Develop Reference

Why am I getting StringIndexOutOfBoundsException error in this substring method?

protected Void doInBackground(Void... voids) {
...
ABV = elem.select("td > span.muted").text();
Log.d("myLOG_ABV", ABV);
Log.d("myLOG_ABVlength", String.valueOf(ABV.length()));
/*String temp_ABV = ABV.substring(ABV.length()-6, ABV.length());*/
... }
Result
D/myLOG_ABV: Russian River Brewing Company American Wild Ale | 7.50%
D/myLOG_ABVlength: 55
and then, I cancled the annotation code.
...
ABV = elem.select("td > span.muted").text();
Log.d("myLOG_ABV", ABV);
Log.d("myLOG_ABVlength", String.valueOf(ABV.length()));
***String temp_ABV = ABV.substring(ABV.length()-6, ABV.length());***
...
Result
Caused by: java.lang.StringIndexOutOfBoundsException: length=0;
index=-6
Why am I getting StringIndexOutOfBoundsException error in this substring method?
I got the result that 'ABVlength : 55' in my code with annotation.
But after cancellation of annotation, I got StringIndexOutOfBoundsException.
Seriously, I am fighting with this code for 7hours 30minutes.

So we have:
***String temp_ABV = ABV.substring(ABV.length()-6, ABV.length());***
Caused by: java.lang.StringIndexOutOfBoundsException: length=0; index=-6
How can you get an index of -6 in this situation? ABV must have zero length, i.e. "".
It may be the case that ABV should have at least six characters, but that indicates a bug elsewhere.
What to do?
First and foremost, validate your inputs.
Somewhere you would normally want something like:
if (abv.length() < 6) {
throw new IllegalArgumentException("...");
}
Next find where that value is coming from and fix the bug.
Looks like you're parsing some kind of external document. In this case you may want the handling to be more lenient:
int abvLen = abv.length();
int abvEndIndex = abvLen - 6;
if (abvEndIndex < 0) {
log.error("ABV length less than 6", abv);
abvEndIndex = 0;
}
String abvEnd = abv.substring(abvEndIndex, abvLen);

How to use a Cursor?

I have an app that receives the id of an animal and pass that id to a method from the database that will be read several times in a do-while. I want to know why this error happens?
This is my code:
bd = new BaseDados(getApplicationContext());
Cursor cc = bd.getIdAnimal(chipnumber);
if (cc.moveToFirst()) {
idanimal = cc.getInt(cc.getColumnIndex("idanimal"));
}
Cursor ccc = bd.getGruupsnosAnimals(idanimal);
do{
if(ccc.moveToFirst()){
String groupname= ccc.getString(ccc.getColumnIndex("groupname"));
}
}while (ccc.moveToNext());
This is my error:
Process: com.example.nobre.myapplication, PID: 4529
android.database.sqlite.SQLiteException: not an error (code 0)
at android.database.sqlite.SQLiteConnection.nativeExecuteForCursorWindow(Native Method)
at android.database.sqlite.SQLiteConnection.executeForCursorWindow(SQLiteConnection.java:845)
at android.database.sqlite.SQLiteSession.executeForCursorWindow(SQLiteSession.java:836)
at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:62)
at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:144)
at android.database.sqlite.SQLiteCursor.getCount(SQLiteCursor.java:133)
at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:197)
at android.database.AbstractCursor.moveToFirst(AbstractCursor.java:237)
at com.example.nobre.myapplication.Activities.VerAnimaisActivity.showDialog(VerAnimaisActivity.java:193)
at com.example.nobre.myapplication.Activities.VerAnimaisActivity$2.onClick(VerAnimaisActivity.java:153)
at android.view.View.performClick(View.java:4780)
at android.view.View$PerformClick.run(View.java:19866)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Exception: not an error? That's a new one.
Your bottom loop is a bit weird and may be a bug- you're moving to next but may not even have moved to first if that failed. And if it succeeded you'll infinitely loop. Try this instead:
if(ccc.moveToFirst()){
do{
String groupname= ccc.getString(ccc.getColumnIndex("groupname"));
}while (ccc.moveToNext());
}

do{
if(ccc.moveToFirst()){
String groupname= ccc.getString(ccc.getColumnIndex("groupname"));
}
}while (ccc.moveToNext());
this is an infinite loop, while you have next item in your cursor, you move to first one, and next iteration you would again move to first one.
Also do not forget to call Cursor.close() after usage.

