net.dankito.utils.localization.SettableEncodingResourceBundleControl.kt Maven / Gradle / Ivy

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Some basic utils needed in many projects

There is a newer version: 1.0.20

package net.dankito.utils.localization


/**
 * 
 *  By default .properties files only supports ISO-8859-1 (Latin-1) as encoding.
 *  To be able to load non Latin-1 characters, a custom ResourceBundle.Control has to be written which reads properties file in other encodings (e.g. UTF-8).
 * 
 *
 * Copied from https://stackoverflow.com/questions/4659929/how-to-use-utf-8-in-resource-properties-with-resourcebundle
 */
open class SettableEncodingResourceBundleControl(private val encoding: String) : java.util.ResourceBundle.Control() {

    @Throws(IllegalAccessException::class, InstantiationException::class, java.io.IOException::class)
    override fun newBundle(baseName: String, locale: java.util.Locale, format: String, loader: ClassLoader, reload: Boolean): java.util.ResourceBundle? {
        // The below is a copyFile of the default implementation.
        val bundleName = toBundleName(baseName, locale)
        val resourceName = toResourceName(bundleName, "properties")

        var bundle: java.util.ResourceBundle? = null
        var stream: java.io.InputStream? = null

        if (reload) {
            val url = loader.getResource(resourceName)
            if (url != null) {
                val connection = url.openConnection()
                if (connection != null) {
                    connection.useCaches = false
                    stream = connection.getInputStream()
                }
            }
        }
        else {
            stream = SettableEncodingResourceBundleControl::class.java.classLoader.getResourceAsStream(resourceName)
        }

        if (stream != null) {
            try {
                // Only this line is changed to make it to read properties files as UTF-8.
                bundle = ThrowNoErrorOnMissingValuePropertyResourceBundle(java.io.InputStreamReader(stream, encoding))
            } finally {
                stream.close()
            }
        }

        return bundle
    }

}