import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.nio.charset.Charset;

import java.util.Random;

import org.springframework.util.StringUtils;

import com.csvreader.CsvReader;

import com.csvreader.CsvWriter;

/**

 * 获取和写入csv文件内容

 * <p>

 * @author DennyZhao

 * @since 1.0.0

 */

public class CSVUtils {

    /**

     * 默认分隔符

     */

    private static final char DEFAULT_SEPERATE_CHAR = ',';

    /**

     * 默认charset

     */

    private static final Charset DEFAULT_CHARSET = Charset.defaultCharset();

    /**

     * 写数据

     * @param targetFilePath

     * @param fileName

     * @param seperateChar

     * @param charsetName

     * @throws IOException

     */

    public static void writeFile(String targetFilePath, String fileName, char seperateChar, String charsetName) throws IOException {

     // 判断文件是否存在

        File file = new File(targetFilePath);

        if(!file.exists()) {

            file.mkdirs();

        }

        // 判断是否有seperateChar

        if(seperateChar == 0) {

            seperateChar = DEFAULT_SEPERATE_CHAR;

        }

        // 判断是否有charset

        Charset charset = DEFAULT_CHARSET;

        if(!StringUtils.isEmpty(charsetName)) {

            charset = Charset.forName(charsetName);

        }

        String filePath = targetFilePath + File.separatorChar + fileName;

        // 获取csv文件及其数据

        CsvWriter csvWriter = new CsvWriter(filePath, seperateChar, charset);

        csvWriter.setForceQualifier(true);          //这个决定了一般文件打开是不是有“”存在

        String[] strHeader = {"userId","userName", "userAge"};

        csvWriter.writeRecord(strHeader);

        for(int i=0; i < 50; i++) {

            String[] strArray = {i + "","张三" + i, (new Random()).nextInt(100) + ""};

            csvWriter.writeRecord(strArray);

        }

        csvWriter.endRecord();

        csvWriter.close();

    }

    /**

     * 读取csv文件中的数据

     * @param originFile 要读入的文件

     * @param seperateChar 分割符

     * @param charsetName 编码格式

     * @throws IOException

     */

    public static void readFile(String originFile, char seperateChar, String charsetName) throws IOException {

        // 判断文件是否存在

        File file = new File(originFile);

        if(!file.exists()) {

            System.out.println("file is not exist...");

            return;

        }

        // 判断是否有seperateChar

        if(seperateChar == 0) {

            seperateChar = DEFAULT_SEPERATE_CHAR;

        }

        // 判断是否有charset

        Charset charset = DEFAULT_CHARSET;

        if(!StringUtils.isEmpty(charsetName)) {

            charset = Charset.forName(charsetName);

        }

        // 获取csv文件及其数据

        CsvReader csvReader = new CsvReader(originFile, seperateChar, charset);

        while(csvReader.readRecord()) {

            //读取完毕

            if(csvReader.getColumnCount() == 0) {

                break;

            }

            long index = csvReader.getCurrentRecord();   //当前记录index

            System.out.println("index:  " + index);

            if(index == 0) {

                String[] headerArray = csvReader.getValues();

            }

            String userName = csvReader.get(1);          //读取单条数据

            String[] valArray = csvReader.getValues();   //读取数据变为数组

            String recorder = csvReader.getRawRecord();  //直接读取一行数据

        }

        csvReader.close();

    }

    public static void main(String[] args) throws IOException {

        // 读数据

        //String originFile = "C:\\Users\\zhaoq\\Desktop\\reader.csv";

        //readFile(originFile, ',', "gb2312");

        // 写数据

        String targetFilePath = "C:\\Users\\zhaoq\\Desktop";

        String fileName = "writer.csv";

        writeFile(targetFilePath, fileName, ',', "gb2312");

    }

}