nullpointerexception

问题 I am attempting to use Picasso from Square to pull a jpg from a URL and then append to an EditText. The reason for Picasso is that it's very lightweight in the implementation. As can be seen I am using a placeholder ImageView, whereby Picasso will import the image from the URL provided, and then I convert that ImageView into a Drawable. The same goes for the ImageGetter. However I receive null pointer error when using the configuration below. (Note when simply using a drawable from the

问题 I am following the zetcode Snake java games tutorial and always get this error: ImageIcon iid = new ImageIcon(this.getClass().getResource("ball.png")); ball = iid.getImage(); Exception in thread "main" java.lang.NullPointerException at javax.swing.ImageIcon.<init>(Unknown Source) at snake2.Board.<init>(Board.java:52) at snake2.Snake.<init>(Snake.java:10) at snake2.Snake.main(Snake.java:22) I actually just copied and pasted the code to see how it works. They are in the right packages too; but

问题 In a class i am adding a Fragment programatically. This Fragment contains a Button, which i want to have an onClick implementation. Here is the class i have: public class ShareProduct extends SherlockFragmentActivity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.share_product); FragmentManager fragmentManager = getSupportFragmentManager(); final FragmentTransaction fragmentTransaction = fragmentManager .beginTransaction();

问题 I am trying to download the image from this url: https://hme_player_pictures.s3.amazonaws.com/test-512813ed3b83286c72f376c7-thumb100.jpg here is stack trace: 03-21 12:58:04.040: W/System.err(7084): java.lang.NullPointerException 03-21 12:58:04.040: W/System.err(7084): at libcore.net.http.HttpConnection$Address.hashCode(HttpConnection.java:343) 03-21 12:58:04.045: W/System.err(7084): at java.util.HashMap.get(HashMap.java:298) 03-21 12:58:04.050: W/System.err(7084): at libcore.net.http

问题 I wrote a program to find file or directory. Its working properly when i am trying to Search file with in Directory example java FileSearch abc.txt f:\xyz But when i am try to search file from local drive than program throw Exception java FileSearch abc.txt f:\ after Showing all the search result throws NullPointerException. code is : import java.io.*; class FileSearch{ static String fd; static boolean flg=true; public static void main(String arr[]){ fd=arr[0]; String path=arr[1]; String dir[

问题 I have code similar to the following :- class A { private HashMap<Character, Boolean> myMap; public A() { myMap = new HashMap<Character, Boolean>(); String mychars = "asdfzxcvqwer"; for ( char c : mychars.toCharArray() ) myMap.put(c, true); } public doo(String input) { StringBuilder output = new StringBuilder(); for ( char c : input.toCharArray() ) { if ( myMap.get(c) ) output.append(c); } } ... ... } I get a null pointer exception at the line if ( myMap.get(c) ) -- What am I doing wrong? 回答1

问题 When I try to run my application on Huawei P9 I’m getting the error Attempt to invoke virtual method 'int com.huawei.lcagent.client.LogCollectManager.getUserType()' on a null object reference Is there any way to debug this because application works on other Android 6 phones (Samsung, HTC...). APP: https://play.google.com/store/apps/details?id=com.morescreens.mkt LOG: 07-04 10:42:56.045: W/System.err(955): java.lang.NullPointerException: Attempt to invoke virtual method 'int com.huawei.lcagent

问题 I am writing an application for read the mifare card,but when I pass the APDU the error occur that on emulator "java.lang.nullpointerexception".I have successfully detect the ISO14443_CARD after that I pass the APDU like if (tp.hasTargetType(TargetType.ISO14443_CARD)){ form.append("Target is ISO14443_CARD\n"); try { static byte[] APDU_AUTH1 = { (byte) 0xff, (byte) 0x86, (byte) 0x00, (byte) 0x00, (byte) 0x05,(byte)0x01,(byte)0x00,(byte)0xfc,(byte)0x60,(byte)0x00}; static byte[] STATUS_BYTE = {

问题 First, I am an android rookie, so my solution ways can be found awkward, and i am open to suggestions. I am trying to create a game manager object that handles all transitions between activities. And my purpose is that while in an activity, menuOut method will call the changeActivity method of GameManager object with nextActivity argument and changeActivity will start that Activity. I am getting errors consistently, and did not find a solution. Here is my source codes: GameManager: public

问题 As the title says I have NPE error. It happens on line: while (getWidth() > bowl.getX()+10) { If I remove it, it shows it happens on next line: bowl.move(10.0, 0); I concluded that eclipse does not see my "bowl" initialized. Why? Doesn't "new GOval" deal with that? I've seen in one of the threads here that a solution was to split declaration and initialization to different lines, but I think it is unlikely to be a primary solution (besides, it didn't help in my case) Any suggestions on this