problem with 1.2.1 version - NullPointerException - Processing Forum

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gianluca_..

problem with 1.2.1 version - NullPointerException

in General Discussion • Other • 3 years ago

i got this generic error when start a sketch of our project:

Uncaught exception type:class java.lang.NullPointerException

java.lang.NullPointerException

at processing.app.antlr.PdeRecognizer.constructorCast(PdeRecognizer.java:1263)

at processing.app.antlr.PdeRecognizer.primaryExpression(PdeRecognizer.java:1568)

at processing.app.antlr.PdeRecognizer.postfixExpression(PdeRecognizer.java:7304)

at processing.app.antlr.PdeRecognizer.unaryExpressionNotPlusMinus(PdeRecognizer.java:7267)

at processing.app.antlr.PdeRecognizer.unaryExpression(PdeRecognizer.java:7125)

at processing.app.antlr.PdeRecognizer.multiplicativeExpression(PdeRecognizer.java:6988)

at processing.app.antlr.PdeRecognizer.additiveExpression(PdeRecognizer.java:6969)

at processing.app.antlr.PdeRecognizer.shiftExpression(PdeRecognizer.java:6882)

at processing.app.antlr.PdeRecognizer.relationalExpression(PdeRecognizer.java:6765)

at processing.app.antlr.PdeRecognizer.equalityExpression(PdeRecognizer.java:6716)

at processing.app.antlr.PdeRecognizer.andExpression(PdeRecognizer.java:6687)

at processing.app.antlr.PdeRecognizer.exclusiveOrExpression(PdeRecognizer.java:6658)

at processing.app.antlr.PdeRecognizer.inclusiveOrExpression(PdeRecognizer.java:6629)

at processing.app.antlr.PdeRecognizer.logicalAndExpression(PdeRecognizer.java:6600)

at processing.app.antlr.PdeRecognizer.logicalOrExpression(PdeRecognizer.java:6571)

at processing.app.antlr.PdeRecognizer.conditionalExpression(PdeRecognizer.java:4209)

at processing.app.antlr.PdeRecognizer.assignmentExpression(PdeRecognizer.java:1974)

at processing.app.antlr.PdeRecognizer.expression(PdeRecognizer.java:1302)

at processing.app.antlr.PdeRecognizer.expressionList(PdeRecognizer.java:6501)

at processing.app.antlr.PdeRecognizer.argList(PdeRecognizer.java:1414)

at processing.app.antlr.PdeRecognizer.identPrimary(PdeRecognizer.java:1741)

at processing.app.antlr.PdeRecognizer.primaryExpression(PdeRecognizer.java:1452)

at processing.app.antlr.PdeRecognizer.postfixExpression(PdeRecognizer.java:7304)

at processing.app.antlr.PdeRecognizer.unaryExpressionNotPlusMinus(PdeRecognizer.java:7267)

at processing.app.antlr.PdeRecognizer.unaryExpression(PdeRecognizer.java:7125)

at processing.app.antlr.PdeRecognizer.multiplicativeExpression(PdeRecognizer.java:6988)

at processing.app.antlr.PdeRecognizer.additiveExpression(PdeRecognizer.java:6939)

at processing.app.antlr.PdeRecognizer.shiftExpression(PdeRecognizer.java:6882)

at processing.app.antlr.PdeRecognizer.relationalExpression(PdeRecognizer.java:6765)

at processing.app.antlr.PdeRecognizer.equalityExpression(PdeRecognizer.java:6716)

at processing.app.antlr.PdeRecognizer.andExpression(PdeRecognizer.java:6687)

at processing.app.antlr.PdeRecognizer.exclusiveOrExpression(PdeRecognizer.java:6658)

at processing.app.antlr.PdeRecognizer.inclusiveOrExpression(PdeRecognizer.java:6629)

at processing.app.antlr.PdeRecognizer.logicalAndExpression(PdeRecognizer.java:6600)

at processing.app.antlr.PdeRecognizer.logicalOrExpression(PdeRecognizer.java:6571)

at processing.app.antlr.PdeRecognizer.conditionalExpression(PdeRecognizer.java:4209)

at processing.app.antlr.PdeRecognizer.assignmentExpression(PdeRecognizer.java:1974)

at processing.app.antlr.PdeRecognizer.expression(PdeRecognizer.java:1302)

at processing.app.antlr.PdeRecognizer.statement(PdeRecognizer.java:689)

at processing.app.antlr.PdeRecognizer.compoundStatement(PdeRecognizer.java:5608)

at processing.app.antlr.PdeRecognizer.classField(PdeRecognizer.java:2694)

at processing.app.antlr.PdeRecognizer.possiblyEmptyField(PdeRecognizer.java:345)

at processing.app.antlr.PdeRecognizer.activeProgram(PdeRecognizer.java:213)

