手动抛出异常和自定义异常

如何自定义异常类

1. 继承现有的异常结构：RuntimeException（运行时异常）、Exception

2. 提供全局常量：serialVersionUID

3. 提供多个重载构造方法

   package October_13;
   
   public class test2 extends RuntimeException {
   	static final long serialVersionUID = -7034897190745766939L;
   	public test2() {
   
   	}
   
   	public test2(String msg) {
       	super(msg);
   	}
   }
   

如何手动抛出异常

1. throw new 异常类名

package October_13;

public class test {
    public static void main(String[] args) {
        t t = new t();
        t.re(-1010);
        System.out.println(t);
    }
}

class t {
    private int id;
    public void re(int id) {
        if (id > 0) {
            this.id = id;
        } else {
            throw new test2("调用test2自定义异常");
        }
    }

    @Override
    public String toString() {
        return "t{" +
                "id=" + id +
                '}';
    }
}