java convert string to long null safe

stackoverflow.com › questions › 49894638 › nullsafe-long-valueof

You can use the NumberUtils from Apache Commons. It's null-safe and you can optionally specify a default value.

Example:

NumberUtils.toLong(null) = 0L
NumberUtils.toLong("")   = 0L
NumberUtils.toLong("1")  = 1L

NumberUtils.toLong(null, 1L) = 1L
NumberUtils.toLong("", 1L)   = 1L
NumberUtils.toLong("1", 0L)  = 1L

For more info, check the API.

Answer from Ehler on Stack Overflow

Stack Overflow

stackoverflow.com › questions › 49894638 › nullsafe-long-valueof

parsing - Nullsafe Long valueOf - Stack Overflow

Top answer

1 of 5

You can use the NumberUtils from Apache Commons. It's null-safe and you can optionally specify a default value.

Example:

NumberUtils.toLong(null) = 0L
NumberUtils.toLong("")   = 0L
NumberUtils.toLong("1")  = 1L

NumberUtils.toLong(null, 1L) = 1L
NumberUtils.toLong("", 1L)   = 1L
NumberUtils.toLong("1", 0L)  = 1L

For more info, check the API.

2 of 5

When we say nullSafe we usually expect to receive a null from the API when passing null to it, not a 0 or -1 or any other value.

The intention is that the API does not break in case of receiving null, but simply returning null.

For this, use createLong static method of the org.apache.commons.lang3.math.NumberUtils.

CAUSION*: This throws NumberFormatException if the input String is NOT null and is NOT numeric.

CAUSION**: since 3.1 it handles hex (0Xhhhh) and octal (0ddd) notations. N.B. a leading zero means octal; spaces are not trimmed.

Sample:

NumberUtils.createLong(null) --> null
NumberUtils.createLong("1") --> 1
NumberUtils.createLong("hi") --> NumberFormatException
NumberUtils.createLong(" 11") --> NumberFormatException (does not trim)
NumberUtils.createLong("023") --> 19 (leading 0 means octal)
NumberUtils.createLong("0x23") --> 35 (leading 0x means hex)

LabEx

labex.io › tutorials › java-how-to-ensure-the-safety-and-robustness-of-long-to-string-conversion-in-java-414020

How to ensure the safety and robustness of long to string conversion in Java | LabEx

Test various scenarios, including null values, extreme values, and error conditions, to validate the correctness and reliability of your implementation. By following these best practices and recommendations, you can ensure the safety and robustness of long-to-string conversion in your Java applications, providing a reliable and user-friendly experience for your users.

BeginnersBook

beginnersbook.com › 2015 › 05 › java-long-to-string

Java long to String Conversion

Last Updated: November 20, 2022 ... · Using StringBuilder and StringBuffer · Note: Out of all these ways, the String.valueOf() is the preferred method for conversion as it is null safe....

Stack Overflow

stackoverflow.com › questions › 5522201 › any-simple-way-to-test-null-before-convert-an-object-to-string

java - Any simple way to test null before convert an object to string - Stack Overflow

Top answer

1 of 9

119

The static valueOf method in the String class will do the null check and return "null" if the object is null:

String stringRepresentation = String.valueOf(o);

2 of 9

Try Objects.toString(Object o, String nullDefault)

Example:

import java.util.Objects;

Object o1 = null;
Object o2 = "aString";
String s;

s = Objects.toString(o1, "isNull"); // returns "isNull"
s = Objects.toString(o2, "isNull"); // returns "aString"

Baeldung

baeldung.com › home › java › java string › convert long to string in java

Convert Long to String in Java | Baeldung

October 4, 2021 - Be careful because if obj is null, we’ll get an IllegalArgumentException. In summary, we’ve learned different ways to convert Long to String in Java.

Java67

java67.com › 2015 › 07 › how-to-parse-string-to-long-in-java.html

How to convert String to long in Java? Example | Java67

public Long(String s) throws NumberFormatException { this.value = parseLong(s, 10); } 3) The real method, parseLong() which does all the work of parsing throws NumberFormatException for invalid inputs e.g. null values, empty values, lonely plus or minus sign, alphanumeric String, and String with out of range long values. Here is a nice summary of different ways to convert String to Long object and long primitive in Java:

TutorialKart

tutorialkart.com › java › java-string-to-long

Convert String to Long in Java

January 9, 2023 - Exception in thread "main" java.lang.NumberFormatException: For input string: "5.354" at java.base/java.lang.NumberFormatException.forInputString(Unknown Source) at java.base/java.lang.Long.parseLong(Unknown Source) at java.base/java.lang.Long.parseLong(Unknown Source) at StringToLong.main(StringToLong.java:12) Also, if null is passed to Long.parseLong(), the function throws NullPointerException. ... /** * Java Program - Convert String to Long */ public class StringToLong { public static void main(String[] args) { //a string String str = null; //convert string to long long n = Long.parseLong(str); System.out.print(n); } }

Java2s

java2s.com › Code › Java › Class › NullSafeToString.htm

Null Safe To String : toString « Class « Java

Apache Commons

commons.apache.org › proper › commons-lang › javadocs › api-3.4 › index.html

Apache Commons Lang 3.4 API

JavaScript is disabled on your browser · Frame Alert · This document is designed to be viewed using the frames feature. If you see this message, you are using a non-frame-capable web client. Link to Non-frame version

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Verve AI

vervecopilot.com › interview-questions › why-is-mastering-java-long-to-string-essential-for-robust-java-development

Why Is Mastering Java Long To String Essential For Robust Java Development

They explicitly state the intention to convert the long to a String, making the code easier to read and understand for other developers. String.valueOf(Long obj) is also preferred for Long objects due to its null-safety.

