Java开发

问题： 如何抛出一个系统异常并且捕获它

代码如下：

public class ThrowDemo {
    static void demoproc() {
        try {
            throw new NullPointerException("demo");
        } catch (NullPointerException e) {
            System.out.println("Caught inside demoproc.");
            throw e; // rethrow the exception
        }
    }

    public static void main(String args[]) {
        try {
            demoproc();
        } catch (NullPointerException e) {
            System.out.println("Recaught: " + e);
        }
    }
}

运行结果：

Caught inside demoproc.
Recaught: java.lang.NullPointerException: demo