Exception in Thread "Main" Edu.stanford.nlp.io.runtimeioexception: Couldn't Read Tokensregexner

Table Of Contents

• Quick Video Fix
• What is the Exception in thread chief coffee.lang.nullpointerexception Error?
• How to Fix the Exception in thread master coffee.lang.nullpointerexception java Fault
  • 1st Gear up: Hash Tables
    • Video Overview: Data Structures: Hash Tables
  • 2nd Fix: Cryptography Extension Update
    • Video Overview: Java Cryptography Architecture (JCA)
  • 3rd Gear up: Statement Method
• Forum Feedback
• Conclusion
  • Related Posts:

In this post, nosotros provide three fixes For The "exception in thread "main" java.lang.nullpointerexception" fault.

As you tin see, over on Twitter lots of people experience this frustrating fault:

Exception in thread "principal" java.lang.NullPointerException
[error] at org.apache.spark.rdd.RDD.<init>(RDD.scala:79)

Today'southward a bad day :/

— Mario Pastorelli (@mapastr) Dec 1, 2015

JVM: Exception in thread "chief" coffee.lang.NullPointerException
ME: Ah, no

— i stan birds 🎵🎷🐓 (@_ardeej) Nov seven, 2015

cat ~/.bash_aliases
alias java = repeat "Exception in thread "primary" java.lang.NullPointerException."

— Жизнь Убогая (@grepdev) February iv, 2016

The exception in thread "main"java.lang.nullpointerexception mistake is probably the first exception y'all volition encounter when using java. It is challenging to solve since the name has a pointer, even so Java does non support pointers such as multiple inheritances.

In this article, we include a comprehensive guide on what the error is and how you can set up information technology. In Java, a nix value is allocated to an object as reference. Information technology shows that the object is pointing to a slice of data that is unknown.

Any NullPointerExceptions error means that you are pointing to something non-existent. For case, it is like searching for a five^thursday spot when in that location are merely four spots. Information technology comes nigh when you fail to fill your array of types. Therefore, information technology happens when the reference does not indicate to whatever location.

Declining to provide value to every index of your assortment volition crusade coffee to assign the array with default values. Java will give each assortment a default value – null. That is how a nullPointerExceptions comes about since Java does not let cipher.

While information technology is a real nightmare for beginners, it is an mistake that is quite easy to solve. Before discussing various ways to address the fault, it is essential to understand what information technology is, why the error comes well-nigh, and how to avoid it.

Quick Video Fix

What is the Exception in thread main java.lang.nullpointerexception Error?

The exception in thread "main"java.lang.nullpointerexception fault is an error or an exception which comes about when you endeavor to conduct an functioning with an object that has a null value.  The "main" part means that the exception is in the primary thread.

Since information technology is a runtime exception, don't expect to detect a NullPointerException in a program. Being a runtime exception implies that the plan ends at the runtime instead of at the compile time.

The error occurs when:

• You lot telephone call on an case method on any null object
• Calling the length of an array if the array is null
• Y'all access or change any variable on a null object
• You throw a zilch when an exception is expecting to throw
• Changing or accessing slots of null like to an array
• Trying to synchronize a zilch object or when you use nix in a synchronized java block

Like nosotros have mentioned earlier, null is a unique value that Java uses. It is essential when coding using some design patterns such every bit the Singleton pattern or Zip Object pattern. That is why nosotros need a zilch value.

A naught object pattern acts equally a surrogate for a missing object in a particular type; while the singleton pattern makes sure an instance of a class is created in one case. For example, declaring constructors to be private, and later forming a public method which returns a unique example of the entire type.

How to Ready the Exception in thread principal java.lang.nullpointerexception coffee Error

To successfully solve a NullPointerException error in Java, you first need to identify the cause. It is quite easy to know the cause of the error. But check the stack-trace of the exception. The stack-case will bear witness you the verbal line where the NPE has occurred.

Now, go to the line with the error and cheque for possible object operations. For example, check an accessing field, throwing an exception, or calling methods. These will requite you a hint on the naught object.

After identifying the cypher object, nosotros are halfway done. Understand why the object is invalid, and use the fixes below to solve the exception. Notation that the second part of identifying the error may vary. The null may be from a manufactory or a thread.

Since there are unlike causes of the thread "main"java.lang.nullpointerexception, we cannot narrow down to one solution. However, these different fixes will help you avoid the fault:

1st Fix: Hash Tables

Check your coding practice. If yous are coding using a "Hash Tabular array" course, a user from DevShed forums recommends the following:

1. Instead of using HashTable, information technology's improve to use HashMap since the former is actually quondam.
2. Use a file with "Properties file format."

Video Overview: Information Structures: Hash Tables

second Fix: Cryptography Extension Update

Co-ordinate to Symantec, if you encounter the problem when trying to run Coffee LiveUpdate ConfigEditor, information technology could be that the JCE- Java Cryptography Extension files need to be updated, or that the LiveUpdate Configuration file is unreadable. You can fix this by following these steps:

1. Update your JCE policy files
2. Delete LiveUpdate.conf files and then create a new 1
3. Alternatively, you tin also correct the Coffee Path

Note that this fix is only applicable to Windows 2003 and 2008.

