oracle pl/sql异常处理

DECLARE
colse_result varchar2(100);
BEGIN
utl_http.set_wallet ('密钥地址', '密码');
select utl_http.request('请求url') INTO colse_result from dual;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('An error has occurred');
DBMS_OUTPUT.PUT_LINE(colse_result);
END;