我创建了一个类,它提供了一种通过 REST 获取 JSON 对象的方法,然后将该对象反序列化为 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=
我得到了一个正确的 JSON 对象:
{"Boxes":"8","Contracts":"23","Updates":"1","Deactivations":"4","ActiveBoxes":"33","InactiveBoxes":"1","PendingInstallationsContracts":"70","Alerts":"626","PercentsBoxInstalled":"100.0%","Miles":"0"}
但是,当我运行应用程序并调用该方法时,我收到 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吗?预先感谢!
最佳答案
您的计算机上确实找不到此文件。您尝试在本地文件系统中创建与实际文件相对应的文件对象,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,即执行如下操作。
urlString = "http://localhost:8081/Metrics/Stats/JSONP/ReceiveData/Totals/All/?callback=";
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
map = mapper.readValueconn.getInputStream();
关于java - JSON/REST 中的 ObjectMapper 出现 FileNotFoundException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19097521/