java 中处理csv文件

处理NSE数据时，会提取和重组一些数据，现在一共有两个方法，一个是 java 自带的方法，一个就是用一个第三方的库 CSVReader。

java 自带的 BufferedReader

import java.io.*;
private static void data_copy() throws IOException
{    
    BufferedReader br = new BufferedReader(new FileReader("your file"));    
    String line; 
    String targetFile = "F:\\data analysis";   
    java.io.File a = new java.io.File(targetFile);    
    File fileHandle = new File(a,"caochu.txt");
    FileOutputStream outStream = new FileOutputStream(fileHandle);
    while ((line = br.readLine()) != null)    
    {
        String dataContent = line + "\n";
        outStream.write(dataContent.getBytes());
    }    
    outStream.close();
    br.close();
}

简单写法如下

import java.io.*;
private static void data_copy() throws IOException
{
    BufferedReader br = new BufferedReader(new FileReader("file directory"));
    String line;
    Writer writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("target file directory"), StandardCharsets.UTF_8));
    while ((line = br.readLine()) != null)
    {    
        writer.write(line + "\n");
    }
    br.close();
    writer.close();
} 

使用 CSVReader 库读取

import com.opencsv.CSVReader;
public static void data_extractor() throws IOException, ParseException
{
    String[] nextLine;
    CSVReader reader = new CSVReader(new FileReader("file directory"));
    while ((nextLine = reader.readNext()) != null)
    {
        FileWriter dataWriter = new FileWriter("target file", false);
        PrintWriter dataContent = new PrintWriter(dataWriter);
        dataContent.printf("%s", nextLine[1]);
        dataContent.printf("%s", "\n");
    }
    dataContent.close();
}

感觉浪费了好多时间编辑这个东西，不过个人感觉这些东西有一天会有用的。

个人学习资料，如有雷同，那必然是巧合