# Java Transformer Module configuration

The Java Transformer Module (JTM) is Transformer’s in-built support for running custom modules that you’ve developed in Java using Transformer’s [Java Module API,opts="nofollow"](https://docs.caplin.com/developer/api/transformer_java_sdk/6/). The following configuration items can be used to set up some standard features of a custom Java module that runs under the JTM.

**📌 NOTE**\
In the [Caplin Platform Deployment Framework](../deployment-framework/index.md), add the configuration items described here to the configuration file `<Framework-root>/global-config/overrides/<Java-module-name>/Transformer/etc/jtm.conf` where `<Framework-root>` is the Deployment Framework’s topmost directory and `<Java-module-name>` is the name of the Java module you’ve developed.

**💡 TIP**\
When developing a Java-based module, you also need to configure Transformer to recognise it. This is explained in detail in How can I... [Create a Java-based Transformer Service blade](../deployment-framework/cdf-create-a-java-based-transformer-service-blade.md).

## ignore-wildcards

`ignore-wildcards` specifies that when this custom Java module subscribes to a subject that has regular expression wildcard characters in the subject name, the wildcards are treated as normal characters by the listener that receives updates for the subscription.

When a Java module subscribes to a subject, it can supply the subject as a wildcard pattern, containing regular expression wildcard characters such as `*` (match any number of characters) and `?` (match a single character). For example, it could subscribe to the subject `/A/B/X*Y?`

The listener that’s set up for the subscription accepts incoming updates according to whether or not their subjects match the wildcards. For example, if the subscription is for `/A/B/X*Y?`, updates for the subjects `/A/B/XZZZY1` and `/A/B/XZY2` are accepted for processing by the module, but not updates for `/A/B/CZZZY23`.

When you set `ignore-wildcards` to `TRUE`, you turn off the update listener’s wildcard feature and the listener therefore treats the wildcard characters in the subject name as normal characters. So for the subscription to `/A/B/X*Y?`, the listener would only accept updates to the subject `/A/B/X*Y?`

**Syntax:** `ignore-wildcards <boolean>`

**Type:** boolean

**Default value:** `FALSE` (wildcard characters in the subscribed subject are treated as such when listening for updates)

## module-classid

`module-classid` specifies the class ID of the Java module. This must be the same as the [`class-id`](../datasource/datasource-java-jvm-configuration.md#class-id) option of the [`add-javaclass`](../datasource/datasource-java-jvm-configuration.md#add-javaclass) configuration item for this Java module in the Transformer’s `java.conf` configuration file.

**Syntax:** `module-classid <java-class-id>`

**Type:** string

**Default value:** `jtm`

**Example:**

In `java.conf`:

```
add-javaclass
   ...
  class-id ExampleJavaModule
   ...
end-javaclass
```

In the Java module’s configuration file:

```
module-classid ExampleJavaModule
```

## module-logfile

`module-logfile` specifies the name, and optionally the directory path, of the log file to which this Java module’s events are logged.

The filename can contain the `%h` parameter, which is replaced at run time by the host name of the machine on which the Transformer is running.

The directory path can contain the `%r` and `%a` parameters. At run time, `%r` is replaced by the root directory ([`application-root`](../datasource/datasource-run-time-environment-configuration.md#application-root)) under which the Transformer runs, and `%a` is replaced by the Transformer’s DataSource [`application-name`](../datasource/datasource-run-time-environment-configuration.md#application-name).

Also see [`log-level`](#log-level).

**Syntax:** `module-logfile <directory-path-and-filename>`

**Type:** string

**Default value:** `<Java-module-name>.log` For example, `jtm.log`

## module-multi-request

`module-multi-request` specifies when `TRUE` that the request and discard callbacks implemented by registered data providers can be called multiple times. A Java module can register multiple DataProviders for different subjects using an implementation of the `[DataProviderRegistrar,opts="nofollow"](https://docs.caplin.com/developer/api/transformer_java_sdk/6/com/caplin/transformer/module/DataProviderRegistrar.html)` interface.The provider callbacks are the `request()` and `discard()` methods of the module’s implementation of the `[DataProvider,opts="nofollow"](https://docs.caplin.com/developer/api/transformer_java_sdk/6/com/caplin/transformer/module/DataProvider.html)` interface. For more about this, see the [Transformer Java Module API Documentation,opts="nofollow"](https://docs.caplin.com/developer/api/transformer_java_sdk/6/).

**Syntax:** `module-multi-request <boolean>`

**Type:** boolean

**Default value:** `FALSE` (the module’s provider callbacks are only called _once_ for each request or discard)

## log-level

`log-level` specifies the severity of the errors and events that this Transformer reports to the Java module’s log file (see [`module-logfile`](#module-logfile)).

**Syntax:** `log-level <log-level-name>`

**Type:** string

**Default value:** `INFO`

**Values accepted:**

| log-level-name | DESCRIPTION |
| --- | --- |
| `DEBUG` | Reports all errors and events. |
| `INFO` | Reports events and information regarding normal operation of the Java module, and all errors included in the `WARN`, `NOTIFY`, `ERROR` and `CRIT` log levels. |
| `WARN` | Reports minor errors and all errors included in the `NOTIFY`, `ERROR` and `CRIT` log levels. |
| `NOTIFY` | Reports errors regarding data corruptions and all errors included in the `ERROR` and `CRIT` log levels. |
| `ERROR` | Reports serious errors and all errors included in the `CRIT` log level. |
| `CRIT` | Reports critical errors that prevent the Java module from running. |

---

**See also:**

* How can I... [Create a Java-based Transformer Service blade](../deployment-framework/cdf-create-a-java-based-transformer-service-blade.md)
* Reference: [Transformer Java Module API Documentation,opts="nofollow"](https://docs.caplin.com/developer/api/transformer_java_sdk/6/)