at processing.app.antlr.PdeRecognizer.pdeProgram(PdeRecognizer.java:116)

at processing.app.preproc.PdePreprocessor.write(PdePreprocessor.java:453)

at processing.app.preproc.PdePreprocessor.write(PdePreprocessor.java:349)

at processing.app.Sketch.preprocess(Sketch.java:1254)

at processing.app.Sketch.preprocess(Sketch.java:1205)

at processing.app.Sketch.build(Sketch.java:1568)

at processing.app.Sketch.build(Sketch.java:1553)

at processing.app.Editor$DefaultRunHandler.run(Editor.java:1485)

at java.lang.Thread.run(Thread.java:619)

processing.app.debug.RunnerException: java.lang.NullPointerException

at processing.app.Sketch.preprocess(Sketch.java:1370)

at processing.app.Sketch.preprocess(Sketch.java:1205)

at processing.app.Sketch.build(Sketch.java:1568)

at processing.app.Sketch.build(Sketch.java:1553)

at processing.app.Editor$DefaultRunHandler.run(Editor.java:1485)

at java.lang.Thread.run(Thread.java:619)

there is no highlight code when i got this error..

i got no error using 1.1 version..

is this a bug?

2

Replies(6)

PhiLho

PhiLho

Re: problem with 1.2.1 version - NullPointerException

3 years ago

First thing: it is an error in Antlr, which is the tool used by Processing to transform its dialect of Java to pure Java.
So maybe it is a bug indeed, as it shouldn't crash but do meaningful error reporting if something is wrong in your code.

For your information, Processing 1.1 was still using the Java 1.4 syntax, while Processing 1.2.1 (and some intermediary versions before that) use the Java 1.5 syntax, allowing nice things like typed collections, for-each loop, etc.
So the problem might be in the definition of the new syntax.

I suggest you open a bug report ( Issues reporting) and attach your source code if it is not confidential.

rawray7

Re: problem with 1.2.1 version - NullPointerException

3 years ago

I'm getting this error as well after adding some code to a sketch which works fine on its own. (To clarify, both sketches work fine independently, but I receive this error when I add one to the other.) Any help?

PhiLho

PhiLho

Re: problem with 1.2.1 version - NullPointerException

3 years ago

Hard to give an advice without seeing some code. I suggest to check if everything is OK in your composite sketch: no duplicate setup() or draw(), no nested functions, matching number of opening and closing braces, etc.

den2themo..

Re: Re: problem with 1.2.1 version - NullPointerException

3 years ago

my code here:

String[] lines;

String[] lines_new;

int i = 0;

void setup() {
size(200, 200);
background(0);
stroke(255);
// frameRate(12);

lines = loadStrings("positions.txt");
noLoop();
}

void draw() {

for (i=0; i<lines.length; i++) {

   lines[i] = trim(lines[i]);

   lines_new[i] = lines[i];   ///error here
//   lines_new[i] = "huj"; /// the same shit...

     println(i+": "+lines[i]);

     }

}

ERROR:

processing.app.debug.RunnerException: NullPointerException
    at processing.app.Sketch.placeException(Sketch.java:1543)
    at processing.app.debug.Runner.findException(Runner.java:582)
    at processing.app.debug.Runner.reportException(Runner.java:558)
    at processing.app.debug.Runner.exception(Runner.java:498)
    at processing.app.debug.EventThread.exceptionEvent(EventThread.java:367)
    at processing.app.debug.EventThread.handleEvent(EventThread.java:255)
    at processing.app.debug.EventThread.run(EventThread.java:89)
Exception in thread "Animation Thread" java.lang.NullPointerException
    at CLDATA.draw(CLDATA.java:42)
    at processing.core.PApplet.handleDraw(Unknown Source)
    at processing.core.PApplet.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:619)

blindfish

blindfish

Re: problem with 1.2.1 version - NullPointerException

3 years ago

Seems like a perfectly valid error to me: You declare lines_new[] as an empty array and then try and reference non-existent elements when you copy values from the lines array. Try adding the following after the loadStrings operation in setup:

lines_new = new String[lines.length];

Maybe a change has occurred in the way arrays are handled?

PhiLho

PhiLho

Re: problem with 1.2.1 version - NullPointerException

3 years ago

It is nice you searched the forum before reporting an error. But for the record (and those coming here later), NullPointerExceptions (NPE in short) are a very common runtime error in Java (thus in Processing). The one of this thread is much more uncommon, as it is Processing itself which is failing, so it is unrelated to your problem.

An NPE happens when you try to call a method (or access a field) on an object which have not been initialized yet. Ie. when you do x.foo() or y = x.bar and x has not received a value (it is null, hence the name).

That's the case here. As blindfish pointed out, you declared lines_new but not initialized it (you must indicate what is its size, Java has no dynamic arrays - well, they are a different beast, called ArrayList).

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