我有问题。我正在 Eclipse IDE 中开发 Web 应用程序并使用 Tomcat 7。
一切工作正常，突然我的调试器不再正常工作，一切都崩溃了。我一直在寻找同样的错误，但我还没有找到解决方案。请帮我。
我收到此错误：
SEVERE: Servlet.service() for servlet [FitbitApiAuthExampleServlet] in context with path [/Webfit] threw exception
java.lang.NullPointerException
at java.net.URLEncoder.encode(Unknown Source)
at com.fitbit.api.client.http.OAuth.encode(OAuth.java:254)
at com.fitbit.api.client.http.OAuth.encodeParameters(OAuth.java:233)
at com.fitbit.api.client.http.OAuth.encodeParameters(OAuth.java:217)
at com.fitbit.api.client.http.OAuth.normalizeRequestParameters(OAuth.java:196)
at com.fitbit.api.client.http.OAuth.generateAuthorizationHeader(OAuth.java:85)
at com.fitbit.api.client.http.OAuth.generateAuthorizationHeader(OAuth.java:129)
at com.fitbit.api.client.http.HttpClient.setHeaders(HttpClient.java:522)
at com.fitbit.api.client.http.HttpClient.httpRequest(HttpClient.java:422)
at com.fitbit.api.client.http.HttpClient.get(HttpClient.java:398)
at com.fitbit.api.client.FitbitApiClientAgent.httpGet(FitbitApiClientAgent.java:2563)
at com.fitbit.api.client.FitbitApiClientAgent.httpGet(FitbitApiClientAgent.java:2513)
at com.fitbit.api.client.FitbitApiClientAgent.getLoggedHeartRate(FitbitApiClientAgent.java:1779)
at com.fitbit.web.FitbitApiAuthExampleServlet.doGet(FitbitApiAuthExampleServlet.java:108)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
小服务程序代码：
package com.fitbit.web;
import com.fitbit.api.FitbitAPIException;
import com.fitbit.api.client.*;
import com.fitbit.api.client.service.FitbitAPIClientService;
import com.fitbit.api.common.model.body.Body;
import com.fitbit.api.common.model.body.BodyWithGoals;
import com.fitbit.api.common.model.bp.Bp;
import com.fitbit.api.common.model.heart.Heart;
import com.fitbit.api.common.model.user.UserInfo;
import com.fitbit.api.model.APIResourceCredentials;
import com.fitbit.api.model.FitbitUser;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.joda.time.LocalDate;
import java.io.IOException;
import java.util.Properties;
/**
* Created by IntelliJ IDEA.
* User: Kiryl
* Date: 6/22/11
* Time: 7:05 AM
*/
public class FitbitApiAuthExampleServlet extends HttpServlet {
public static final String OAUTH_TOKEN = "oauth_token";
public static final String OAUTH_VERIFIER = "oauth_verifier";
private FitbitAPIEntityCache entityCache = new FitbitApiEntityCacheMapImpl();
private FitbitApiCredentialsCache credentialsCache = new FitbitApiCredentialsCacheMapImpl();
private FitbitApiSubscriptionStorage subscriptionStore = new FitbitApiSubscriptionStorageInMemoryImpl();
private String apiBaseUrl;
private String fitbitSiteBaseUrl;
private String exampleBaseUrl;
private String clientConsumerKey;
private String clientSecret;
private FitbitUser fitbitUser = new FitbitUser("-");
private int year = 2012;
private int month = 5;
private int day = 5;
public void init(ServletConfig config) throws ServletException {
super.init(config);
try {
Properties properties = new Properties();
properties.load(getClass().getClassLoader().getResourceAsStream("config.properties"));
apiBaseUrl = properties.getProperty("apiBaseUrl");
fitbitSiteBaseUrl = properties.getProperty("fitbitSiteBaseUrl");
exampleBaseUrl = properties.getProperty("exampleBaseUrl").replace("/app", "");
clientConsumerKey = properties.getProperty("clientConsumerKey");
clientSecret = properties.getProperty("clientSecret");
} catch (IOException e) {
throw new ServletException("Exception during loading properties", e);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