Try this:
// Move the cursor to the first row if cursor is not empty
if(ccc.moveToFirst()) {
do{
String groupname= ccc.getString(ccc.getColumnIndex("groupname"));
}while (ccc.moveToNext()); // Move cursor to next row until it pass last entry
}
Instead of:
do{
if(ccc.moveToFirst()) {
String groupname= ccc.getString(ccc.getColumnIndex("groupname"));
}
}while (ccc.moveToNext());

Android Studio app keeps crashing after button click

Im a beginner in java but I'm trying to build exercises and I ran into this problem. The user types in a donation, presses the button and the value of donations increments. Ive written the entire code but when I click the button to add to the donation count, the app crashes. Ive followed all the teachings of my teacher. I create a method in the activity, the in the ui builder I go to the button on click property and set it to that method. It should go smoothly but it crashes whenever I click the button. This is my activity which I set the onClick property to computeDonation.
public void computeDonation(View v){
String addedText = ((EditText)findViewById(R.id.AmountText)).getText().toString();
DonationModel donation = new DonationModel(addedText);
String answer = donation.calcDonation();
((TextView)findViewById(R.id.totalText)).setText(answer);
}
This is the model:
String textAdded;
double addedDonation;
public DonationModel(String y) {
textAdded = y;
}
public String calcDonation(){
double counter = Double.parseDouble(textAdded);
addedDonation += counter;
Locale locale = new Locale("en", "CA");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
return fmt.format(addedDonation);
}
Ive even tried without the number format just to see if it sends back to the activity but it doesn't. BTW for my class I'm using an older version of android studio.
This is the logcat:
02-15 17:12:28.797 21619-21619/ca.roumani.donations E/AndroidRuntime: FATAL EXCEPTION: main
Process: ca.roumani.donations, PID: 21619
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5197)
at android.view.View$PerformClick.run(View.java:20909)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5942)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5197) 
at android.view.View$PerformClick.run(View.java:20909) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:145) 
at android.app.ActivityThread.main(ActivityThread.java:5942) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 
Caused by: java.lang.NumberFormatException: Invalid double: ""
at java.lang.StringToReal.invalidReal(StringToReal.java:63)
at java.lang.StringToReal.parseDouble(StringToReal.java:267)
at java.lang.Double.parseDouble(Double.java:301)
at ca.roumani.donations.DonationModel.calcDonation(DonationModel.java:20)
at ca.roumani.donations.DonationActivity.computeDonation(DonationActivity.java:24)
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
at android.view.View.performClick(View.java:5197) 
at android.view.View$PerformClick.run(View.java:20909) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:145) 
at android.app.ActivityThread.main(ActivityThread.java:5942) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 

It seems like your textAdded is an empty String, which causes the NumberFormatException and crashes your app. What you can do to prevent this, is to check if your textAdded is not empty before parsing it:
public String calcDonation() {
if (TextUtils.isEmpty(textAdded)) {
//textAdded is empty, so just return an empty String
return "";
}
//We're sure that textAdded has a value, so we can try to parse it
double counter = Double.parseDouble(textAdded);
addedDonation += counter;
Locale locale = new Locale("en", "CA");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
return fmt.format(addedDonation);
}
Or just prevent the method from being invoked before the user has entered a value in the EditText view:
public void computeDonation(View v){
String addedText = ((EditText)findViewById(R.id.AmountText)).getText().toString();
if (TextUtils.isEmpty(textAdded)) {
Toast.makeText(context, "Please enter a valid number", Toast.LENGTH_SHORT).show();
} else {
DonationModel donation = new DonationModel(addedText);
String answer = donation.calcDonation();
((TextView)findViewById(R.id.totalText)).setText(answer);
}
}

I don't see where double addedDonation; is initialized, you can't use += when the variable has no value.

The problem is that you attempt to parse an empty string as a double. You need to verify that the user entered valid data before doing any calculations. One way to help you do this is to separate the calculation from the String passing and formatting. I suggest that you modify calcDonation() so that it only handles numeric data. Another method can worry about converting numbers to and from Strings. This will allow you to validate user input and display an appropriate error message when necessary.

