Java lang instantiation exception

Java lang instantiation exception

Contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes (a string tokenizer, a random-number generator, and a bit array).

Provides a set of «lightweight» (all-Java language) components that, to the maximum degree possible, work the same on all platforms.

Uses of InstantiationException in java.lang

Uses of InstantiationException in java.lang.reflect

Uses the constructor represented by this Constructor object to create and initialize a new instance of the constructor’s declaring class, with the specified initialization parameters.

Uses of InstantiationException in java.util

Methods in java.util that throw InstantiationException

Modifier and Type	Method and Description
ResourceBundle	ResourceBundle.Control. newBundle (String baseName, Locale locale, String format, ClassLoader loader, boolean reload)

Instantiates a resource bundle for the given bundle name of the given format and locale, using the given class loader if necessary.

Uses of InstantiationException in javax.swing

Methods in javax.swing that throw InstantiationException

Modifier and Type	Method and Description
static void	UIManager. setLookAndFeel (String className)

Loads the LookAndFeel specified by the given class name, using the current thread’s context class loader, and passes it to setLookAndFeel(LookAndFeel) .

Uses of InstantiationException in org.w3c.dom.bootstrap

Methods in org.w3c.dom.bootstrap that throw InstantiationException

Modifier and Type	Method and Description
static DOMImplementationRegistry	DOMImplementationRegistry. newInstance ()

Uses of InstantiationException in org.xml.sax.helpers

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Instantiation Exception Class

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Thrown when an application tries to create an instance of a class using the newInstance method in class Class , but the specified class object cannot be instantiated.

[Android.Runtime.Register("java/lang/InstantiationException", DoNotGenerateAcw=true)] public class InstantiationException : Java.Lang.ReflectiveOperationException

[] type InstantiationException = class inherit ReflectiveOperationException

Remarks

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Constructs an InstantiationException with no detail message.

A constructor used when creating managed representations of JNI objects; called by the runtime.

Constructs an InstantiationException with the specified detail message.

Fields

Properties

Returns the cause of this throwable or null if the cause is nonexistent or unknown.

The handle to the underlying Android instance.

Creates a localized description of this throwable.

Returns the detail message string of this throwable.

This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

Methods

Appends the specified exception to the exceptions that were suppressed in order to deliver this exception.

Fills in the execution stack trace.

Provides programmatic access to the stack trace information printed by #printStackTrace() .

Returns an array containing all of the exceptions that were suppressed, typically by the try -with-resources statement, in order to deliver this exception.

Initializes the cause of this throwable to the specified value.

Prints this throwable and its backtrace to the standard error stream.

Prints this throwable and its backtrace to the specified print stream.

Prints this throwable and its backtrace to the specified print writer.

Sets the stack trace elements that will be returned by #getStackTrace() and printed by #printStackTrace() and related methods.

Explicit Interface Implementations

IJavaPeerable.Disposed()	(Inherited from Throwable)
IJavaPeerable.DisposeUnlessReferenced()	(Inherited from Throwable)
IJavaPeerable.Finalized()	(Inherited from Throwable)
IJavaPeerable.JniManagedPeerState	(Inherited from Throwable)
IJavaPeerable.SetJniIdentityHashCode(Int32)	(Inherited from Throwable)
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from Throwable)
IJavaPeerable.SetPeerReference(JniObjectReference)	(Inherited from Throwable)

Extension Methods

Performs an Android runtime-checked type conversion.

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Java lang instantiation exception

Use is subject to License Terms. Your use of this web site or any of its contents or software indicates your agreement to be bound by these License Terms.

Copyright © 2006 Sun Microsystems, Inc. and Motorola, Inc. All rights reserved.

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java.lang
Class InstantiationException

java.lang.Object  java.lang.Throwable  java.lang.Exception  java.lang.InstantiationException 

Thrown when an application tries to create an instance of a class using the newInstance method in class Class , but the specified class object cannot be instantiated because it is an interface or is an abstract class.

Since: JDK1.0, CLDC 1.0 See Also: Class.newInstance()

Constructor Summary

InstantiationException () Constructs an InstantiationException with no detail message.

InstantiationException (String s) Constructs an InstantiationException with the specified detail message.

