https://www.iamshuaidi.com/31455.html

https://blog.csdn.net/sinat_32856935/article/details/81449973

package com.dairui.chars;
 
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.PublicKey;
 
public class FileCopyFile {
	public static void main(String[] args) throws IOException {
		FileManage fileManage1 = new FileManage("/Users/dary/Desktop/index1.php", new char[] { '\\n' });
		FileManage fileManage2 = new FileManage("/Users/dary/Desktop/index2.php", new char[] { '\\n', ' ' });
		FileWriter cFile = new FileWriter("/Users/dary/Desktop/index3.php");
		String aWord = null;
		String bWord = null;
		while ((aWord = fileManage1.nextWord()) != null) {
			cFile.write(aWord + "\\n");
			if ((bWord = fileManage2.nextWord()) != null) {
				cFile.write(bWord + "\\n");
			}
		}
		while ((bWord = fileManage2.nextWord()) != null) {
			cFile.write(bWord + "\\n");
		}
		cFile.close();
 
	}
 
}
 
class FileManage {
 
	String[] words = null;
	int pox = 0;
 
	public FileManage(String filename, char[] seperators) throws IOException {
		File file = new File(filename);
		try {
			FileReader fileReader = new FileReader(file);
			char[] ch = new char[(int) file.length()];
			int len = fileReader.read(ch);
			String reString = new String(ch, 0, len);
			String regx = null;
 
			if (seperators.length > 1) {
				regx = "" + seperators[0] + "|" + seperators[1];
			} else {
				regx = "" + seperators[0];
			}
 
			words = reString.split(regx);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
 
	}
 
	public String nextWord() {
		if (pox == words.length) {
			return null;
		}
		return words[pox++];
	}
}