Selenium testing with lists for load performance

I'm attempting to use a unit test of mine for "load" testing on our browser. For various reasons, we have seen performance degradation on the browser side, because we heavily rely on the print dialog.
I have the following unit test working via ScalaTest:
class LoadPrePaidSpec extends FlatSpec with Matchers with Chrome with Eventually {
implicit override val patienceConfig =
PatienceConfig(timeout = scaled(Span(40, Seconds)), interval = scaled(Span(100, Millis)))
def build(csvLine:String):TestCSVHolder ={
val split = csvLine.split(",")
TestCSVHolder(memberId = split(0), preSaleCode = split(1),
prePaidCode = split(2), lastName = split(3), firstName = split(4), badgeName = split(5))
}
def memberHelper(member: TestCSVHolder): Unit = {
//insert member id via prepaid code
textField("member_id").value = member.prePaidCode
//fire keyup event
executeScript("var eventToFire=jQuery.Event(\"keyup\");eventToFire.keyCode=221;eventToFire.which=221;" +
"$(\"#member_id\").trigger(eventToFire)")
eventually {
val eles = webDriver.findElements(By.xpath(s"//*[contains(#id, '${member.memberId}')]"))
eles.get(0).getTagName
//We remove the head element because it just says Prep For Print
val tdEles = (eles.get(0).findElements(By.tagName("td")).toList.tail)
tdEles(0).getText() should be(member.lastName)
tdEles(1).getText() should be(member.firstName)
tdEles(2).getText() should be(member.badgeName)
}
}
"Scanning an ID" should "look up the member" in {
val member = new TestCSVHolder("100001", "ABCD", "[-100001-ABCD]", "John", "Doe", "JohnDoe")
go to (url)
//login
textField("user_name").value = "mrkaiser"
webDriver.findElementById("credentials").sendKeys("somepassword")
click on ("btnLogin")
//click to pre-paid
click on linkText("Pre-Paid")
memberHelper())
webDriver.quit()
}
}
However when I try to iterate through a list of elements using a foreach and passing in memberHelper, after a list of about 5 elements, I get the following stack trace:
The code passed to eventually never returned normally. Attempted 369 times over 40.110734904 seconds. Last failure message: Index: 0, Size: 0.
ScalaTestFailureLocation: LoadPrePaidSpec at (LoadPrePaidSpec.scala:43)
org.scalatest.exceptions.TestFailedDueToTimeoutException: The code passed to eventually never returned normally. Attempted 369 times over 40.110734904 seconds. Last failure message: Index: 0, Size: 0.
at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:420)
at org.scalatest.concurrent.Eventually$class.eventually(Eventually.scala:438)
at LoadPrePaidSpec.eventually(LoadPrePaidSpec.scala:17)
at LoadPrePaidSpec.memberHelper(LoadPrePaidSpec.scala:43)
at LoadPrePaidSpec$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(LoadPrePaidSpec.scala:70)
at LoadPrePaidSpec$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(LoadPrePaidSpec.scala:70)
at scala.collection.immutable.List.foreach(List.scala:383)
at LoadPrePaidSpec$$anonfun$1.apply$mcV$sp(LoadPrePaidSpec.scala:70)
at LoadPrePaidSpec$$anonfun$1.apply(LoadPrePaidSpec.scala:54)
at LoadPrePaidSpec$$anonfun$1.apply(LoadPrePaidSpec.scala:54)
at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.FlatSpecLike$$anon$1.apply(FlatSpecLike.scala:1647)
at org.scalatest.Suite$class.withFixture(Suite.scala:1122)
at org.scalatest.FlatSpec.withFixture(FlatSpec.scala:1683)
at org.scalatest.FlatSpecLike$class.invokeWithFixture$1(FlatSpecLike.scala:1644)
at org.scalatest.FlatSpecLike$$anonfun$runTest$1.apply(FlatSpecLike.scala:1656)
at org.scalatest.FlatSpecLike$$anonfun$runTest$1.apply(FlatSpecLike.scala:1656)
at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
at org.scalatest.FlatSpecLike$class.runTest(FlatSpecLike.scala:1656)
at org.scalatest.FlatSpec.runTest(FlatSpec.scala:1683)
at org.scalatest.FlatSpecLike$$anonfun$runTests$1.apply(FlatSpecLike.scala:1714)
at org.scalatest.FlatSpecLike$$anonfun$runTests$1.apply(FlatSpecLike.scala:1714)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:413)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:401)
at scala.collection.immutable.List.foreach(List.scala:383)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:390)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:427)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:401)
at scala.collection.immutable.List.foreach(List.scala:383)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:396)
at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:483)
at org.scalatest.FlatSpecLike$class.runTests(FlatSpecLike.scala:1714)
at org.scalatest.FlatSpec.runTests(FlatSpec.scala:1683)
at org.scalatest.Suite$class.run(Suite.scala:1424)
at org.scalatest.FlatSpec.org$scalatest$FlatSpecLike$$super$run(FlatSpec.scala:1683)
at org.scalatest.FlatSpecLike$$anonfun$run$1.apply(FlatSpecLike.scala:1760)
at org.scalatest.FlatSpecLike$$anonfun$run$1.apply(FlatSpecLike.scala:1760)
at org.scalatest.SuperEngine.runImpl(Engine.scala:545)
at org.scalatest.FlatSpecLike$class.run(FlatSpecLike.scala:1760)
at org.scalatest.FlatSpec.run(FlatSpec.scala:1683)
at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:55)
at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$3.apply(Runner.scala:2563)
at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$3.apply(Runner.scala:2557)
at scala.collection.immutable.List.foreach(List.scala:383)
at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:2557)
at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1044)
at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1043)
at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:2722)
at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:1043)
at org.scalatest.tools.Runner$.run(Runner.scala:883)
at org.scalatest.tools.Runner.run(Runner.scala)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.runScalaTest2(ScalaTestRunner.java:138)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.main(ScalaTestRunner.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
at java.util.ArrayList.rangeCheck(ArrayList.java:653)
at java.util.ArrayList.get(ArrayList.java:429)
at LoadPrePaidSpec$$anonfun$memberHelper$1.apply$mcV$sp(LoadPrePaidSpec.scala:45)
at LoadPrePaidSpec$$anonfun$memberHelper$1.apply(LoadPrePaidSpec.scala:43)
at LoadPrePaidSpec$$anonfun$memberHelper$1.apply(LoadPrePaidSpec.scala:43)
at org.scalatest.concurrent.Eventually$class.makeAValiantAttempt$1(Eventually.scala:394)
at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:408)
... 63 more
My end goal is to actually test something in the 20K range of elements from a file, but until I can get a small list like this working, I'm up a creek.
I'm using the chromedriver and am on Scala 2.11.6, scala test 2.2.0, selenium 2.35.0.

