我使用 Google Directions API 来获取位置之间的时间,并且我试图将数据从 URL 获取到 JSON 对象中,以便我可以解析它以获得我需要的数据。网址是:
我使用意图访问此 URL。
String url = "http://maps.googleapis.com/maps/api/directions/json?origin=Chicago,IL&destination=Los+Angeles,CA&waypoints=Joplin,MO|Oklahoma+City,OK&sensor=false"
Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(url));
startActivity(intent);
这会在浏览器中显示 json 数据,我想将其放入 json 对象中,这样我就可以使用我需要的任何数据:
JSONObject durationObject = null;
durationObject = jsonObject.getJSONObject("duration");
我在网上查过这个,但我尝试的一切最终都会崩溃或无法正常工作。下面是一些我尝试过但不起作用的代码。由于执行了 if 语句,因此没有任何内容最终写入 String 结果。
InputStream is = null;
String result = "";
JSONObject jsonObject = null;
try {
HttpClient httpclient = new DefaultHttpClient(); // for port 80 requests!
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
// Read response to string
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"utf-8"),1024);
StringBuilder sb = new StringBuilder();
String line = "";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
if (result.isEmpty()) {
result = "nothing";
Toast msg = Toast.makeText(getBaseContext(), result, Toast.LENGTH_LONG);
msg.show();
}
// Convert string to object
jsonObject = new JSONObject(result);
这是 logcat 输出:
04-16 18:38:42.965: W/dalvikvm(9331): threadid=1: thread exiting with uncaught exception (group=0x40c371f8)
04-16 18:38:42.975: E/AndroidRuntime(9331): FATAL EXCEPTION: main
04-16 18:38:42.975: E/AndroidRuntime(9331): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test/com.example.test.MainActivity}: android.os.NetworkOnMainThreadException
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1968)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1993)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread.access$600(ActivityThread.java:127)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1159)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.os.Handler.dispatchMessage(Handler.java:99)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.os.Looper.loop(Looper.java:137)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread.main(ActivityThread.java:4507)
04-16 18:38:42.975: E/AndroidRuntime(9331): at java.lang.reflect.Method.invokeNative(Native Method)
04-16 18:38:42.975: E/AndroidRuntime(9331): at java.lang.reflect.Method.invoke(Method.java:511)
04-16 18:38:42.975: E/AndroidRuntime(9331): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
04-16 18:38:42.975: E/AndroidRuntime(9331): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
04-16 18:38:42.975: E/AndroidRuntime(9331): at dalvik.system.NativeStart.main(Native Method)
04-16 18:38:42.975: E/AndroidRuntime(9331): Caused by: android.os.NetworkOnMainThreadException
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
04-16 18:38:42.975: E/AndroidRuntime(9331): at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
04-16 18:38:42.975: E/AndroidRuntime(9331): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
04-16 18:38:42.975: E/AndroidRuntime(9331): at java.net.InetAddress.getAllByName(InetAddress.java:220)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
04-16 18:38:42.975: E/AndroidRuntime(9331): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
04-16 18:38:42.975: E/AndroidRuntime(9331): at com.example.test.MainActivity.onCreate(MainActivity.java:93)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.Activity.performCreate(Activity.java:4465)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
04-16 18:38:42.975: E/AndroidRuntime(9331): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932)
04-16 18:38:42.975: E/AndroidRuntime(9331): ... 11 more
我正在研究它,它似乎与启用的严格模式有关。有关如何解决此问题的任何帮助都会很棒。