Methods inherited from class java.lang.Throwable

getMessage, printStackTrace, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

InstantiationException

public InstantiationException()

InstantiationException

Parameters: s — the detail message.

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Copyright © 2006 Sun Microsystems, Inc. and Motorola, Inc. All rights reserved. Use is subject to License Terms. Your use of this web site or any of its content or software indicates your agreement to be bound by these License Terms.

For more information, please consult the JSR 118 specification.

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How to resolve a «java.lang.InstantiationException»?

I debugged this by the reason for the exception, ‘Thrown when an application tries to create an instance of a class using the newInstance method in class Class, but the specified class object cannot be instantiated because it is an interface or is an abstract class.’ I’m parsing in an XML file using SAX but when I call the class loader on the class, a is thrown.

How to resolve a «java.lang.InstantiationException»?

I’m parsing in an XML file using SAX but when I call the class loader on the class, a java.lang.InstantiationException is thrown.

I debugged this by the reason for the exception, ‘Thrown when an application tries to create an instance of a class using the newInstance method in class Class, but the specified class object cannot be instantiated because it is an interface or is an abstract class.’

But the location class isn’t an interface or abstract class. I’ve also checked that the class is in the correct package and it is.

Does anyone have any idea why the exception is being thrown in this case?

The exception is being thrown just after the first println in the startElement of the Parser class:

public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException < if (qName.equals("location"))< location = true; System.out.println("Found a location. "); //exception thrown after this statement as shown //in the error output below try < //Read in the values for the attributes of the element int locationID = Integer.parseInt(atts.getValue("id")); String locationName = atts.getValue("name"); //Generate a new instance of Location on-the-fly using reflection. The statement Class.forName("gmit.Location").newInstance(); invokes the //Java Class Loader and the calls the null (default) constructor of Location. Location loc = (Location) Class.forName("gmit.Location").newInstance(); loc.setId(locationID); //Now configure the Location object with an ID, Name, Description etc. loc.setName(locationName); > catch (Exception e) < e.printStackTrace(); >>else if (qName.equals("description"))< description = true; System.out.println("Found a description. You should tie this to the last location you encountered. "); >else if (qName.equals("exits"))< exits = true; System.out.println("Found an exit. You should tie this to the last location you encountered. "); >else if (qName.equals("item"))< item = true; System.out.println("Found an item. You should tie this to the last game-character you encountered if the boolean gameCharacter flag is true. "); >else if (qName.equals("game-character"))< gameCharacter = true; System.out.println("Found a game character. "); >else if (qName.equals("search-algorithm")) < searchAlgorithm = true; System.out.println("Found a search algo. You should tie this to the last game-character you encountered if the boolean gameCharacter flag is true. "); >> 

My complete location class:

The errors being thrown during run time:

Your Location class does not have a no-args constructor. (It has two constructors with declared arguments . so there is no default no-args constructor.)

• Add a no-args constructor.
• Reflectively lookup one of the Constructor objects on the Location Class object and invoke it using Constructor.newInstance(. ) with arguments that give the actual constructor argument values.

It looks like the first option is the better one in this context . ‘cos it looks like you don’t have the required argument values at that point in the code.

Java.lang.InstantiationException: java.lang.Class cannot, java.lang.InstantiationException: java.lang.Class cannot be instantiated at java.lang.Class.newInstance(Native Method) android. Share. …

Java InstantiationException

I made a class to implement an interface and was testing it using another class.

This is the class that I created.

public class MyWeaponI implements WeaponI < Random RAND = new Random(); private int maxDamage; private String name; public MyWeaponI(String name1)< maxDamage = 10; name = name1; >@Override public int getDamage() < return RAND.nextInt(maxDamage)+1; >@Override public int getMaxDamage() < return maxDamage; >@Override public String toString() < return String.format("Weapon %s, damage=%d", name, maxDamage); >@Override public void initFromString(String input) < Scanner s = new Scanner(input); s.useDelimiter("$n"); String pattern = "(\\w+)\\s*,\\s*(\\d)\\s*"; if(s.hasNext(pattern))< MatchResult m = s.match(); maxDamage = Integer.parseInt(m.group(2)); name = m.group(1); System.out.println(String.format("Weapon %s, damage=%d", m.group(1), Integer.parseInt(m.group(2)))); >> @Override public String getName() < return name; >> 

This is the part of the tester that I get the error in. I just took out part of the tester to reduce the amount of code that I was posting. If you need the full tester I can change it.