GitHub

github.com › rapidsai › cudf › issues › 5110

[BUG] Cast from string to long should return null if string is not a valid long · Issue #5110 · rapidsai/cudf

January 3, 2020 - @Test void testCastStringToLongOverflow() { String outOfRangeLong = "9223372036854775808"; // Long.MAX_VALUE + 1 try (ColumnVector strings = ColumnVector.fromStrings(outOfRangeLong); ColumnVector cv = strings.castTo(DType.INT64); HostColumnVector longs = cv.copyToHost();) { assert(longs.isNull(0)); } }

Published May 06, 2020

Alvin Alexander

alvinalexander.com › java › edu › qanda › pjqa00011.shtml

How do I convert a String to a long with Java? | alvinalexander.com

public class StringToLong { public static void main (String[] args) { // String s = "fred"; // do this if you want an exception String s = "100"; try { long l = Long.parseLong(s.trim()); //<-- String to long here System.out.println("long l = " + l); } catch (NumberFormatException nfe) { System.out.println("NumberFormatException: " + nfe.getMessage()); } } } Note that I call trim() on the string I’m converting.

Tabnine

tabnine.com › home page › code › java › java.lang.long

java.lang.Long.parseLong java code examples | Tabnine

@Override public long contentLength() { try { return contentLength != null ? Long.parseLong(contentLength) : -1; } catch (NumberFormatException e) { return -1; } } ... private static long stringToLong(String s) { if (s == null) return -1; try { return Long.parseLong(s); } catch (NumberFormatException e) { return -1; } }

TheServerSide

theserverside.com › blog › Coffee-Talk-Java-News-Stories-and-Opinions › String-to-long-in-Java

String to long in Java

The correct way to convert a String to long in Java is with the parseLong method of the wrapper class. The constructor conversion approach is deprecated! Use parseLong instead.

Stack Overflow

stackoverflow.com › questions › 19977313 › java-string-to-long-conversion

Java String to Long Conversion - Stack Overflow

Top answer

1 of 7

I'm afraid the value is not 1454. The value is null, as evidenced by this line:

java.lang.NumberFormatException: null

You need to check your parameter name, and make sure you've got it right, including case and invisible characters.

2 of 7

java.lang.NumberFormatException: null

If String dxorderId is null then it will throw NumberFormatException

Solution

Check dxorderId is not null and not empty string

if(dxorderId != null && !dxorderId.equals(""))
{
  long orderid = Long.parseLong((dxorderId));
}

From oracle docs NumberFormatException

public class NumberFormatException
       extends IllegalArgumentException

Thrown to indicate that the application has attempted to convert a string to one of the numeric types, but that the string does not have the appropriate format.

Medium

medium.com › hackernoon › safely-tostring-a-java-object-a3d6ea3c404

Safely toString a Java object. Avoiding NPE | by Orléando Dassi | HackerNoon.com | Medium

December 31, 2023 - The printed string of our ObjectA into the console is: ObjectA{propA=’Fake propA’, objectB1=ObjectB{propB=’Fake propB’}, objectB2=null} More usages of the Objects class can be found on this page. To sum up, we have seen here a proper way to safely toString an object with embed properties.

TheServerSide

theserverside.com › blog › Coffee-Talk-Java-News-Stories-and-Opinions › long-to-String-in-Java

long to String in Java

The easiest way to convert a long to a String is to append it to double quote. However, for complex output where a long must be embedded in a Java String, use the printf or String.format method.

Stack Overflow

stackoverflow.com › questions › 7693324 › how-to-convert-string-to-long-in-java

How to convert String to long in Java? - Stack Overflow

Top answer

1 of 11

764

Use Long.parseLong()

Copy Long.parseLong("0", 10)        // returns 0L
 Long.parseLong("473", 10)      // returns 473L
 Long.parseLong("-0", 10)       // returns 0L
 Long.parseLong("-FF", 16)      // returns -255L
 Long.parseLong("1100110", 2)   // returns 102L
 Long.parseLong("99", 8)        // throws a NumberFormatException
 Long.parseLong("Hazelnut", 10) // throws a NumberFormatException
 Long.parseLong("Hazelnut", 36) // returns 1356099454469L
 Long.parseLong("999")          // returns 999L

2 of 11

156

To convert a String to a Long (object), use Long.valueOf(String s).longValue();

See link

Stack Overflow

stackoverflow.com › questions › 76514512 › null-safe-integer-longvalue-in-java

Null-safe Integer.longValue() in Java? - Stack Overflow

Especially when value is not just a value but is actually some function with long name and multiple arguments. Maybe I have missed something and there is such a method in any of the popular libraries? ... Java generally doesn't do "short and convenient". I recommend upgrading to Kotlin, which has null-safety built in: intValue?.toLong().

Stack Exchange

codereview.stackexchange.com › questions › 19773 › convert-string-to-integer-with-default-value

java - Convert String to Integer with default value - Code Review Stack Exchange

Top answer

1 of 7

here is a solution :

int tryParseInt(String value) { 
 try {  
     return Integer.parseInt(value);  
  } catch(NumberFormatException nfe) {  
      // Log exception.
      return 0;
  }  
}

you should catch NumberFormatException instead of exception.

2 of 7

I'd consider using NumberUtils.toInt from Apache Commons Lang which does exactly this:

public static int NumberUtils.toInt(java.lang.String str, int defaultValue)

The implementation uses the already mentioned Integer.parseInt with an additional null check.

See also: Effective Java, 2nd edition, Item 47: Know and use the libraries (The author mentions only the JDK's built-in libraries but I think the reasoning could be true for other libraries too.)