numberformatexception

问题 I have a very big file which contains user ids like this. Each line in that big file is an user id. 149905320 1165665384 66969324 886633368 1145241312 286585320 1008665352 So in that big file, I will have around 30Million user id's. Now I am trying to select random user id's from that big file. Below is the program I have but at some point it always give me this exception like this- and I am not sure why this exception is happening. Exception in thread "main" java.lang.NumberFormatException:

问题 I am writing a program in Java where I got some textfields and a button. I get a java.lang.NumberFormatException: For input string: "" even though I have filled out all the textfields when running the program. My code looks something like this: button.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { method(); } } ); public void method() { try { String string1 = textfield1.getText(); String string2 = textfield2.getText(); String string3 =

问题 I wished to turn a string of single digit integers into an Integer ArrayList, and I'm getting a very odd exception. Here's the sample code: Scanner test = new Scanner(System.in); String[] temp = null; String line = null; ArrayList<Integer> artemp = new ArrayList<>(); while(test.hasNext()) { line = test.next(); temp = line.split(""); for(int i = 0; i < temp.length; i++) artemp.add(Integer.parseInt(temp[i])); for(int i : artemp) System.out.println(i); } It is basically supposed to read the

问题 I have an application which reads xls sheet using apache poi. When the cell has numeric value, i read it by row.getCell(i).getNumericValue(). But it returns floating point digit. like if the cell value is 1, it returns 1.0. Can i convert it to int ? Any helpwould be appreciated. I tried Integer.parseInt(value)- but it throws NumberFormat exception.Any help is appreciated.Here is the pseudo code: FileInputStream file = new FileInputStream(new File("C:\\test.xls")); HSSFWorkbook workbook = new

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . I am trying to convert a string to long and it throws the NumberFormatException . I don't think it is beyond range of long at all. Here is the code to convert, where count_strng is the String I want to convert to long. trim() function is not making any difference. long sum_link = Long.parseLong(count_strng.trim(

问题 I'm having a small error in my code that I can not for the life of me figure out. I have an array of strings that are representations of binary data (after converting them from hex) for example: one index is 1011 and another is 11100. I go through the array and pad each index with 0's so that each index is eight bytes. When I try to convert these representations into actual bytes I get an error when I try to parse '11111111' The error I get is: java.lang.NumberFormatException: Value out of

问题 I have a string arraylist with numbers like ["51,073","51,074","51,073"] now i want to convert this into a Double ArrayList and calculate the sum of the numbers in the array list. Here is the code : private ArrayList<String> totals = new ArrayList<>(); private ArrayList<Double> demototal = new ArrayList<>(); String total = itemData.getString(ParseBarcode.KEY_TOTAL); totals.add(total); /*converting all values from totals array to Double and add to arraylist demototal*/ for (int i = 0; i <

问题 import java.io.*; class AccountInfo { private String lastName; private String firstName; private int age; private float accountBalance; protected AccountInfo(final String last,final String first,final int ag,final float balance) throws IOException{ lastName=last; firstName=first; age=ag; accountBalance=balance; } public void saveState(final OutputStream stream){try{ OutputStreamWriter osw=new OutputStreamWriter(stream); BufferedWriter bw=new BufferedWriter(osw); bw.write(lastName); bw.newLine

问题 I have a String from which I would like to parse an integer and cannot find a way past this runtime exception. I understand that it is meant to display at times when a parseNUMBERTYPE function is applied to an inappropriately defined String, and that blank spaces or letters where the code expects numbers to be can trigger it. However, the String I am using as a test dummy is as far as I can tell simply the numeral 5. I have seen several suggestions in response to other users'

问题 Here i come up with problem while performing some operation like update,delete and insert but its return some null value with exception kindly some one could look at the code if its wrong: Error: HTTP Status 500 - null type Exception report message null description The server encountered an internal error that prevented it from fulfilling this request. exception java.lang.NumberFormatException: null java.lang.Integer.parseInt(Integer.java:454) java.lang.Integer.parseInt(Integer.java:527)