Class warriorClass = null, weaponClass = null, diskClass = null; for(int i=0;i assert weaponClass != null : "You need to supply a weapon class"; WeaponI weapon = (WeaponI)weaponClass.newInstance(); testWeapon(weapon); 

When I run the code, I get an InstatiationException on the line of the tester that starts with «WeaponI weapon» near the bottom. There are two other classes that that also need to be passed to the tester and I’m assuming that both of them will also have to same problem. I honestly have no idea how to fix the problem, so any help would be much appreciated.

Exception in thread "main" java.lang.InstantiationException: warriorsandweapons.MyWeaponI at java.lang.Class.newInstance(Class.java:368) at warriorsandweapons.Arena.main(Arena.java:308) Java Result: 1 

For Class.newInstance to work it needs a default constructor. You can add a default constructor to MyWeapon class and try.

Quoting from javadoc for Class

InstantiationException — if this Class represents an abstract class, an interface, an array class, a primitive type, or void; or if the class has no nullary constructor; or if the instantiation fails for some other reason.

You’re doing the following:

WeaponI weapon = (WeaponI)weaponClass.newInstance(); 

On class warriorsandweapons.MyWeaponI . This class has only one constructor, and it’s a constructor that takes a single argument.

If you look at the Javadoc for Class.newInstance() you see the following note:

The class is instantiated as if by a new expression with an empty argument list.

So you can only use newInstance if there is a constructor that doesn’t take arguments. There is no such constructor on MyWeaponI , that’s why you get this exception.

Instead, you can use java.lang.reflect.Constructor to create the instance and pass arguments:

Class weaponClass; // . Constructor constructor = weaponClass.getConstructor(String.class); WeaponI instance = constructor.newInstance(nameArgument); 

Android, java.lang.InstantiationException. I am making an app to send X amount of texts to people and after re-writing my code to include threads, it …

How to fix java.lang.InstantiationException?

I’m trying to export my database using FAB. This is the error

Everything was working until I inserted this codes:

FloatingActionButton fab1 = (FloatingActionButton) findViewById(R.id.fab1); fab1.setOnClickListener(new View.OnClickListener() < Intent sIntent = getIntent(); ExampleClass sClass = sIntent.getParcelableExtra("selected"); String selCode = sClass.getqCode(); @Override public void onClick(View v) < exportDataBaseIntoCSV(); >>); > public void exportDataBaseIntoCSV() < Intent sIntent = getIntent(); ExampleClass sClass = sIntent.getParcelableExtra("selected"); String selCode = sClass.getqCode(); ClassDB db = new ClassDB(context);//here CredentialDb is my database. you can create your db object. File exportDir = new File(Environment.getExternalStorageDirectory(), ""); if (!exportDir.exists()) < exportDir.mkdirs(); >File file = new File(exportDir, selCode +".csv"); try < file.createNewFile(); CSVWriter csvWrite = new CSVWriter(new FileWriter(file)); SQLiteDatabase sql_db = db.getReadableDatabase();//here create a method ,and return SQLiteDatabaseObject.getReadableDatabase(); Cursor curCSV = sql_db.rawQuery("SELECT * FROM "+selCode,null); csvWrite.writeNext(curCSV.getColumnNames()); while(curCSV.moveToNext()) < //Which column you want to export you can add over here. String arrStr[] =; csvWrite.writeNext(arrStr); > csvWrite.close(); curCSV.close(); > catch(Exception sqlEx) < Log.e("Error:", sqlEx.getMessage(), sqlEx); >> 

This is the first time that I see this error so I don’t have any idea how can I fix this.

It seems like the object cant get instantiated.Try adding a parameterized constructor in the class.

I think you should not write this code:

Intent sIntent = getIntent(); ExampleClass sClass = sIntent.getParcelableExtra("selected"); String selCode = sClass.getqCode(); 

Inside your new View.OnClickListener() anonymous class. It is not in any method, and is already written inside exportDataBaseIntoCSV() method.

Java.lang.InstantiationException android, 1. Remove this line, it’s useless and the cause of your problem. You can’t manually instantiate Services/Activities in Android, it forbids it and hence …

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