Remove extra dots in float value before a separater " , " occurs using java

I am generating a statistical calculator application.
So I want to format input from edittext like this
i/p = 3.5.6, 6.5 to 3.5 , 6.5
Using " , " (comma) as separator so splitting the input string to float array when a " , " occurs.
I want to ignore 3.5[.6] and generate array like this
s[1] = 3.5 , s[2] = 6.5
While calculating mean application crashes due to extra " . " dots.
s = it.getText().toString(); //"it" is edittext
s=s.replaceAll( ",+" , "," );
String[] strarray =s.split(",");
float[] farray = new float[strarray.length];
for(int i = 0; i < strarray.length; i++)
{
farray[i] = Float.parseFloat(strarray[i]);
}
--DEBUG LOGCAT--
W/dalvikvm(3051): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
FATAL EXCEPTION: main
java.lang.NumberFormatException: Invalid float: "6.7."
at java.lang.StringToReal.invalidReal(StringToReal.java:63)
at java.lang.StringToReal.parseFloat(StringToReal.java:310)
at java.lang.Float.parseFloat(Float.java:300)
at com.cal.mc2.Mean$1.onClick(Mean.java:67)
at android.view.View.performClick(View.java:4204)
at android.view.View$PerformClick.run(View.java:17355)
at android.os.Handler.handleCallback(Handler.java:725)`
`at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
Force finishing activity com.cal.mc2/.Mean

How about this simple function (IdeOne link here: https://ideone.com/utKPjP):
public static float myParseFloat(String str) {
int firstDot = str.indexOf('.');
if (firstDot != -1) {
int secondDot = str.indexOf('.', firstDot+1);
return Float.parseFloat(secondDot == -1 ? str : str.substring(0,secondDot));
}
return Float.parseFloat(str);
}
Then you just replace this statement in your code:
farray[i] = Float.parseFloat(strarray[i]);
with:
farray[i] = myParseFloat(strarray[i]);

You can use regex like this :
public static void main(String[] args) {
String s = "3.5.6, 6.5";
s = s.replaceAll("(?<=\\d\\.\\d)\\.\\d", "");// positive look behind. Only replace `.[digit]` if it is preceeded by [digit][.][digit]
System.out.println(s);
String[] arr = s.split(",");
System.out.println(Arrays.toString(arr));
}
O/P :
3.5, 6.5 --> value of s after replacement
[3.5, 6.5] --> array contents