TransformUtil.java 文件源码

/**
 * Gets string arg.
 * <p>
 * If number or date passed, will be coerced to string. Other types such as maps or lists
 * will throw TemplateModelException.
 */
public static String getStringArg(TemplateModel obj, String defaultValue, boolean useDefaultWhenEmpty, boolean nonEscaping) throws TemplateModelException {
    String result = null;
    if (obj instanceof TemplateScalarModel) {
        TemplateScalarModel s = (TemplateScalarModel) obj;
        result = LangFtlUtil.getAsString(s, nonEscaping);
    } else if (obj == null) {
        return defaultValue;
    } else if (obj instanceof TemplateNumberModel || obj instanceof TemplateDateModel) {
        // TODO: optimize this call
        result = LangFtlUtil.execStringBuiltIn(obj, FreeMarkerWorker.getCurrentEnvironment()).getAsString();
    } else {
        throw new TemplateModelException("Expected string model or something coercible to string, but got a " +
                obj.getClass() + " instead");
    }
    if (useDefaultWhenEmpty && result.isEmpty()) {
        return defaultValue;
    }
    return result;
}