處理NSE數據時，會提取和重組一些數據，現在一共有兩個方法，一個是 java 自帶的方法，一個就是用一個第三方的庫 CSVReader。

java 自帶的 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();
}

簡單寫法如下

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 庫讀取

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();
}

感覺浪費了好多時間編輯這個東西，不過個人感覺這些東西有一天會有用的。

個人學習資料，如有雷同，那必然是巧合