I created a method and keep getting an error that I need to include a } at the end of my method. I put the } in and the error is still there! If I then delete that } the same error will pop up on a prior method; and that error wasn't there before. in other words, if i type the } on my most recent method then the error stays there and only there. if i delete it, it duplicates that error on my prior method.
private void putThreeBeepers() {
for (int i = 0; i < 2; i++) {
putBeeper();
move();
}
putBeeper();
}
private void backUp() {
turnAround();
move();
turnAround();
}
You really want to go to the top of your file and do proper and consistent indention all the way to the bottom.
For example...
private void putThreeBeepers()
{
for (int i = 0; i < 2; i++) {
putBeeper();
move();
}
putBeeper();
}
private void backUp()
{
turnAround();
move();
turnAround();
}
Odds are, somewhere along the line, you are missing a }. Your description isn't super clear, but if the code you posted is how you actually have it formatted in your file then odds are you just missed something somewhere... and poor indentation makes it very hard to spot.
The fact that the message is changing is confusing, but it is the sort of thing you see in these cases.
the error might be misleading. In my case i had incorrect/incomplete comment statements such as below which is broken lead to this error:
/*
// */
*/
Fixing the comments fixed the error. Hope this helps. Thanks.
I think this can be caused by a number of different problems. :(
In my case it was that I have forgotten to specify the type of two parameters in one of my methods declareations.
To fix I had to change this:
onUpgrade(SQLiteDatabase pDb, pOldVersion, pNewVersion)
{
}
to this:
onUpgrade(SQLiteDatabase pDb, int pOldVersion, int pNewVersion)
It might be due to invisible Chars when copying code from PDF ebook.
Be careful of the little red dot '.'
Choose 'Select First Character' -> then delete it.
Also, the same error might occur if you accidentally write an if-statement outside of a method. I kept overlooking it since I was looking at the bracket-matching only.
I just simply add another"}",makes as "}}",then problem solved
I didnt have to put anther "}" for my other java code exercise.
Im a java beginner,I've come across same problem so I searched online found this thread.Hope this help
Had the same problem. Turned out to be a very fundamental oversight.
I was having the properties of a class declared like this:
private Texture foo;
private Sprite bar;
foo = new Texture();
bar = new Sprite();
The mistake was i had been instantiating the foo and bar variables outside the functions
of the class. When I put the
foo = new Texture();
bar = new Sprite();
into their proper functions (like below), the error went away.
private Texture foo;
private Sprite bar;
// function
public void instantiateVariables(){
foo = new Texture();
bar = new Sprite();
}
I got this error due to a missing <%.
Here are the steps.
Just copy paste your code in notepad
Remove copy from Java file
Again copy notepad and paste into Java file.
An error will be gone.
This question have already accepted answer but still there are some other problems where it occurs (like even though all statements are there correctly sometimes we will get this issue) and there are solutions too.
Recently I came across like this situation in eclipse workspace.
The solution is
Take the back up of that java file.
Remove the java file from that location and do the build/compile
Paste the file in the same location and do the build/compile
If the above step 3 does not work create new file and paste the content/code from backup file and do the build/compile
If the above step 3&4 both are not working then type the code of that file manually end-to-end and do the build/compile
If this error comes in jsp, look for the braces. if open or close braces are missing, we will get this error.
Related
I am currently creating a plugin for Minecraft using the SpigotAPI. Reason I'm posting this here is because this I believe is a Java error. I am creating a duels plugin where inside my code it'll loop through an enum, and see if it's a specific type. The first time using it around it properly works, no problems. But when I try it for a second time without restarting my plugin/program/code it'll return the enum as null. Here is the code, is there a fix to this?
public DuelArenas[] getArenasWithType(DuelTypes type) {
String suffix = "_NORMAL";
List<DuelArenas> arenasAsList = new ArrayList<>();
switch (type) {
case NORMAL:
suffix = "_NORMAL";
break;
}
for (DuelArenas arena : duelArenaStatus.keySet()) {
if (arena.toString().endsWith(suffix)) {
arenasAsList.add(arena);
}
}
DuelArenas[] arenas = new DuelArenas[arenasAsList.size()];
return arenasAsList.toArray(arenas);
}
Stacktrace:
Caused by: java.lang.NullPointerException
at me.nick.acore.duels.DuelsAPI.getArenasWithType(DuelsAPI.java:97) ~[?:?]
