java编程作业

来源:百度知道 编辑:UC知道 时间:2024/05/23 13:53:39
老师布置的作业怎么做:java利用文件输入输出流,从文件中读入数据——运算——结果输出(输入、输出、创建变量)

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class FileInputOutput {
public static void main(String[] args) {
try {
File f = new File("text.txt");
if (!f.exists())
f.createNewFile();
String str[] = { "1", "2", "3", "4", "5", "6", "7", "-600" };
FileWriter fw = new FileWriter(f);
for (int i = 0; i < str.length; i++) {
fw.append(str[i]);
fw.append("\n");
}
fw.flush();
FileReader fr = new FileReader(f);
BufferedReader br = new BufferedReader(fr);
int sum = 0;
while (true) {
String num = br.readLine();
if (num == null)
break;
try {
sum += Integer.parseInt(num);
} catch (Number