java - Android应用-无法启动 Activity ComponentInfo

Question

我创建了一个应用程序，该应用程序应该从我的Thingspeak channel 接收数据。
首先，我只是使用了webview小部件，但我想走得更远，并使用Thingspeak Java api自己处理数据。

在MainActivity中，我只是输入以下代码:

Channel channel = new Channel(1234,"writeKey");
try {
    Entry entry = channel.getLastChannelEntry();
} catch (UnirestException e) {
    e.printStackTrace();
} catch (ThingSpeakException e) {
    e.printStackTrace();
}
    out.println("entry");

但我得到以下错误:

java.lang.RuntimeException: Unable to start activity ComponentInfo{de.babytemp.babytempapp2/de.babytemp.babytempapp2.MainActivity}: java.lang.IllegalArgumentException: Unknown pattern character 'X'
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
                                              Caused by: java.lang.IllegalArgumentException: Unknown pattern character 'X'
at java.text.SimpleDateFormat.validatePatternCharacter(SimpleDateFormat.java:314)
at java.text.SimpleDateFormat.validatePattern(SimpleDateFormat.java:303)
at java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:356)
at com.google.gson.DefaultDateTypeAdapter.<init>(DefaultDateTypeAdapter.java:49)
at com.google.gson.GsonBuilder.addTypeAdaptersForDate(GsonBuilder.java:555)
at com.google.gson.GsonBuilder.create(GsonBuilder.java:543)
at de.babytemp.babytempapp2.Channel.<init>(Channel.java:46)
at de.babytemp.babytempapp2.MainActivity.onCreate(MainActivity.java:41)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
at android.app.ActivityThread.access$800(ActivityThread.java:151) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5254) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

谢谢!

Answer 1

package de.babytemp.babytempapp2;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.JsonNode;
import com.mashape.unirest.http.Unirest;
import com.mashape.unirest.http.exceptions.UnirestException;
import com.mashape.unirest.request.GetRequest;
import java.util.HashMap;

public class Channel {

private String APIURL = "http://api.thingspeak.com";
private static final String APIHEADER = "XXXXXXXXX";
private final Integer channelId;
private String readAPIKey;
private String writeAPIKey;
private final Boolean isPublic;
private final HashMap<String, Object> fields = new HashMap<>();
private final Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd'T'HH:mm:ss").create();

/**
 * Constructor for a public, read-only, Thingspeak channel. This type of
 * channel cannot be updated.
 *
 * @param channelId Channel Id.
 */
public Channel(Integer channelId) {
    this.isPublic = true;
    this.channelId = channelId;
}

/**
 * Constructor for a public, writeable, Thingspeak channel.
 *
 * @param channelId Channel Id.
 * @param writeKey API Key for the channel. See
 * https://thingspeak.com/channels/<channelId>#apikeys
 */
public Channel(Integer channelId, String writeKey) {
    this.isPublic = true;
    this.channelId = channelId;
    this.writeAPIKey = writeKey;
}

/**
 * Constructor for a private, writeable, Thingspeak channel.
 *
 * @param channelId Channel Id.
 * @param writeKey Write API Key. See
 * https://thingspeak.com/channels/<channelId>#apikeys.
 * @param readKey Read API Key. See
 * https://thingspeak.com/channels/<channelId>#apikeys.
 */
public Channel(Integer channelId, String writeKey, String readKey) {
    this.channelId = channelId;
    this.readAPIKey = readKey;
    this.writeAPIKey = writeKey;
    this.isPublic = false;
}

/**
 * Make GET requests to the Thingspeak API without additional feed
 * parameters.
 *
 * @param url The API url.
 * @return JSON string.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
private String thingRequest(String url) throws UnirestException, ThingSpeakException {
    GetRequest request = Unirest.get(url);
    if (!this.isPublic) {
        request.field("key", this.readAPIKey);
    }
    HttpResponse<JsonNode> response = request.asJson();
    if (response.getCode() != 200) {
        throw new ThingSpeakException("Request failed with code " + response.getCode());
    }
    return response.getBody().toString();
}

/**
 * Make GET requests to the Thingspeak API with additional feed parameters.
 *
 * @param url The API url.
 * @param options Optional feed parameters.
 * @return JSON string.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
private String thingRequest(String url, FeedParameters options) throws UnirestException, ThingSpeakException {
    GetRequest request = Unirest.get(url);
    if (!this.isPublic) {
        request.field("key", this.readAPIKey);
    }
    request.fields(options.fields);
    HttpResponse<JsonNode> response = request.asJson();
    if (response.getCode() != 200) {
        throw new ThingSpeakException("Request failed with code " + response.getCode());
    }
    return response.getBody().toString();
}

