What is StringUtils.isAsciiPrintable in Java?

isAsciiPrintable() is a static method of the StringUtils class that is used to check if the given string contains only ASCII characters that are printable.

The method returns false if the input string is null.
The method returns true if the input string is empty.

What are ASCII printable characters?

ASCII printable characters are ASCII characters whose decimal value is in the range 32 to 127.

The following table lists all the printable ASCII characters with their decimal, hexadecimal, and octal values.

Character	Decimal Value	Hexadecimal Value	Octal Value
Space (" ")	32	20	040
!	33	21	041
"	34	22	042
#	35	23	043
$	36	24	044
%	37	25	045
&	38	26	046
’	39	27	047
(	40	28	050
)	41	29	051
*	42	2a	052
+	43	2b	053
,	44	2c	054
-	45	2d	055
.	46	2e	056
/	47	2f	057
0	48	30	060
1	49	31	061
2	50	32	062
3	51	33	063
4	52	34	064
5	53	35	065
6	54	36	066
7	55	37	067
8	56	38	070
9	57	39	071
:	58	3a	072
;	59	3b	073
<	60	3c	074
=	61	3d	075
>	62	3e	076
?	63	3f	077
@	64	40	100
A	65	41	101
B	66	42	102
C	67	43	103
D	68	44	104
E	69	45	105
F	70	46	106
G	71	47	107
H	72	48	110
I	73	49	111
J	74	4a	112
K	75	4b	113
L	76	4c	114
M	77	4d	115
N	78	4e	116
O	79	4f	117
P	80	50	120
Q	81	51	121
R	82	52	122
S	83	53	123
T	84	54	124
U	85	55	125
V	86	56	126
W	87	57	127
X	88	58	130
Y	89	59	131
Z	90	5a	132
[	91	5b	133
\	92	5c	134
]	93	5d	135
^	94	5e	136
_	95	5f	137
`	96	60	140
a	97	61	141
b	98	62	142
c	99	63	143
d	100	64	144
e	101	65	145
f	102	66	146
g	103	67	147
h	104	68	150
i	105	69	151
j	106	6a	152
k	107	6b	153
l	108	6c	154
m	109	6d	155
n	110	6e	156
o	111	6f	157
p	112	70	160
q	113	71	161
r	114	72	162
s	115	73	163
t	116	74	164
u	117	75	165
v	118	76	166
w	119	77	167
x	120	78	170
y	121	79	171
z	122	7a	172
{	123	7b	173
\|	124	7c	174
}	125	7d	175
~	126	7e	176

How to import `StringUtils`

StringUtils is defined in the Apache Commons Lang package. Apache Commons Lang can be added to the Maven project by adding the following dependency to the pom.xml file.

<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the StringUtils class as follows.

import org.apache.commons.lang3.StringUtils;

Syntax

public static boolean isAsciiPrintable(final CharSequence cs)

Parameters

final CharSequence cs: the character sequence/string to check.

Return value

This method returns true if all the characters in the string are in the range 32 to 126 else returns false.

Code


import org.apache.commons.lang3.StringUtils;
public class Main {
    public static void main(String[] args) {
        String s = "543234 asfg";
        System.out.printf("The output of StringUtils.isAsciiPrintable() for the string - '%s' is %s", s, StringUtils.isAsciiPrintable(s));
        System.out.println();
        s = "";
        System.out.printf("The output of StringUtils.isAsciiPrintable() for the string - '%s' is %s", s, StringUtils.isAsciiPrintable(s));
        System.out.println();
        s = null;
        System.out.printf("The output of StringUtils.isAsciiPrintable() for the string - '%s' is %s", s, StringUtils.isAsciiPrintable(s));
        System.out.println();
        s = "   ";
        System.out.printf("The output of StringUtils.isAsciiPrintable() for the string - '%s' is %s", s, StringUtils.isAsciiPrintable(s));
        System.out.println();
        s = "\u008f\u0045";
        System.out.printf("The output of StringUtils.isAsciiPrintable() for the string - '%s' is %s", s, StringUtils.isAsciiPrintable(s));
        System.out.println();
    }
}

Output

The output of the code will be as follows:

The output of StringUtils.isAsciiPrintable() for the string - '543234 asfg' is true
The output of StringUtils.isAsciiPrintable() for the string - '' is true
The output of StringUtils.isAsciiPrintable() for the string - 'null' is false
The output of StringUtils.isAsciiPrintable() for the string - '   ' is true
The output of StringUtils.isAsciiPrintable() for the string - 'E' is false

Explanation

Example 1

string - "543234 asfg"

The method returns true, as the string contains only ASCII printable characters.

Example 2

string - ""

The method returns true, as the string is empty.

Example 3

string - null

The method returns false, as the string points to null reference.

Example 4

string - " "

The method returns true, as the string contains only spaces and spaces are ASCII printable characters.

Example 5

string - "\u002f\u0045"

The method returns false, as the string contains Unicode characters that are non-ASCII printable characters.