JAVA —— 文件输入输出

import java.io.*;

public class FileIO {

	public static void main(String[] args) {

		//1.相对路径
		File testFile1=new File("test1.txt");
		//2.绝对路径
		//错误：
		//File testFile2=new File("E:\Java\test2.txt");
		File testFile2=new File("E:/Java/test2.txt");
		String s1;
		StringBuffer sb1=new StringBuffer();
		try {
			BufferedReader reader =
			new BufferedReader(new FileReader(testFile1));
			s1 = reader.readLine();
			while(s1!=null){
				sb1.append(s1+"\n");
				s1=reader.readLine();
			}
			System.out.println(sb1);
			reader.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

		try {
			BufferedWriter writer =
			new BufferedWriter(new FileWriter(testFile2));
			writer.write(sb1.toString());
			//错误
			//忘记清空缓冲，关闭流
			writer.flush();
			writer.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

}