And yes I've checked to see if the enum was null, and it was in fact null. Also line 97 is
if (arena.toString().endsWith(suffix)) {
And finally here is the DuelArena class
public enum DuelArenas {
ARENA_1_NORMAL, ARENA_2_NORMAL, ARENA_3_NORMAL, ARENA_4_NORMAL, ARENA_5_NORMAL,
ARENA_6_NORMAL, ARENA_7_NORMAL, ARENA_8_NORMAL, ARENA_9_NORMAL, ARENA_10_NORMAL,
ARENA_11_NORMAL, ARENA_12_NORMAL }
Thanks!
Your problem is that you cannot directly convert your custom DuelArenas class to a string. However when you are comparing to see if a .toString() ends with suffix, I feel that something is also going wrong. You would only ever use .toString to convert things like numbers to strings, and if your are converting a number to a string there is no way it will end in _NORMAL.
So if you want me to troubleshoot further please post your DuelArenas class, but until then my best guess is that when you do arena.toString you are looking to pull some sort of value from that class that is stored in it, and to do this you would do arena.variableInsideArenaName and work with that.
EDIT:
After seeing the class scratch that, the error in going to be somewhere in this line DuelArenas arena : duelArenaStatus.keySet()
I'm running into the strangest error in this program, which is confirmed when debugging it. I have the following code (boiled down to highlight the problem, of course):
BHFrame.java
public class BHFrame
{
private boolean uSS;
private StateSaver stateSaver;
public BHFrame(boolean useInternalStateSaver)
{
//Init code
uSS = useInternalStateSaver;
//More init code
System.out.println(uSS);
if (uSS)
{System.out.println("Entered 1");
stateSaver = new StateSaver(title, false);
stateSaver.addSaveable(getThis());
}
//More init code
System.out.println(uSS);
if (uSS)
{System.out.println("Entered 2");
try
{
stateSaver.loadState();
stateSaver.putState(getThis());
}
catch (IOException ex)
{
alertUserOfException(ex);
}
}
}
}
GUI.java
public class GUI extends BHFrame
{
public GUI(boolean useInternalStateSaver)
{
super(useInternalStateSaver);
}
}
Main.java
public class Main
{
public static void main(String[] args)
{
GUI gui = new GUI(false);
}
}
Output
false
false
Entered 2
Exception in thread "main" java.lang.NullPointerException
at bht.tools.comps.BHFrame.<init>(BHFrame.java:26)
at bhms.GUI.<init>(GUI.java:5)
at bhms.Main.main(Main.java:5)
The class BHFrame is extended and run from a child class that calls this constructor, but that really shouldn't affect this behavior. The problem is that, when false is passed to the constructor as useInternalStateSaver, the first if (uSS) is skipped, but the second is entered. Upon debugging, I found that uSS is false throughout runtime, including on the line of the second if statement, here. Why would Java enter an if statement when the condition returns false? Before you ask, I did delete the .class files and recompile it just in case there was some residual code messing with it, but I got the same result. And rest assured, all the references to the uSS variable are displayed here.
Solution
As it turns out, this appears to be a bug in NetBeans 7.1 Build 201109252201, wherein the IDE doesn't properly insert new code into the compiled .class files. The problem was fixed by compiling the files externally. A bug report has been submitted.
Whatever's throwing that exception is probably not in your posted code.
It's not being caught by your catch statement, which only catches IOException.
It's a NullPointerException and can occur anywhere.
