Java文本文件与集合之间数据的拷贝

直接上代码

package demo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;

//文本文件与集合之间数据的拷贝
public class IODemo2 {

	public static void main(String[] args) throws IOException {
		// 创建list集合
		ArrayList<String> arrayList = new ArrayList<>();
		// 向集合添加数据
		arrayList.add("data1");
		arrayList.add("data2");
		arrayList.add("data3");

		// if (!arrayList.isEmpty()) {
		// list2txt(arrayList, "list2txt.txt");
		// }

		if (!arrayList.isEmpty()) {
			arrayList.clear();
			txt2list(arrayList, "list2txt.txt");
		}

	}

	// 把集合的数据，拷贝到文本文件中
	public static void list2txt(ArrayList<String> arrayList, String fileName)
			throws IOException {
		// 创建输出缓冲流
		BufferedWriter writer = new BufferedWriter(new FileWriter(fileName));

		// 循环遍历list集合
		for (int i = 0; i < arrayList.size(); i++) {
			String data = arrayList.get(i);
			writer.write(data);
			writer.newLine();
			writer.flush();
		}

		writer.close();
		System.out.println("集合数据拷贝到文件完成！");
	}

	// 把文本文件的数据，拷贝到集合中
	public static void txt2list(ArrayList<String> arrayList, String fileName)
			throws IOException {
		// 创建输入缓冲流
		BufferedReader reader = new BufferedReader(new FileReader(fileName));
		// 读取数据，没读取一行，把改行数据作为元素存储到集合中
		String line;

		while ((line = reader.readLine()) != null) {
			arrayList.add(line);
		}
		reader.close();
		System.out.println("文本文件拷贝到集合完成！集合输出为：");
		for (int i = 0; i < arrayList.size(); i++) {
			System.out.println(arrayList.get(i));
		}
	}
}