自定义异常

/**
 * 自定义IO异常
 * @author Administrator
 *
 */
public class FileWriterIoException extends RuntimeException {

	private static final long serialVersionUID = -3105736191743754320L;
	
	public FileWriterIoException(String msg){
		super(msg);
	}
}

调用的时候直接 throw new FileWriterIoException("创建流错误！");