Question

我创建了一个类，它提供了一个方法来通过REST获取一个JSON对象，然后将其反序列化为LinkedHashMap。方法如下：

 @Override
public LinkedHashMap refreshStatus(String metricType, String metricPeriod) {
    ObjectMapper mapper = new ObjectMapper();
    LinkedHashMap<String,String> map = null;

     try {
        map = mapper.readValue(new File("http://localhost:8081/Metrics/Stats/JSONP/ReceiveData/"+metricType+"/"+metricPeriod+"/?callback="), LinkedHashMap.class);


    } catch (JsonParseException e) {
        e.printStackTrace();
    } catch (IOException e) {
    e.printStackTrace();
}
    return map;
}

当我在浏览器中输入带有一些特定参数的URL时，即

http://localhost:8081/Metrics/Stats/JSONP/ReceiveData/Totals/All/?callback=

我得到一个合适的JSON对象：

{"Boxes":"8","Contracts":"23","Updates":"1","Deactivations":"4","ActiveBoxes":"33","InactiveBoxes":"1","PendingInstallationsContracts":"70","Alerts":"626","PercentsBoxInstalled":"100.0%","Miles":"0"}

然而，当我运行应用程序并调用该方法时，我得到一个FileNotFoudException：

java.io.FileNotFoundException: http:/localhost:8081/Metrics/Stats/JSONP/ReceiveData/Totals/All/?callback= (No such file or directory)

有谁知道问题出在哪里？提前谢谢！

Answer 1

确实无法在您的计算机上找到此文件。您尝试在本地文件系统中创建与实际文件对应的文件对象，并提供URL作为参数而不是文件系统路径。

您实际上想要执行HTTP GET，即执行以下操作。

urlString = "http://localhost:8081/Metrics/Stats/JSONP/ReceiveData/Totals/All/?callback=";
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
map = mapper.readValueconn.getInputStream();

在JSON / REST中使用ObjectMapper的FileNotFoundException

1 个答案: