Question

我正在使用名为Mirth（版本3.6）的产品来执行转换代码。它似乎没有交互式调试器，因此谁能解释为什么目标转换中的以下代码仅从IF语句而不是SWITCH语句记录？可以在Eclipse中运行的常规Java上完美运行，但是此代码是在Mirth使用的JavaScript引擎（如果我没记错的话，是Rhino）内执行的。

for each (node in msg['PID'].children()) 
{
    if(node.name() == "PID.3")
        {
        logger.info("IF Succeeded");
    }

    switch(node.name())
    {
        case "PID.3": 
             logger.info("SWITCH Succeeded"); // This line never logs
             break;
    }
}

Answer 1

这是Mirth Connect的常见问题，因为它使用Rhino作为引擎（使用Java和JavaScript）。 Switch语句不适用于Java String对象简单的解决方案是通过将空字符串连接到可疑字符串（即str +''）来将任何未知的字符串类型转换为本地JS字符串

// See in action
for each (node in msg['PID'].children()) 
{
    var nodeName = node.name();
    if (nodeName != "PID.3")
    {
       continue;
    }
    var type = typeof(nodeName);

    logger.debug('NodeName: ' + nodeName + '; Type: ' + type);
    if (type == 'object') {
        logger.debug('Type is object');
        if (nodeName instanceof String) {
            logger.debug('Object is Java String instance');
        } else {
            logger.debug('Object is not Java String instance');
        }
    } else if (type === 'string') {
        logger.debug('Type is JS string.');
    } else {
        logger.debug('Type is not object or string. Type: ' + type);
    }

    // Works with String object or JS string
    if (nodeName == "PID.3")
    {
       logger.info("IF Succeeded");
    }

    // Only works with JS string
    switch (nodeName)
    {
        case "PID.3": 
            logger.info("SWITCH Succeeded"); // This line never logs
            break;
        default:
            logger.info("SWITCH not matched: " + nodeName);
            break;
    }

    logger.debug('Convert to JS string');
    nodeName = nodeName + '';
    type = typeof(nodeName);
    logger.debug('Converted Type: ' + type);
    if (type == 'object') {
        logger.debug('Converted Type is object');
        if (nodeName instanceof String) {
            logger.debug('Converted Object is String instance');
        } else if (nodeName instanceof string) {
            logger.debug('Converted Object is string instance');
        } else {
            logger.debug('Converted Object is not Java String instance');
        }
    } else if (type === 'string') {
        logger.debug('Converted Type is JS string.');
    } else {
        logger.debug('Converted Type is not object or string. Type: ' + type);
    }

    switch(nodeName)
    {
        case "PID.3": 
            logger.info("SWITCH with js string Succeeded");
            break;
        default:
            logger.info("SWITCH with js string not matched: " + nodeName);
            break;
    }
    break;
}

傻事：逃避SWITCH与IF声明

1 个答案: