java实现CSV文件读写

约定不等于承诺〃 2022-05-23 05:06 221阅读 0赞

问题场景,公司需求对图片表数据进行分析(大小,像素,长,宽),以CSV形式进行操作.  
1.准备操作  
Maven

<dependency>
          <groupId>net.sourceforge.javacsv</groupId>
          <artifactId>javacsv</artifactId>
          <version>2.0</version>
        </dependency>

API 说明文档：[http://javacsv.sourceforge.net/][http_javacsv.sourceforge.net]  
JavaCSV官网：[https://sourceforge.net/projects/javacsv/][https_sourceforge.net_projects_javacsv]  
[javacsv-2.1.jar点击下载][javacsv-2.1.jar]

2.代码展示

package com.dongshuo;
    
    import com.csvreader.CsvReader;
    import com.csvreader.CsvWriter;
    
    import java.io.FileNotFoundException;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.nio.charset.Charset;
    import java.util.ArrayList;
    import java.util.List;
    
    /** * @author dongshuo * @data 2018/5/31 17:51 * @Description csv 文件读写操作 */
    public class CSVUtil { 
        //static String readPath = "D:/image/p_sku_pop_relation.csv";
    
        /** * 读取每行的数据 * * @param readPath * @return */
        public static List<String> readCSV(String readPath) {
            String filePath = readPath;
            List<String> listData = new ArrayList<>();
            try {
                filePath = readPath;
                CsvReader csvReader = new CsvReader(filePath);
                // 读表头
                boolean re = csvReader.readHeaders();
                while (csvReader.readRecord()) {
                    String rawRecord = csvReader.getRawRecord();
                    listData.add(rawRecord);
                }
                return listData;
            } catch (FileNotFoundException e) {
                throw new RuntimeException("文件未找到");
            } catch (IOException e) {
                throw new RuntimeException(e.getMessage());
            }
    
        }
    
        /** * 写入文件头 * @param writePath * @param header */
        public static void writeCSV(String writePath, String[] header) {
            String filePath = writePath;
            try {
                CsvWriter csvWriter = new CsvWriter(writePath, ',', Charset.forName("UTF-8"));
                //String [] header = {"SkuId","SsuId","图片地址","大小(bit)","高度","宽度"};
                csvWriter.writeRecord(header);
                csvWriter.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
    
        }
    
        /** * 利用输入输出流持续写 * @param fileName * @param content */
        public static void writeContent(String fileName, String content) {
            FileWriter writer = null;
            try {
                // 打开一个写文件器，构造函数中的第二个参数true表示以追加形式写文件
                writer = new FileWriter(fileName, true);
                writer.write(content + "\r\n");
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (writer != null) {
                        writer.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

我翻阅了文档javacsv不支持追加写,所以采用的输出流完成追加写  
为了提高速度,采用多线程,并发执行

[http_javacsv.sourceforge.net]: http://javacsv.sourceforge.net/
[https_sourceforge.net_projects_javacsv]: https://sourceforge.net/projects/javacsv/
[javacsv-2.1.jar]: http://gd-rus-public.cn-hangzhou.oss-pub.aliyun-inc.com/attachment/201612/02/20161202190434/javacsv-2.1.jar