java 语言CSV格式文件的生成

客官°小女子只卖身不卖艺 2022-10-27 01:35 312阅读 0赞

今天和大家分析java 语言CSV格式文件的生成：

此文件格式类似excel，但是比excel生成简单、易用，

1、首先引入jar：

<dependency>
          <groupId>org.apache.commons</groupId>
          <artifactId>commons-csv</artifactId>
          <version>1.6</version>
        </dependency>

2、工具类代码：

// 写CSV格式文件，data参数可以是字符串等格式，此处处理遍历换行问题
        public static int writeCSVFile(String filePathName,List<JSONObject> data) {
            log.info("开始写文件：{}",filePathName);
            if (CollectionUtils.isEmpty(data)) {
                log.info("文件内容为空");
                return 0;
            }
            CSVPrinter csvPrinter = null;
            File file = new File(filePathName);
            // 获取json key作为csv表头
            Object[] headers = data.get(0).keySet().toArray();
            try {
                CSVFormat csvFormat = CSVFormat.DEFAULT.withRecordSeparator("\r\n")
                        .withQuoteMode(QuoteMode.ALL).withNullString("");//
                OutputStreamWriter mlFileWriter = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_8.toString());
                csvPrinter = new CSVPrinter(mlFileWriter, csvFormat);
                csvPrinter.printRecord(headers);
                for(JSONObject jsondata : data){
                    csvPrinter.printRecord(jsondata.values());
                }
            } catch (IOException e) {
                log.error("异常", e);
                throw new RuntimeException("文件创建失败", e);
            }finally {
                try {
                    csvPrinter.flush();
                    csvPrinter.close();
                }catch (Exception e) {
                    log.error("关闭文件流错误", e);
                }
            }
            return 0;
        }

3、main方法测试：

public static void main(String[] args) {
            writeCSVFile();
        }
    
        private static String writeCSVFile(){
            String NEW_LINE_SEPARATOR = "\r\n";
         //   List<JSONObject> data = new ArrayList<>();
            CabkeInfi cabkeInf = new CabkeInfi();
            cabkeInf.setAttribute("nan");
            cabkeInf.setName("si");
            CabkeInfi cabkeInfi = new CabkeInfi();
            cabkeInfi.setAttribute("nandao");
            cabkeInfi.setName("lisi");
            List<CabkeInfi> list = new ArrayList<>();
            list.add(cabkeInf);
            list.add(cabkeInfi);
          //  JSON.t
    
         //   JSONArray json = JSONArray.fromObject(list);
         //   String str = json.toString();//把json转换为String
            String s = JSON.toJSONString(list, SerializerFeature.WriteMapNullValue);
            String sQuoteFieldNames = JSON.toJSONString(list, SerializerFeature.QuoteFieldNames);
            String UseSingleQuotes = JSON.toJSONString(list, SerializerFeature.UseSingleQuotes);
            log.info("字符串打印：{}",s);
            log.info("字符串打印：{}",sQuoteFieldNames);
            log.info("字符串打印：{}",UseSingleQuotes);
            List<JSONObject> data = JSONObject.parseArray(s,JSONObject.class);
    
           JSONObject jsonObject = (JSONObject) JSONObject.toJSON(cabkeInf);
            JSONObject jsonObjec = (JSONObject) JSONObject.toJSON(cabkeInfi);
          //  data.add(jsonObjec);
        //    data.add(jsonObject);
    
            //data =new ArrayList<JSONObject> (JSONObject.t);
            if (CollectionUtils.isEmpty(data)) {
                return null;
            }
            CSVPrinter csvPrinter = null;
           // String filePathName =null;
             String filePathName = "E:\\日常工作\\项目\\"+"RDnandaoCSV";//测试地址
            filePathName = filePathName + ".csv";
            File file = new File(filePathName);
            // 获取json key作为csv表头
            Object[] headers = data.get(0).keySet().toArray();
            try {
                CSVFormat csvFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR)
                        .withQuoteMode(QuoteMode.ALL).withNullString("");
                OutputStreamWriter mlFileWriter = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_8.toString());
                csvPrinter = new CSVPrinter(mlFileWriter, csvFormat);
                csvPrinter.printRecord(headers);
                for(JSONObject jsondata : data){
                    csvPrinter.printRecord(jsondata.values());
                }
            } catch (IOException e) {
                log.error("异常", e);
                throw new RuntimeException("文件创建失败", e);
            }finally {
                try {
                    csvPrinter.flush();
                    csvPrinter.close();
                }catch (Exception e) {
                    log.error("关闭文件流错误", e);
                }
            }
            return filePathName;
        }

4、执行完生成这样的文件，打开后如下：

RDnandaoCSV.csv  文件打开

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L25hbmRhbzE1OA_size_16_color_FFFFFF_t_70][]

到此CSV生成分析完成，下篇分享文件一般文件生成 问题，敬请期待！

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L25hbmRhbzE1OA_size_16_color_FFFFFF_t_70]: /images/20221024/15384a276ab1443abe7cd9b0129904e9.png