/**
 * Use a server other than thingspeak.com. If you are hosting your own
 * Thingspeak server, set the url of the server here.  The url of the public
 * Thingspeak server is http://api.thingspeak.com
 *
 * @param url eg. http://localhost, http://thingspeak.local:3000, etc.
 */
public void setUrl(String url) {
    this.APIURL = url;
}

/**
 * Update channel with new data.
 *
 * @param entry The new data to be posted.
 * @return The id of the new entry.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Integer update(Entry entry) throws UnirestException, ThingSpeakException {
    HttpResponse<String> response = Unirest.post(APIURL + "/update")
            .header(APIHEADER, this.writeAPIKey)
            .header("Connection", "close")
            .fields(entry.getUpdateMap())
            .asString();
    if (response.getCode() != 200) {
        throw new ThingSpeakException("Request failed with code " + response.getCode());
    } else if (response.getBody().equals("0")) {
        throw new ThingSpeakException("Update failed.");
    }
    return Integer.parseInt(response.getBody());
}

/**
 * Get a channel feed with default feed options. Does not include location or status info. Only fields that
 * have been named in the channel's settings (via the web) will be returned.
 *
 * @return Feed for this channel.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getChannelFeed() throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/feed.json";
    return gson.fromJson(thingRequest(url), Feed.class);
}

/**
 * Get a channel feed with additional feed options. Only fields that have been named in
 * the channel's settings (via the web) will be returned.
 *
 * @param options Additional feed parameters.
 * @return Feed for this channel.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getChannelFeed(FeedParameters options) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/feed.json";
    return gson.fromJson(thingRequest(url, options), Feed.class);
}

/**
 * Get last entry in this channel with default feed options. This is a
 * faster alternative to getting a Channel Feed and then calling
 * {@link Feed#getChannelLastEntry()}.
 *
 * @return Entry.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Entry getLastChannelEntry() throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/feed/last.json";
    return gson.fromJson(thingRequest(url), Entry.class);
}

/**
 * Get last entry in this channel with additional feed options. This is a
 * faster alternative to getting a Channel Feed and then calling
 * {@link Feed#getChannelLastEntry()}
 *
 * @param options
 * @return Entry.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Entry getLastChannelEntry(FeedParameters options) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/feed/last.json";
    return gson.fromJson(thingRequest(url, options), Entry.class);
}

/**
 * Get a field feed with default feed options.
 *
 * @param fieldId The field to include in the field (1-8).
 * @return Feed.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getFieldFeed(Integer fieldId) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/field/" + fieldId + ".json";
    return gson.fromJson(thingRequest(url), Feed.class);
}

/**
 * Get a field feed with additional feed options.
 *
 * @param fieldId The field to include in the field (1-8).
 * @param options Optional parameters that control the format of the feed.
 * @return Feed.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getFieldFeed(Integer fieldId, FeedParameters options) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/field/" + fieldId + ".json";
    return gson.fromJson(thingRequest(url, options), Feed.class);
}

/**
 * Get the last entry in a field feed with default feed options. 
 *
 * @param fieldId The field to return (0-8).
 * @return Last entry for the specified field.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Entry getLastFieldEntry(Integer fieldId) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/field/" + fieldId + "/last.json";
    return gson.fromJson(thingRequest(url), Entry.class);
}

/**
 * Get the last entry in a field feed with additional feed options.     
 *
 * @param fieldId The field to return (0-8).
 * @param options Supported options: offset, status, and location.
 * @return Last entry for the specified field.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Entry getLastFieldEntry(Integer fieldId, FeedParameters options) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/field/" + fieldId + "/last.json";
    return gson.fromJson(thingRequest(url, options), Entry.class);
}

/**
 * Get channel status updates. Uses the default feed options.
 *
 * @return Status feed.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getStatusFeed() throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/status.json";
    return gson.fromJson(thingRequest(url), Feed.class);
}

/**
 * Get channel status updates.
 *
 * @param options Only {@link FeedParameters#offset(java.lang.Integer)} is
 * supported.
 * @return Status feed.
 * @throws UnirestException The request cannot be made.
 * @throws ThingSpeakException The request is invalid.
 */
public Feed getStatusFeed(FeedParameters options) throws UnirestException, ThingSpeakException {
    String url = APIURL + "/channels/" + this.channelId + "/status.json";
    return gson.fromJson(thingRequest(url, options), Feed.class);
}

}