Integer.parseInt(String str) java.lang.NumberFormatException

问题描述

I keep getting number format expectations, even though I'm trimming the strings and they don't contain non numerical characters bizarrely it works for some numbers and not others. Below is an example of a string I get number format exception for. Also, any string starting with 0 e.g "0208405223", is returned 208405223, there's no zero anymore is that supposed to happen?

String n="3020857508";
Integer a = Integer.parseInt(n.trim());
System.out.println(a);

This is the exception:

Exception in thread "main" java.lang.NumberFormatException: For input string: "3020857508"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:583)
    at java.lang.Integer.parseInt(Integer.java:615)
    at JavaBeans.Main.main(Main.java:15)

It's because 3020857508 exceeds Integer.MAX_VALUE. You should use long to convert the string to number.

java> String n="3020857508";
//=> java.lang.String n = "3020857508"
java> Integer a = Integer.parseInt(n.trim());
//=> java.lang.NumberFormatException: For input string: "3020857508"
java> Integer.MAX_VALUE
//=> java.lang.Integer res2 = 2147483647
java> Long a = Long.parseLong(n.trim());
//=>java.lang.Long a = 3020857508

The above is javarepl output.

If you are using JDK9 or above, you can see the same result in jshell.

jshell> String n="3020857508"
n ==> "3020857508"

jshell> Integer a = Integer.parseInt(n.trim())
|  Exception java.lang.NumberFormatException: For input string: "3020857508"
|        at NumberFormatException.forInputString (NumberFormatException.java:65)
|        at Integer.parseInt (Integer.java:652)
|        at Integer.parseInt (Integer.java:770)
|        at (#2:1)

jshell> Integer.MAX_VALUE
$3 ==> 2147483647

jshell> Long a = Long.parseLong(n.trim());
a ==> 3020857508

这篇关于Integer.parseInt(String str) java.lang.NumberFormatException: 错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！