String isNullOrEmpty in Java?

Java Problem Overview

This surely has been asked before, but ~~Googling doesn't find it~~. Is there, in any of the standard java libraries (including apache/google/...), a static isNullOrEmpty() method for Strings?

Java Solutions

Solution 1 - Java

from Apache http://commons.apache.org/lang/">commons-lang</a>;.

The difference between empty and blank is : a string consisted of whitespaces only is blank but isn't empty.

I generally prefer using apache-commons if possible, instead of writing my own utility methods, although that is also plausible for simple ones like these.

Solution 2 - Java

If you are doing android development, you can use:

TextUtils.isEmpty (CharSequence str)

Added in API level 1 Returns true if the string is null or 0-length.

Solution 3 - Java

com.google.common.base.Strings.isNullOrEmpty(String string) from Google Guava

Solution 4 - Java

No, which is why so many other libraries have their own copy :)

Solution 5 - Java

You can add one

public static boolean isNullOrBlank(String param) { 
    return param == null || param.trim().length() == 0;
}

I have

public static boolean isSet(String param) { 
    // doesn't ignore spaces, but does save an object creation.
    return param != null && param.length() != 0; 
}

Solution 6 - Java

To check if a string got any characters, ie. not null or whitespaces, check StringUtils.hasText-method (if you are using Spring of course)

Example:

StringUtils.hasText(null) == false
StringUtils.hasText("") == false
StringUtils.hasText(" ") == false
StringUtils.hasText("12345") == true
StringUtils.hasText(" 12345 ") == true

Solution 7 - Java

In addition to the other answers, I ran across this because I'm a C# programmer primarily, but trying to keep fresh in Java. I noticed that when I tried to use StringUtils my IDE (Eclipse) imported it from com.mysql.jdbc.StringUtils which actually has an isNullOrEmpty(myStringObject) method.

ex.

import com.mysql.jdbc.StringUtils;

StringUtils.isNullOrEmpty(host)

Just another alternative for those who already have the MySQL connector referenced in your project, but not the other StringUtils library.

Solution 8 - Java

public static boolean isNull(String str) {
		return str == null ? true : false;
	}

	public static boolean isNullOrBlank(String param) {
		if (isNull(param) || param.trim().length() == 0) {
			return true;
		}
		return false;
	}

Solution 9 - Java

I've seen this method written a few times in projects I've been on but I have to say I've never written it myself, or called it either ... Generally I find null and empty are completely distinct conditions and I have no reason to ever conflate them.

Solution 10 - Java

For new projects, I've started having every class I write extend the same base class where I can put all the utility methods that are annoyingly missing from Java like this one, the equivalent for collections (tired of writing list != null && ! list.isEmpty()), null-safe equals, etc. I still use Apache Commons for the implementation but this saves a small amount of typing and I haven't seen any negative effects.

Content Type	Original Author	Original Content on Stackoverflow
Question	ripper234	View Question on Stackoverflow
Solution 1 - Java	Bozho	View Answer on Stackoverflow
Solution 2 - Java	Noah	View Answer on Stackoverflow
Solution 3 - Java	Jarek Przygódzki	View Answer on Stackoverflow
Solution 4 - Java	Jon Skeet	View Answer on Stackoverflow
Solution 5 - Java	Peter Lawrey	View Answer on Stackoverflow
Solution 6 - Java	Lamar	View Answer on Stackoverflow
Solution 7 - Java	Zack	View Answer on Stackoverflow
Solution 8 - Java	Vicky	View Answer on Stackoverflow
Solution 9 - Java	user207421	View Answer on Stackoverflow
Solution 10 - Java	Brian Deterling	View Answer on Stackoverflow