问题描述
我正在阅读下面的文本文件内容，并使用下面的代码将其写入控制台。
file content
james;mask;1980
Mos;josh;1960
我如何在新列中添加新行来计算从出生年份开始的年份
public class Readfile {
public static void main(String[] args) {
// Create file
File file = new File("/Users/James/documents/Huber.txt");
try {
// Create a buffered reader
// to read each line from a file.
BufferedReader in = new BufferedReader(new FileReader(file));
String ch;
// Read each line from the file and echo it to the screen.
while ((ch = in.readLine()) != null) {
System.out.println(ch);
}
// Close the buffered reader
in.close();
} catch (FileNotFoundException e1) {
// If this file does not exist
System.err.println("File not found: " + file);
} catch (IOException e2) {
// Catch any other IO exceptions.
e2.printstacktrace();
}
}
}
解决方法
假定出生日期不超过当前日期。
StringBuffer inputBuffer = new StringBuffer();
while ((ch = in.readLine()) != null) {
System.out.println(ch);
if(ch.split(";").length < 3){ //data unavailable
inputBuffer.append(ch).append("\n");
continue;
}
int year;
try { //dob not specified
year = Integer.parseInt(ch.split(";")[2]);
} catch(NumberFormatException e){
inputBuffer.append(ch).append(";N/A").append("\n");
continue;
}
int age = LocalDate.now().getYear() - year;
inputBuffer.append(ch).append(";").append(age).append("\n");
}
// Close the buffered reader
in.close();
FileOutputStream fileOut = new FileOutputStream(file.getAbsolutePath());
fileOut.write(inputBuffer.toString().getBytes());
fileOut.close();