You have shown no indication that the code inside your if block is actually executing. In your screenshot, there is absolutely know way of knowing if your if block is entered or not. There are no logging statements.
Add debugging messages at various points to see exactly what is happening. Or, you know, look at line 26 (wayyyyy before your posted code) to see why you're getting a NullPointerException.
I've seen crazy stuff like this when there is bad RAM on the machine. You might want to run memtest86.
You might also consider deleting all of your project class files, and then doing a build. Maybe you changed Main.java, but it was never recompiled. I hate that when that happens.
This is just a guess, because I can't see the code you are mentioning, but I reckon you have defined a local variable uSS in the second //More init code segment.
Once you define a local variable named the same as an instance variable, it 'hides' the instance variable. Better to qualify all instance variables with this.
So, try qualifying all above accesses of uSS with this. ... (this.uSS)
Even if this isn't the issue, it might be better to post the full code anyway.
HTH
I'm a new user of eclipse 3.7 and dont know why eclipse always auto adds "*/" when I didnt notice. So I'm wondering why this happened? I haven't catch when it happens since when I write the same pieces of the code the second time the problem disapears.Can someone tell me how to solve it?
for example,this following really annoys me
public void addBall()
{
try
{
Ball ball = new Ball();
comp.add(ball);
for (int i = 1; i <= STEPS; i++)
{
ball.move(comp.getBounds());
comp.paint(comp.getGraphics());
Thread.sleep(DELAY);
}
}
*/
catch (InterruptedException e)
{
}
}
The problem occurred when I press "{" following the word try. It seems only happens when the corresponding "}" is out of current view, however I'm not really sure.Plus,the compiler didnt give me any warnings.
I'd look at the Java code templates - possibly you triggered something there. The defined templates can be found in Preferences, the Java/Editor/Templates page.
At first look at the try template whether it contains the */; or look for similar patterns as well.
By default, Eclipse automatically adds "*/" when you input "/*" and hit Enter, the same way as it automatically adds closing parenthesis.
I'm reading the chapter 12 on the Combined Pattern in Head First Design Patterns.
On page 541,the sample DJView,it cant't run correctly in my computer.when i press the 'start', the program only sounds once rather than circularly .
i'm not sure whether because of the environment of my system.
but if i add one line code in the method meta of the class BeatModel,it works.like:
public void meta(MetaMessage message) {
if (message.getType() == 47) {
beatEvent();
sequencer.setMicrosecondPosition(0); //add this line
sequencer.start();
setBPM(getBPM());
}
}
can anyone tell me why? i'm so confused,is something wrong with the code given by the book or some other reason? help me .
Thanks in advance!!
So sorry,the code is long so i could not put all here，you could download from the offical website,here is the link http://www.headfirstlabs.com/books/hfdp/HeadFirstDesignPatterns_code102507.zip
you can find the sample in this folder '\HeadFirstDesignPatterns_code102507\HF_DP\src\headfirst\combined\djview'.
run the class DJTestDrive.java
Look forward to your help.
EDIT #2: For completeness' sake, the author of Head First Design Patterns Elisabeth Freeman herself has made a note of the fact that the code in her book has only been tested with Java 1.4. She has promised to take our feedback into account.
EDIT: There seems to be a bug with the Sequencer.setTempoInBPM during play. Your approach with setting the microsecond position to 0 is the right approach -- it basically rewinds the sequencer as soon as it ends (i.e. message type = 47).
Unfortunately, the sample code seems incorrect. There are several problems:
The sequencer is not initialized to play in a loop
The meta() method resets the BPM and renotifies all listeners, but does not reset the sequencer to its original position, which you did to get it to work. However, this method does not need to do anything so long as the sequencer is set to play in a loop.
The off() method sets the BPM to 0, which will fast forwards the sequencer to the end of all loops -- which means next time you start the player, it will start from the end and will play nothing.
