java中从1970-1-1到当前时间之间的毫秒数转换为oracle date

select sessiontimezone,dbtimezone,sysdate,current_date from dual;

CREATE OR REPLACE PACKAGE cux_time_utils_pkg IS FUNCTION unix_timestamp_to_utc_date(in_unix_timestamp IN NUMBER) RETURN DATE DETERMINISTIC; FUNCTION unix_timestamp_to_session_date(in_unix_timestamp IN NUMBER) RETURN DATE DETERMINISTIC; FUNCTION date_to_unix_timesecond(in_date IN DATE) RETURN NUMBER DETERMINISTIC; FUNCTION date_to_unix_times_millis(in_date IN DATE) RETURN NUMBER DETERMINISTIC; FUNCTION java_currenttimemillis RETURN NUMBER; FUNCTION current_unix_times_millis RETURN NUMBER DETERMINISTIC;

--时间格式转格林威治时间
      FUNCTION date_to_gmt_time(p_date IN DATE) RETURN VARCHAR2;

END; 

CREATE OR REPLACE PACKAGE BODY cux_time_utils_pkg IS --return utc0 date
--返回0时区时间
FUNCTION unix_timestamp_to_utc_date(in_unix_timestamp IN NUMBER) RETURN DATE DETERMINISTIC IS
v_date DATE;
BEGIN
v_date := to_date('1970-01-01',
'yyyy-mm-dd') + in_unix_timestamp / 1000 / 60 / 60 / 24;
RETURN v_date;
END; --return sessiontimezone date
--返回当前回话时区时间
--select sessiontimezone,dbtimezone,sysdate,current_date from dual;
FUNCTION unix_timestamp_to_session_date(in_unix_timestamp IN NUMBER) RETURN DATE DETERMINISTIC IS
v_date DATE;
BEGIN
v_date := to_date('1970-01-01',
'yyyy-mm-dd') + in_unix_timestamp / 1000 / 60 / 60 / 24 +
to_number(substr(tz_offset(sessiontimezone),
1,
3)) / 24;
RETURN v_date;
END; --返回1970-01-01 00:00:00到in_date之间的秒数
FUNCTION date_to_unix_timesecond(in_date IN DATE) RETURN NUMBER DETERMINISTIC IS
v_unix_timestamp NUMBER;
BEGIN
v_unix_timestamp := (in_date - to_date('1970-01-01',
'yyyy-mm-dd')) * 60 * 60 * 24;
RETURN v_unix_timestamp;
END; --返回1970-01-01 00:00:00到in_date之间的毫秒数
--此方法不够精确，因为in_date精度为秒，所以返回值的精度为千毫秒
--可调整入参结构为timestamp,再进行优化
FUNCTION date_to_unix_times_millis(in_date IN DATE) RETURN NUMBER DETERMINISTIC IS
v_unix_timestamp NUMBER;
BEGIN
v_unix_timestamp := (in_date - to_date('1970-01-01',
'yyyy-mm-dd')) * 1000 * 60 * 60 * 24;
RETURN v_unix_timestamp;
END; --返回java的当前毫秒数
FUNCTION java_currenttimemillis RETURN NUMBER AS
LANGUAGE JAVA NAME 'java.lang.System.currentTimeMillis() return java.lang.Integer'; --返回当前时间的毫秒数
FUNCTION current_unix_times_millis RETURN NUMBER DETERMINISTIC IS
v_unix_timestamp NUMBER;
BEGIN
v_unix_timestamp := extract(DAY FROM(systimestamp - to_timestamp('1970-01-01',
'YYYY-MM-DD'))) * 1000 * 60 * 60 * 24 +
to_number(to_char(sys_extract_utc(systimestamp),
'SSSSSFF3'));
RETURN v_unix_timestamp;
END;

--时间格式转格林威治时间
FUNCTION date_to_gmt_time(p_date IN DATE) RETURN VARCHAR2 IS
l_return_str VARCHAR2(50);
BEGIN
IF p_date IS NOT NULL THEN
SELECT to_char(p_date, 'YYYY-MM-DD') || 'T' ||
 to_char(p_date, 'HH24:MI:SS') || '.000+08:00'
INTO l_return_str
FROM dual;
ELSE
l_return_str := NULL;
END IF;

RETURN l_return_str;

END;

END;