Video Overview: Java Cryptography Compages (JCA)

3rd Ready: Argument Method

Coffee Code Geeks recommend checking the argument of a method. Before performing the body of a method, information technology is essential to check the statement of the process for any zilch values. Merely continue with the execution after making sure at that place aren't any goose egg values.

Alternatively, yous can send an "IllegalArguementException" and let the calling method know that something is incorrect with previously passed arguments.

For instance:

public static int getLength(String southward) {

if (s == aught)

throw new IllegalArguementException ("The argument cannot be null");

render s. length ( ) ;

}

Forum Feedback

To discover more about the Exception in thread "main" java.lang.NullPointerException error and what troubles people accept with it, we search through Java boards and forums. In full general, users were interested in Exception in thread "chief" coffee.lang.NullPointerException in Coffee, Selenium Eclipse, and Glassfish. They also wanted to know about Exception in thread chief java.lang.NullPointrException at java.io.file. init (unknown source).

A computer user shared that he had been stuck for hours trying to solve the fault message "Exception in thread "master" java.lang.NullPointerException" and that he was at his wit'south ends. He asked fellow JavaScript forum fellow member for advice, and they said that he had made a common JavaScript mistake. They explained that he had a variable with a null value somewhere in his code and every bit a effect, his method was throwing the NullPointerException.

Another forum affiche remarks that you should learn to read your stack trace if yous want to be able to notice and set up your lawmaking mistakes. He points out that after Exception in thread "main" coffee.lang.NullPointerException, you will come across java: (line number), which indicates in which line you should expect for the error. Then you should get over that line and find the variable, which is null and fix it in the lawmaking.

A poster explains that NullPointerException occurs when you declare an object reference, but practise not create the object. For case, if you lot create an assortment of a list, it doesn't create the objects in the list. In other words, when you get NullPointerException, you lot're trying to point something to something that has a null value and therefore, doesn't exist. The individual reminds that you can't phone call a method on null in JavaScript and that it's of import not to code around the error.

A person stated that if you have problems with NullPointerException you might want to start checking whether your variables are null earlier calling them.

• He mentioned that you could apply @Nullable and @NotNull annotations.
• The user explains that @Nullable remind you that you have to cheque for NullPointerExpceptions when you lot call a method that could return a nil value and when you're differencing values that could be nix. On the other hand, @NotNull declares that a method shouldn't be null and that a variable cannot take a nothing value.
• The user pointed out that you have to retrieve about ii phases if y'all want to use an object.
• First, you have to declare it, then you accept to initialize information technology.
• If you do non initialize an object, then y'all'll get the mistake Exception in thread "primary" java.lang.NullPointerException.
• The poster recommends that when you're in uncertainty to utilize print to see what's inside your variable.

A forum user shared that the code he had written was throwing the error Exception in thread "main" java.lang.NullPointerException.

• He had checked his variable, and it wasn't zippo, then he wasn't sure how to proceed.
• When he got in touch with other JavaScript users, they pointed out that he had a trouble with his manager array because he had forgotten to gear up 1 element in the array.
• As a result, 1 of his elements was null, which was triggering the NullPointerException.

Another Coffee expert says that in Java you don't work with an array of objects. Instead, you deal with arrays of references to objects, and that's why your references must point to an object before you telephone call a method.

• He explains that NullPointerException is a Runtime Exception, a programmatic error. The poster points out that you tin can assign a goose egg value to a reference, but you tin't employ such a reference.
• He also remarks that you might go the NullPointerException if you're trying to access or change a variable with a null value.

A person observed that dealing with Aught Pointers is easier if you employ Java eight or in a higher place because yous can use Optional. It's a new course in Coffee, which encapsulated an optional value and helps you lot avoid NullPointerExceptions birthday. On the other manus, some Coffee users are against using the Optional grade considering it doesn't make your code more than correct and they advise that yous rely on the regular methods in Java to check for a null value.

A person too comments that you'll get Exception in thread "main" java.lang.NullPointerException if you're attempting to throw cipher equally if it were a Throwable value or when y'all try to access/modify slots of nulls as if you lot're trying to access/modify an array.

Decision

Recall that whatsoever NullPointerException comes about when you employ a method on a variable which has not been initialized. Therefore, y'all tin can avert the mistake past always setting a default value for every variable.

Other ways to avoid exception in thread primary coffee.lang.nullpointerexception include using String.valueOf () method as opposed to toString () method. For example, if an application code needs a string representation, utilise the static method instead of the toString method which throws an NPE.

Consider using the ternary operator which is in the form of Boolean expression vii value1: value2. Alternatively, you lot can avoid the fault by creating methods which return to an empty collection, rather than those which return to null. Lastly, use Apache`due south StringUtils class. Apache is a library which provides utilities for APU; for case, cord manipulation methods.

At present that we have discussed what the mistake is, how it comes near, remedies to fix, and how to avoid it, you are in a better position to enjoy coding using Coffee.

Ryan is a reckoner enthusiast who has a knack for fixing difficult and technical software bug. Whether you're having bug with Windows, Safari, Chrome or even an HP printer, Ryan helps out by figuring out easy solutions to common error codes.

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Source: https://errorcodespro.com/exception-in-thread-main-java-lang-nullpointerexception/

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