0;
                byte[] buffer = new byte[1024];
                response.setCharacterEncoding("UTF-8");
                out=response.getOutputStream();
                while ((len = in.read(buffer)) > 0) {
                    out.write(new byte[]{(byte) 0xEF, (byte) 0xBB, (byte) 0xBF});
                    out.write(buffer, 0, len);
                }
                out.flush();
            } catch (FileNotFoundException e) {
                logger.error("CsvUtils exportFile FileNotFoundException:{}",e);
            } catch (IOException e) {
                logger.error("CsvUtils exportFile IOException :{}",e);
            } finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                    if (out != null) {
                        out.close();
                    }
                } catch (Exception e) {
                    logger.error("CsvUtils exportFile Exception:{}",e);
                    throw new RuntimeException(e);
                }
    
            }
    
        }
        /**
         * 删除单个文件
         * @author kangzhuang
         * @param filePath
         *     文件目录路径
         * @param fileName
         *     文件名称
         */
        public static void deleteFile(String filePath, String fileName) {
            logger.error("CsvUtils deleteFile  fileName:{}",fileName);
            File file = new File(filePath);
            if (file.exists()) {
                File[] files = file.listFiles();
                for (int i = 0; i < files.length; i++) {
                    if (files[i].isFile()&&fileName!=null&&fileName.equals(files[i].getName())) {
                        files[i].delete();
                        return;
                    }
                }
            }
        }
    }