我需要从我的本地主机获取数据。我的代码如下所示：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
String url = "http://10.0.2.2:8080/";
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
JSONArray value = json.getJSONArray("one");
String output = value.toString();
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(output);
// Set the text view as the activity layout
setContentView(textView);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public class JSONParser {
InputStream is = null;
JSONObject jObj = null;
String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
但是我的应用程序在打开时崩溃。有人可以帮我解决我哪里出错了吗？为了您的信息，我通过使用 web.py 运行 python 脚本来设置本地主机
Logcat 错误如下：
08-03 08:55:47.093: E/AndroidRuntime(797): FATAL EXCEPTION: main
08-03 08:55:47.093: E/AndroidRuntime(797): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.customview/com.example.customview.MainActivity}: android.os.NetworkOnMainThreadException
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread.access$600(ActivityThread.java:141)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.os.Handler.dispatchMessage(Handler.java:99)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.os.Looper.loop(Looper.java:137)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread.main(ActivityThread.java:5041)
08-03 08:55:47.093: E/AndroidRuntime(797): at java.lang.reflect.Method.invokeNative(Native Method)
08-03 08:55:47.093: E/AndroidRuntime(797): at java.lang.reflect.Method.invoke(Method.java:511)
08-03 08:55:47.093: E/AndroidRuntime(797): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-03 08:55:47.093: E/AndroidRuntime(797): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-03 08:55:47.093: E/AndroidRuntime(797): at dalvik.system.NativeStart.main(Native Method)
08-03 08:55:47.093: E/AndroidRuntime(797): Caused by: android.os.NetworkOnMainThreadException
08-03 08:55:47.093: E/AndroidRuntime(797): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
08-03 08:55:47.093: E/AndroidRuntime(797): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
08-03 08:55:47.093: E/AndroidRuntime(797): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
08-03 08:55:47.093: E/AndroidRuntime(797): at libcore.io.IoBridge.connect(IoBridge.java:112)
08-03 08:55:47.093: E/AndroidRuntime(797): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
08-03 08:55:47.093: E/AndroidRuntime(797): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
08-03 08:55:47.093: E/AndroidRuntime(797): at java.net.Socket.connect(Socket.java:842)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
08-03 08:55:47.093: E/AndroidRuntime(797): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
08-03 08:55:47.093: E/AndroidRuntime(797): at com.example.customview.MainActivity$JSONParser.getJSONFromUrl(MainActivity.java:75)
08-03 08:55:47.093: E/AndroidRuntime(797): at com.example.customview.MainActivity.onCreate(MainActivity.java:36)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.Activity.performCreate(Activity.java:5104)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
08-03 08:55:47.093: E/AndroidRuntime(797): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
08-03 08:55:47.093: E/AndroidRuntime(797): ... 11 more