Question

我需要使用openCSV实用程序使用新值更新行。比方说，我在CSV文件下面，我需要分别将包含TestdminUsername1和TestdminUsername2的行更新为TestdminUsername1,Fail,Errors Found和TestdminUsername2,Fail,Errors Found。

TestdminUsername1,Pass,No Error
TestAdminUsername2,Pass,No Error
TestAdminUsername3,Pass,No Error
TestAdminUsername4,Pass,No Error
TestAdminUsername5,Pass,No Error
TestAdminUsername6,Pass,No Error
TestAdminUsername7,Pass,No Error
TestAdminUsername8,Pass,No Error
TestAdminUsername9,Pass,No Error
TestAdminUsername10,Pass,No Error

以下是我正在使用的代码：

import java.io.FileReader;
import java.io.FileWriter;
import java.util.Arrays;

import com.opencsv.CSVReader;
import com.opencsv.CSVWriter;

public class AppendToCSVExample
{
    @SuppressWarnings("resource")
    public static void main(String[] args) throws Exception
   {
      String csv = "D:\\data2.csv";
      CSVWriter writer = new CSVWriter(new FileWriter(csv, true));
      String [] record1 = "TestdminUsername1,Pass,No Error".split(",");
      String [] record2 = "TestAdminUsername2,Pass,No Error".split(",");
      String [] record3 = "TestAdminUsername3,Pass,No Error".split(",");
      String [] record4 = "TestAdminUsername4,Pass,No Error".split(",");
      String [] record5 = "TestAdminUsername5,Pass,No Error".split(",");
      String [] record6 = "TestAdminUsername6,Pass,No Error".split(",");
      String [] record7 = "TestAdminUsername7,Pass,No Error".split(",");
      String [] record8 = "TestAdminUsername8,Pass,No Error".split(",");
      String [] record9 = "TestAdminUsername9,Pass,No Error".split(",");
      String [] record10 = "TestAdminUsername10,Pass,No Error".split(",");

      writer.writeNext(record1);
      writer.writeNext(record2);
      writer.writeNext(record3);
      writer.writeNext(record4);
      writer.writeNext(record5);
      writer.writeNext(record6);
      writer.writeNext(record7);
      writer.writeNext(record8);
      writer.writeNext(record9);
      writer.writeNext(record10);

      writer.close();

      CSVReader reader = new CSVReader(new FileReader("D:\\data1.csv"), ',' , '"' , 1);

      String[] nextLine;
      while ((nextLine = reader.readNext()) != null) {
          if (nextLine != null) {
         //Verifying the read data here
         System.out.println(Arrays.toString(nextLine));
         String[] parts = Arrays.toString(nextLine).split(",");
         if (parts[0].toString().contains("TestdminUsername1")) {
             String [] recordTest = "TestdminUsername1, Fail, Errors found".split(",");
              //Which method in openCSV needs to be used to update recordTest value in the File data2.csv
             ;
         }
      }
    }
  }
}

Answer 1

我个人建议你打开第二个CSVWriter到一个新文件（data3.csv），当你从data1读取时，你写入data3改变需要修改的数据。这样，如果您因任何原因失败，您仍然拥有原始文件。最后，如果您只想要一个文件，则可以删除data1并将data3.csv重命名为data1.csv。

有一个先前的问题，有人试图同时读取和写入同一个文件（Reading from a CSV file and writing to a new CSV file using openCSV in java），但如果出现错误，我会再次提出建议。

使用openCSV使用新值更新行

1 个答案: