编译Java代码时未报告的exceptionjava.io.IOException

我遇到此代码的问题：

public class gravityv1 { public static double[] calculategravity(double[] mass, int[] diameter) { double[] gravity = new double[mass.length]; for (int n = 0; n < mass.length; n++) { gravity[n] = (6.67E-11 * mass[n]) / Math.pow((diameter[n] / 2), 2); } return gravity; } public static void print(double[] gravity, double[] mass, int[] diameter, String[] planet) { System.out.println(" Planetary Data"); System.out.println("Planet Diameter(km) Mass(kg) g(m/s^2)"); System.out.println("---------------------------------------------------------------------"); for (int n = 0; n < planet.length; n++) System.out.printf("%-7s%15d%20.3f%14.2f", planet[n], diameter[n], mass[n], gravity[n]); } public static void printFile(double[] gravity) throws IOException { PrintWriter outFile = new PrintWriter(new File("gravity.txt")); for (double gravita: gravity) { outFile.println(gravita); } outFile.close(); } public static void main(String[] args) { String[] planet = { "Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune" }; double[] mass = {.330E24, 4.87E24, 5.97E24, 0.642E24, 1898E24, 568E24, 86.8E24, 102E24 }; int[] diameter = { 4879, 12104, 12756, 6792, 142984, 120536, 51118, 49528 }; double[] gravity = calculategravity(mass, diameter); print(gravity, mass, diameter, planet); printFile(gravity); } } 

每当我尝试编译此代码时，在“ printFile(gravity) ”处出现错误，该错误位于底部。 错误消息是：

未报告的exceptionjava.io.IOException; 必须被抓住或宣布被抛出。

我不知道该怎么办。

Answer 1

您需要在main方法中围绕抛出IOException所有方法使用try-catch块：

 try { printFile(gravity); } catch (IOException ex) { // handle exception here } 

包括签名后throws IOException所有方法。

Answer 2

将主方法声明更改为：

public static void main(String[] args) throws IOException

在Java中，每个方法A调用另一个方法B，必须声明所有exception
哪个B可以抛出（除非它们是RuntimeException后代或除非A.
正在try-catch块中显式捕获和处理它们。

在你的情况下A是main ，B是printFile 。