問題描述

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

這篇關于Integer.parseInt(String str) java.lang.NumberFormatException: 錯誤的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！