Use Regexp to extract values, and make JQL queries to locate an existing issue

This example shows what can be done with a bit more time to develop a script. This example includes use of regular expressions to extract values from the email, and searching with a JQL query to find an existing Jira issue. It results in a behaviour similar to the Regexp Field Processor.

Implementation SINCE 3.4.11, 4.0.17, 4.1.8

Following the release of JEMH 3.4.11, 4.0.17, and 4.1.8 the utils class jemhThreadUtils has been added to the Scripting context and adds some methods that help reduce complexity of Issue Association via Script. The following example script can be used in place of the legacy implementations.

// For more detail and background information regarding this Script please see the following Documentation: https://thepluginpeople.atlassian.net/l/cp/CZKAm2Vw
// Create Regexp pattern to extract external id
var pattern = Java.type("java.util.regex.Pattern").compile("Case\\s#:\\s([0-9]+)");
var matcher = pattern.matcher(body);
var foundExternalId = "";

// Set the value of the Custom Field which will hold the External ID value on the Issue
var externalIDField = "customfield_10122";
 
// If able to extract issue key, set variable
if (matcher.find()) {
    var group = matcher.group(1);
    if (group) {
        foundExternalId = group;
    }
}
 
var issueWithExternalId = "";
if (foundExternalId) {
    print("external ID extracted: "+foundExternalId);
    
    // Use Thread Utils to find a list of Issues which hold the 'foundExternalId' in the 'externalIDField'. This method will 
    // apply Thread Match conditions defined in the Profile (only match open issues, matches JQL, etc.). 
    // Additionally, the returned list will be ordered by Creation Date (Ascending) therefore the Issue at index 0 would be the oldest valid Issue
    var results = jemhThreadUtils.getFilteredAssociatedIssuesFromExternalId(externalIDField, foundExternalId);
      
    // Get first issue if exists and add via issueKey directive (Could be empty)
    if (results.size()>0) {
        var issue = results[0];
        issueWithExternalId = issue.getKey();
        print("Found issue using External ID match:"+issueWithExternalId);
    } else {
        print("No issues match found using External ID match");
    }
}
 
if (!issueWithExternalId.isEmpty()) {
        resultMap.put("issueKey",issueWithExternalId)
} else if (!foundExternalId.isEmpty()) {
        resultMap.put(externalIDField, foundExternalId);
}

Legacy Implementation

Since JEMH 3.3.21 we lock down access to arbitrary classes in the script context, they cannot be accessed using historic methods:

var filter = PagerFilter.static.getUnlimitedFilter();
var builder = JqlQueryBuilder.static.newBuilder();

but need to be gained through fully specified class names:

var filter = Java.type("com.atlassian.jira.web.bean.PagerFilter").getUnlimitedFilter();
var builder = Java.type("com.atlassian.jira.jql.builder.JqlQueryBuilder").newBuilder();

These specific classes were not initially added, are available since JEMH 3.3.38

Due to issues highlighted on the following page,https://thepluginpeople.atlassian.net/wiki/spaces/JEMH/pages/3974856709/Using+Java+17#Classnotfound-exception-when-using-%E2%80%9Cjava.type%E2%80%9D. It means that if you are using Java 17 with Nashorn installed within jira-install/lib then you will need to use JEMH 4.1.33+ and then use the following instead of lines 20 and 21:

Jira 8.0.0

Do note that getIssues() method is no longer supported on Jira 8.x.x and will trigger a ScriptException. The corresponding method has been renamed to getResults() and it can be used as follows:

Things to change when using this script:

The user object has to be modified to ensure the extraction of the corresponding user who'll be executing this query is successful. The user object is obtained via userManager which in this script gets the admin user (username). Therefore, you need to ensure you are getting the user which exists in your Jira instance.
When building the query object, ensure you are using the relevant custom field type to carry this query out. The custom field type for this query is a Text Field (Single Line). If you have a different custom field type, you'll need to update your query accordingly.
Don't forget to update the field name when building the query object. In this example, we are using the field name but you can also use the field id (customfield_10400). If you have custom fields with duplicate names, you should use field id instead of the name to ensure the JQL query is valid

Refer to following classes for more information: