我尝试创建一个文件并用 Java 将程序的输出写入其中。当我使用 WriteLong
时,文件不包含长值。请解释一下我如何创建这个文件。
我的程序是打印 500000
和 10000000
public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
System.out.println(i);
}
}
}
public static boolean isPrime(long i2) {
if (i2 <= 1) {
return false;
}
for (long i = 2; i < Math.sqrt(i2); i++) {
if (i2 % i == 0) {
return false;
}
}
return true;
}
}
最佳答案
我假设您希望程序打印人类可读的 ASCII 长值。您可以使用 PrintWriter
以及类似的东西,
PrintWriter pw = null;
try {
pw = new PrintWriter(filePath);
pw.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
pw.println(i);
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
pw.close();
}
或者,使用try-with-resources
try (PrintWriter pw = new PrintWriter(filePath)) {
pw.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
pw.println(i);
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
如果你想创建一个二进制文件,你可以使用 DataOutputStream
.
关于java - 长类型输出文件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/25453186/