nullpointerexception

问题 I am getting this error Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.webkit.WebView.loadUrl when I try to load a webview inside a dialog in android.I have attached the log and code and I have used below. Kindly provide your knowledge to solve it. 02-06 18:07:41.605: E/AndroidRuntime(1492): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanas.activities/com.tanas.activities.ContactInfoActivity}: java.lang.NullPointerException

问题 I am using this code to pull my string array from my values folder: String achievementNames[] = getResources().getStringArray(R.array.achieveString); String achievementDescriptions[] = getResources().getStringArray(R.array.achieveDescript); However, when I run this, it gives me a null pointer exception on those lines of code. Is there a better way to pull string arrays or is there an error in my code? 回答1: You shouldn't call getResources() unless onCreate() callback has been triggered. public

问题 I'm using MS Visual Studio 2015 to develop a small app using VC++ and backend as SQLite . However using standard SQLite3 C api there are no exceptions occurring. But when i tried to make a small wrapper for using SQLite. I made one header file for simplification for using functions as SQLite APIs. I'm getting read access violation exception. How to handle this exception and what changes i should make in my small wrapper so i can use it in multiple modules of the app. here is my small wrapper

问题 Im allocating memory to a double pointer in another function, therefore I need to use a pointer to the pointer to the pointer. Im getting an exception thrown when i use sscanf, im not sure exactly why. Heres a snippet of the code. This was working earlier when it was all in the same function and i only needed to use double pointers, but now that im refactoring the code and using triple pointers im having this issue. typedef float vector[3] int mainLoaderFunc() { char* memory = NULL; size_t

问题 I made an activity "Messages" which is supposed to get JSON data from a given URL. I tried making a loop to print the json data, but the problem was somewhere else. I am getting NullPointerException on the JSONArray , "json". Messages class: public class Messages extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); TextView tv = (TextView) findViewById(R.id.tv_messages); JSONArray json = JSONfunctions.getJSONfromURL("http://docs

问题 I apologize if this has been answered in some way somewhere else, but I'm not well enough versed in java to identify a similar problem from some other situation. It might be tough to get all the information here, so I'll try to get the essentials in. I'm writing a Calendar program, and when I call the constructor in the demo class: System.out.println("Enter month (1 - 12)"); month = console.nextInt(); System.out.println("Enter year (> 1500)"); year = console.nextInt(); Calendar myCalendar =

问题 I have a form in my application for which I'm trying to validate that the userName and/or email is not already on the DB. This is service class: @Stateless public class CustomerFacade extends AbstractFacade<Customer> { @PersistenceContext(unitName = "OnlineStorePU") private EntityManager em; @Override protected EntityManager getEntityManager() { return em; } public CustomerFacade() { super(Customer.class); } } This is the entity class: @Entity @Table(name = "customer") @XmlRootElement

问题 The following code is a snippet of a program I am getting a nullpointer exception from. When I press the "Add" button on the GUI, an error message pointing to this line: buttonPanel.addButton.setEnabled(false); is displayed. I'm guessing that the addButton is null for some reason although I instantiated it in the constructor of buttonPanel: addButton = new JButton("Add"); addButton.addActionListener(buttonListener); Why is the null pointer error Exception in thread "AWT-EventQueue-0" java

问题 Background: I just want to create a customDialog with a specific layout and add the content. Its a DialogFragment Code: TextView text; @Override public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); text = (TextView)getView().findViewById(R.id.lorem); text.setText("Test"); } @Override public Dialog onCreateDialog(Bundle savedInstanceState){ AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); LayoutInflater inflater = getActivity()

问题 The Jmeter script runs fine on apache-jmeter2.8. I upgraded recently to apache-jmeter-2.10 and I started getting Null Point exception. I revert back to apache-jmeter2.8 and the script works fine. java.lang.NullPointerException at org.apache.jorphan.util.JOrphanUtils.replaceAllChars(JOrphanUtils.java:264) at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.encodeSpaces(HTTPSamplerBase.java:1332) at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.followRedirects(HTTPSamplerBase