FitbitAPIClientService<FitbitApiClientAgent> apiClientService = new FitbitAPIClientService<FitbitApiClientAgent>(
new FitbitApiClientAgent(apiBaseUrl, fitbitSiteBaseUrl, credentialsCache),
clientConsumerKey,
clientSecret,
credentialsCache,
entityCache,
subscriptionStore
);
if (request.getParameter("completeAuthorization") != null) {
// Get temporary token and verifier returned by Fitbit from query string
String tempTokenReceived = request.getParameter(OAUTH_TOKEN);
String tempTokenVerifier = request.getParameter(OAUTH_VERIFIER);
// Fetch user credentials from cache by temporary token from query string
APIResourceCredentials resourceCredentials = apiClientService.getResourceCredentialsByTempToken(tempTokenReceived);
/*Handle error when there is no record of credentials in cache for the temporary token provided
As implementation of the credentials cache in this example is not persistant,
this error will popup if you restart application, while user's browser will be on Fitbit*/
if (resourceCredentials == null) {
throw new ServletException("Unrecognized temporary token when attempting to complete authorization: " + tempTokenReceived);
}
// Call method of Fitbit4J to get token credentials only if necessary (they haven't been cached yet)
if (!resourceCredentials.isAuthorized()) {
resourceCredentials.setTempTokenVerifier(tempTokenVerifier); // The verifier token is required in the request to get token credentials
try {
apiClientService.getTokenCredentials(new LocalUserDetail(resourceCredentials.getLocalUserId())); // get token credentials for user
} catch (FitbitAPIException e) {
throw new ServletException("Unable to finish authorization with Fitbit.", e);
}
}
try {
// get UserInfo
UserInfo userInfo = apiClientService.getClient().getUserInfo(new LocalUserDetail(resourceCredentials.getLocalUserId()));
request.setAttribute("userInfo", userInfo);
//get HeartRate
Heart heartInfo = apiClientService.getClient().getLoggedHeartRate(new LocalUserDetail(resourceCredentials.getLocalUserId()), fitbitUser, new LocalDate(year,month,day));
//HeartRate heartAverage = new HeartRate(heartInfo.getTrackerAverage());
request.setAttribute("heartRate", heartInfo);
/*double weight = apiClientService.getClient().getWeight(new LocalUserDetail(resourceCredentials.getLocalUserId()), new FitbitUser("-"), new LocalDate(2012,5,5));
request.setAttribute("weight", weight);*/
// get BodyInfo (weight, fat, bmi)
Body bodyInfo = apiClientService.getClient().getBody(new LocalUserDetail(resourceCredentials.getLocalUserId()), fitbitUser, new LocalDate(year,month,day));
//BodyWithGoals bodyGoals = apiClientService.getClient().getBodyWithGoals(new LocalUserDetail(resourceCredentials.getLocalUserId()), new FitbitUser("-"), new LocalDate(year,month,day));
request.setAttribute("bodyInfo", bodyInfo);
// get BloodPressure (BP) Info
Bp bloodPressureInfo = apiClientService.getClient().getLoggedBp(new LocalUserDetail(resourceCredentials.getLocalUserId()), fitbitUser, new LocalDate(year,month,day));
request.setAttribute("bloodPressureInfo", bloodPressureInfo);
// forward result to .jsp page
request.getRequestDispatcher("/fitbitApiAuthExample.jsp").forward(request, response);
} catch (FitbitAPIException e) {
throw new ServletException("Exception during getting user info", e);
}
} else {
try {
response.sendRedirect(apiClientService.getResourceOwnerAuthorizationURL(new LocalUserDetail("-"), exampleBaseUrl + "/fitbitApiAuthExample?completeAuthorization="));
} catch (FitbitAPIException e) {
throw new ServletException("Exception during performing authorization", e);
}
}
}
}