HttpClient

Download the precompiled plugin file under DolphinDBPlugin/httpClient/bin/linux64. Load the plugin with the following command in DolphinDB:

loadPlugin("/path/to/PluginHttpClient.txt");

This plugin uses the libcurl library. If the message "curl return: error setting certificate verify locations: CAfile: /etc/ssl/certs/ca-certificates.crt CApath: none" is displayed when visiting an HTTPS website, it's because cURL expects the certificate to be at the default path. Please download the root certificate for cURL using this command:

wget https://curl.haxx.se/ca/cacert.pem

Then place the downloaded file under the default directory as mentioned in the error message.

Prerequisites: The static libraries of libcurl, libssl(version 1.0.1 on ARM; version 1.0.2 on x86), libcrypto(version 1.0.1 on ARM; version 1.0.2 on x86) and libz are available.

Send HTTP GET request.

Syntax

httpClient::httpGet(url, [params], [timeout], [headers])

Arguments

• url: a string indicating the URL of HTTP request.
• params: a string or dict (whose keys and values are strings) to send in the HTTP request. For example, suppose url is specified as "www.dolphindb.com":
  • if params is a string (e.g., "example"), the URL of the HTTP request would be "www.dolphindb.com?example";
  • if params is a dictionary (e.g., with 2 key-value pairs "name"->"ddb" and "id"->"111"), the URL of the HTTP request would be "www.dolphindb.com?id=111&name=ddb".
• timeout: a non-negative integer indicating the the maximum time in milliseconds that an HTTP request can take. Default timeout is 0 which means it never times out during transfer.
• headers: a string or dict (whose keys and values are strings) indicating the headers of the HTTP request.
  • If it's a dictionary (e.g., with 2 key-value pairs "groupName"->"dolphindb" and "groupId"->"11"), two headers "groupId:11" and "groupName:dolphindb" will be added to the HTTP request ;
  • If it's a string, it must have the pattern <key>:<value> and it will be added as a header to the request.

Return

A dictionary object containing following keys:

• responseCode: HTTP status code
• headers: HTTP response header
• text: HTTP response body
• elapsed: HTTP request elapsed time

Example

loadPlugin('/home/zmx/worker/DolphinDBPlugin/httpClient/PluginHttpClient.txt');
param=dict(string,string);
header=dict(string,string);
param['name']='zmx';
param['id']='111';
header['groupName']='dolphindb';
header['groupId']='11';
//Please set up your own httpServer ex.(python -m SimpleHTTPServer 8900)
url = "localhost:8900";
res = httpClient::httpGet(url,param,1000,header);

Send HTTP POST request.

Syntax

httpClient::httpPost(url, [params], [timeout], [headers])

Arguments

• url: a string indicating the URL of HTTP request.
• params: a string or dict (whose keys and values are strings) to send in the HTTP request. For example, suppose url is specified as "DolphinDB - High Performance Time-series Database ":
  • if params is a string (e.g., "example"), the URL of the HTTP request would be "www.dolphindb.com?example";
  • if params is a dictionary (e.g., with 2 key-value pairs "name"->"ddb" and "id"->"111"), the URL of the HTTP request would be "www.dolphindb.com?id=111&name=ddb".
• timeout: a non-negative integer indicating the the maximum time in milliseconds that you allow the HTTP request to take. Default timeout is 0 which means it never times out during transfer.
• headers: a string or dict (whose keys and values are strings) indicating the headers of the HTTP request.
  • If it's a dictionary (e.g., with 2 key-value pairs "groupName"->"dolphindb" and "groupId"->"11"), two headers "groupId:11" and "groupName:dolphindb" will be added to the HTTP request ;
  • If it's a string, it must have the pattern <key>:<value> and it will be added as a header to the request.

Return

A dictionary object containing following keys:

• responseCode: HTTP status code
• headers: HTTP response header
• text: HTTP response body
• elapsed: HTTP request elapsed time

Example

loadPlugin('/home/zmx/worker/DolphinDBPlugin/httpClient/PluginHttpClient.txt');
param=dict(string,string);
header=dict(string,string);
param['name']='zmx';
param['id']='111';
header['groupName']='dolphindb';
header['groupId']='11';
//Please set up your own httpServer e.g. (python -m SimpleHTTPServer 8900)
url = "localhost:8900";
res = httpClient::httpPost(url,param,1000,header);

Configure the email server.

Note: To send email using the httpClient plugin, the SMTP service on your mail account must be enabled.

Syntax

httpClient::emailSmtpConfig(emailName,host,post)

Arguments

• emailName: a string indicating the domain name in your email address. For example, "gmail.com" or "yahoo.com".
• host: a string indicating your SMTP server address.
• port: an integer (INT) indicating the port number of your email server. If this parameter is unspecified, it takes the default value of 25.

Examples

emailName="example.com";
host="smtp.example.com";
port=25;
httpClient::emailSmtpConfig(emailName,host,port);