有没有一种简单的方法可以在Oracle中使用JSON?我有一个经常用于调用Web服务的标准过程,JSON是我在Web开发上下文中熟悉的一种格式,但是在存储过程中使用JSON的最佳方法是什么?例如,从URI中获取CLOB响应,将其转换为JSON对象并从中获取值?
作为参考,这是我用来获取URL的过程
create or replace procedure macp_URL_GET(url_resp in out clob, v_url in varchar2) is req Utl_Http.req; resp Utl_Http.resp; NAME VARCHAR2 (255); VALUE VARCHAR2 (1023); v_msg VARCHAR2 (80); v_ans clob; -- v_url VARCHAR2 (32767) := 'http://www.macalester.edu/'; BEGIN /* request that exceptions are raised for error Status Codes */ Utl_Http.set_response_error_check (ENABLE => TRUE ); /* allow testing for exceptions like Utl_Http.Http_Server_Error */ Utl_Http.set_detailed_excp_support (ENABLE => TRUE ); /* Utl_Http.set_proxy ( proxy => 'www-proxy.us.oracle.com', no_proxy_domains => 'us.oracle.com' ); */ req := Utl_Http.begin_request (url => v_url, method => 'GET'); /* Alternatively use method => 'POST' and Utl_Http.Write_Text to build an arbitrarily long message */ /* Utl_Http.set_authentication ( r => req, username => 'SomeUser', PASSWORD => 'SomePassword', scheme => 'Basic', for_proxy => FALSE --this info is for the target Web server ); */ Utl_Http.set_header (r => req, NAME => 'User-Agent', VALUE => 'Mozilla/4.0'); resp := Utl_Http.get_response (r => req); /* DBMS_OUTPUT.put_line ('Status code: ' || resp.status_code); DBMS_OUTPUT.put_line ('Reason phrase: ' || resp.reason_phrase); FOR i IN 1 .. Utl_Http.get_header_count (r => resp) LOOP Utl_Http.get_header (r => resp, n => i, NAME => NAME, VALUE => VALUE); DBMS_OUTPUT.put_line (NAME || ': ' || VALUE); END LOOP; */ --test BEGIN LOOP Utl_Http.read_text (r => resp, DATA => v_msg); --DBMS_OUTPUT.put_line (v_msg); v_ans := v_ans || v_msg; url_resp := url_resp || v_msg; END LOOP; EXCEPTION WHEN Utl_Http.end_of_body THEN NULL; END; --test Utl_Http.end_response (r => resp); --url_resp := v_ans; EXCEPTION /* The exception handling illustrates the use of "pragma-ed" exceptions like Utl_Http.Http_Client_Error. In a realistic example, the program would use these when it coded explicit recovery actions. Request_Failed is raised for all exceptions after calling Utl_Http.Set_Detailed_Excp_Support ( ENABLE=>FALSE ) And it is NEVER raised after calling with ENABLE=>TRUE */ WHEN Utl_Http.request_failed THEN DBMS_OUTPUT.put_line ( 'Request_Failed: ' || Utl_Http.get_detailed_sqlerrm ); url_resp :='Request_Failed: ' || Utl_Http.get_detailed_sqlerrm; /* raised by URL http://xxx.oracle.com/ */ WHEN Utl_Http.http_server_error THEN DBMS_OUTPUT.put_line ( 'Http_Server_Error: ' || Utl_Http.get_detailed_sqlerrm ); url_resp := 'Http_Server_Error: ' || Utl_Http.get_detailed_sqlerrm; /* raised by URL http://otn.oracle.com/xxx */ WHEN Utl_Http.http_client_error THEN DBMS_OUTPUT.put_line ( 'Http_Client_Error: ' || Utl_Http.get_detailed_sqlerrm ); url_resp := 'Http_Client_Error: ' || Utl_Http.get_detailed_sqlerrm; /* code for all the other defined exceptions you can recover from */ WHEN OTHERS THEN DBMS_OUTPUT.put_line (SQLERRM); url_resp := SQLERRM; END;
然后测试
begin macp_url_get(url_resp => :url_resp, 'http://maps.googleapis.com/maps/api/geocode/json?address=55105&sensor=false'); end;
(我知道googleapi将允许xml响应,但我经常使用其他一些默认为JSON的Web API)
我已经开始使用该库,并且看起来很有希望:https : //github.com/pljson/pljson
易于安装,示例很好。
要在示例中使用该库,请将这些变量添加到过程中。
mapData json; results json_list; status json_value; firstResult json; geometry json;
....
然后,您可以将响应作为json对象操作。
-- convert the result from the get to a json object, and show some results. mapData := json(v_ans); -- Show the status of the request status := mapData.get('status'); dbms_output.put_line('Status = ' || status.get_string()); IF (status.get_string() = 'OK') THEN results := json_list(mapData.get('results')); -- Grab the first item in the list resultObject := json(results.head); -- Show the human readable address dbms_output.put_line('Address = ' || resultObject.get('formatted_address').to_char() ); -- Show the json location data dbms_output.put_line('Location = ' || resultObject.get('geometry').to_char() ); END IF;
运行以下代码会将其输出到dbms输出:
Status = OK Address = "St Paul, MN 55105, USA" Location = { "bounds" : { "northeast" : { "lat" : 44.9483849, "lng" : -93.1261959 }, "southwest" : { "lat" : 44.9223829, "lng" : -93.200307 } }, "location" : { "lat" : 44.9330076, "lng" : -93.16290629999999 }, "location_type" : "APPROXIMATE", "viewport" : { "northeast" : { "lat" : 44.9483849, "lng" : -93.1261959 }, "southwest" : { "lat" : 44.9223829, "lng" : -93.200307 } } }