import java.io.*;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by fang on 16/8/6.
 */
public class Connect {

    public static int skipBefore = 5;
    public static int skipend = 4;

    // 基线，达到这个行数则写到文件
    public static int baseLine = 900000;

    public static String baseDir = "";
    public static String dataDir = "";
    public static String outputDir = "";
    public static int outputIndex = 1;


    public static void main(String[] args) {
        List<String> table = new ArrayList<>();

        baseDir = args[0];
        skipBefore = Integer.parseInt(args[1]);
        skipend = Integer.parseInt(args[2]);
        baseLine = Integer.parseInt(args[3]);

        dataDir = baseDir + "/data";
        outputDir = baseDir + "/output";

        System.out.println("所有csv文件请放在data文件夹下");
        System.out.println("合并时，跳过前"+skipBefore+"行");
        System.out.println("合并时，跳过后"+skipend+"行");
        System.out.println("合并后的csv文件，放在output文件夹下");
        System.out.println("\n\n");

        System.out.println("正在合并文件，请等待...");

        File file=new File(dataDir);
        File[] files = file.listFiles();
        for(int i=0;i<files.length;i++) {
            // 大于90w行直接写
            if(table.size() > baseLine){
                write(table);
                table = new ArrayList<>();
            }

            List<String> lines = getLines(files[i].getAbsolutePath());
            table.addAll(lines.subList(skipBefore, lines.size() - skipend));
        }

        write(table);
        System.out.println("合并文件...成功");
    }

    public static List<String> getLines(String fileName) {
        List<String> table = new ArrayList<>();

        File file = new File(fileName);
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new FileReader(file));
            String line = null;
            // 一次读入一行，直到读入null为文件结束
            while ((line = reader.readLine()) != null) {
                table.add(line);
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e1) {
                }
            }
        }
        return table;
    }

    public static void write(List<String> table){
        try {
            FileWriter fw = new FileWriter(outputDir+"/final"+outputIndex+".csv");

            for (int i = 0; i < table.size(); i++) {
                fw.write(table.get(i)+"\n");
            }

            fw.close();

            System.out.println(outputDir+"/final"+outputIndex+".csv  合并完成");
            outputIndex ++;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

windows下运行bat脚本

• 参数1：合并程序的根目录
• 参数2：对每个文件跳过开头5行
• 参数3：对每个文件跳过结尾4行
• 参数4：超过90w条数据，开始合并一次

java -Xmx512m -cp excel-1.0.jar Connect "C://excel_link" 5 4 900000
pause