These change should do the trick:
#1 In method BeatModel.buildTrackAndStart, add sequencer.setLoopCount as follows:
public void buildTrackAndStart() {
// ...
try {
sequencer.setSequence(sequence);
sequencer.setLoopCount(Integer.MAX_VALUE); // play forever
} catch(Exception e) {
// ...
}
#2 Remove all statements from method BeatModel.meta(MetaMessage):
public void meta(MetaMessage message) {
}
#3 Remove setBPM(0) from method BeatModel.off():
public void off() {
// -- remove this -- setBPM(0);
sequencer.stop();
}
On Java 8 just adding the
sequencer.setMicrosecondPosition(0);
to the BeatModel.meta() makes it work just fine!
Greetings to all,
hebgeenbrug
I meet the similar error when reading. in my computer the processBar doesn`t update.
1.First I add "sequencer.setMicrosecondPosition(0);" in "public void meta(MetaMessage message)" ;
2.Second I delete "sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);" in "public void setUpMidi()"; it continuous sound but "meta(MetaMessage message)" will not be notice,so ProcessBar not update.
3.Then it works
may be my experience can help others.
I have an Java class with a static final method getAll:
public static final Vector<Category> getAll(Context context, ContentValues where) {
ArrayList<Integer> IDs = null;
if(where != null && where.containsKey(DatabaseAdapter.KEY_PRODUCT)) {
IDs = OvertureItem.getAll(context, DatabaseAdapter.TABLE_PRODUCT_CATEGORY, new String[] { DatabaseAdapter.KEY_CATEGORY }, where);
} else {
IDs = OvertureItem.getAll(context, DatabaseAdapter.TABLE_CATEGORIES, where);
}
Vector<Category> categories = new Vector<Category>();
for(Integer id: IDs) {
categories.add(Category.get(context, id));
}
return categories;
}
Now I want to hand in null as a value for the where statemant so that it will just be ignored later on in the code. Anyway in the testcase for this method I have:
Vector<Category> categories = Category.getAll(context, null);
Which then in turn gives me a NoSuchMethodError. I don't know exactly why it does that. The only thing I could imagine is that the null I hand in would not match the signature of the above method. But how can I overcome this? I already thought of overloading. But this would just end in rewriting most of the code. At least when I do it, how I think.
Any suggestions on that?
Phil
P.S. This is the stack trace I get:
java.lang.NoSuchMethodError: com.sap.catalogue.model.Category.getAll
at com.sap.overture.test.model.CategoryTest.testGetAll(CategoryTest.java:59)
at java.lang.reflect.Method.invokeNative(Native Method)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:169)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:154)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:430)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1447)
If the method did not exist at compile-time, then the code would not compile.
If you get NoSuchMethodError at run-time, then this suggests that the version of the Category class you are running against is different than the version of the Category class you are compiling against.
What is your setup like - is this class in the same project? Are you copying in JARs from another project?
The real answer
So I now finally figured it out and it wasn't as obvious as I expected. I started wondering, when every new test case for any new method I wrote would give me the NoSuchMethodError. So I digged a little bit deeper and then, suddenly it came to my mind: "I changed the package name of the android application". I thought this would not make any difference to the test project as long as I kept the properties right in the AndroidManifest.xml but I was wrong!
In fact when your application package is named com.foo.bar.app, the package for your tests has to be named com.foo.bar.app.test! What happened was, that with my old configuration somehow the classes that sat in the bin/ folder were used. I thought, that they should have been deleted when I cleaned the project but they weren't. This way all of the older test cases would still pass and only the new ones would give me the NoSuchMethodError. After I deleted the bin/ folder manually I got a whole bunch of errors. I then renamed the package holding the test cases and did a full clean/ rebuild on the project et voilá everything is back to normal again.
Thanks for all the tips! I really appreciate your help that just kept me digging to the bottom of the problem. Hope this here will help anybody with the same problem in the future.
Phil