无法将字符串转换为整数。有时得到 NumberFormatException

Question

我正在尝试从 Facebook 帐户获取消息数、通知数和好友请求数。从 facebook 获取字符串数据后，我使用 Interger.parseInt(String) 方法将其转换为整数。根据我的代码逻辑，我将从 facebook 获取的数据放入 error、error1 和 error2 中，当它们是字符串时，在将它们转换为整数后，我将它们放入 actualfriend、actualmassage 和 actualnotification 中。最后我将实际数据与一些预期数据进行比较。

问题是我得到了正确的按摩计数结果，但是对于朋友请求和通知，我在 error1 和 error2 中得到了正确的数据，但是一旦我将它们从字符串中转换为整数，我得到了 actualfriend=0 和 actualnotification= 0.

 public  void operation() throws InterruptedException, AWTException ,StaleElementReferenceException,NoSuchElementException,NumberFormatException {
      int i=1;
      int j=1;
      while(i==1){
      String error = "1";
      String error1= "1";
      String error2= "1";
      System.out.println(error);
      if((error.length() != 0) && (error1.length() != 0) && (error2.length() != 0)){ 
      try{
       actualmassage = Integer.parseInt(error);
        }catch (NumberFormatException e) {
          error="5";
           try{ 
            actualnotification=Integer.parseInt(error1);
             }catch(NumberFormatException ee){
              error1="5";
               try{ 
                actualfriend=Integer.parseInt(error2);
                 }catch(NumberFormatException eee){
                   error2="5";
                 }//catch3
               }//catch2
           }//catch3
      }//if for massage 
      else if((error.length() !=0) && (error1.length() !=0) && (error2.length() !=0)){
          actualmassage = Integer.parseInt(error);
          actualnotification = Integer.parseInt(error1);
          actualfriend = Integer.parseInt(error2);
      }//else if
      else{

      }//else
      int expectedmassage =1;
      int expectednotification=0;
      int expectedfriend=0;
      if(expectedmassage == actualmassage ){
          Thread.sleep(4000);
          System.out.println("Readable Massage = "+error +" actualmassage = "+actualmassage);
      }else{
          System.outprintln("Does't Match");
          i++;
      }//else
      if(expectednotification == actualnotification){
          Thread.sleep(4000);
          System.out.println("Total Notification = "+error1 +" actualnotification = "+actualnotification);
      }else{
          System.outprintln("Does't Match");
          i++;
      }//else
      if(expectedfriend == actualfriend ){
          Thread.sleep(4000);
          System.out.println("Total FriendRequest = "+error2 +" actualfriend = "+actualfriend);
      }else{
          System.outprintln("Does't Match");
          i++;
      }//else

    //Counting number of runs
      System.out.println("Number of run = " + j);
      j++;
      }//while
      System.out.println("Stop");
      i=(i+2);  
 }//operation
public static void main(String[] args) throws StaleElementReferenceException, InterruptedException, AWTException,NoSuchElementException,NumberFormatException{
    fb c = new fb();
   }//main
  }//calss

Output for this-
1
Readable Massage = 1 actualmassage = 1
Total Notification = 1 actualnotification = 0
Total FriendRequest = 1 actualfriend = 0
Number of run = 1
1
Readable Massage = 1 actualmassage = 1
Total Notification = 1 actualnotification = 0
Total FriendRequest = 1 actualfriend = 0
Number of run = 2

如您所见，我正在获取- Readable Massage = 1（从错误变量获取）actualmassage = 1（在将其从字符串转换为整数后从 actualmassage 获取）。 Total Notification = 1（从 error1 变量获取）actualnotification = 0（在将它从字符串转换为整数后从 actualmassage 获取）这是错误的。 Total FriendRequest = 1（从 error2 变量获取）actualfriend = 0（将其从字符串转换为整数后从 actualfriend 获取）这是错误的。

将代码从-

更改为

      int expectedmassage =1;
      int expectednotification=0;
      int expectedfriend=0;
      if(expectedmassage == actualmassage ){
          Thread.sleep(4000);
          System.out.println("Readable Massage = "+error +" actualmassage = "+actualmassage);
      }else{
          System.out.print("Does't match");
          i++;
      }//else
      if(expectednotification == Integer.parseInt(error1)){
          Thread.sleep(4000);
          System.out.println("Total Notification = "+error1 +" actualnotification = "+actualnotification);
      }else{
          System.out.print("Does't match");
          i++;
      }//else
      if(expectedfriend == Integer.parseInt(error2)){
          Thread.sleep(4000);
          System.out.println("Total FriendRequest = "+error2 +" actualfriend = "+actualfriend);
      }else{
          System.out.print("Does't match");
          i++;
      }//else

但是在这样做之后我得到了-

 1
java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at com.selenium.fb.main1(fb.java:103)
at com.selenium.fb.main(fb.java:123)

Answer 1

看起来第一个 if(error.length() != 0) && (error1.length() != 0) && (error2.length() != 0) 是无法为 actualnotification 和 actualfriend 赋值，因为它没有到达 them.Change 具有以下代码的代码。我为每个创建了单独的 if 块并且它有效。

     try{
       actualmassage = Integer.parseInt(error);
        }catch (NumberFormatException e) {
          error="0";
        }//catch1
      }//if1
         if((error1.length() != 0)){
           try{ 
            actualnotification=Integer.parseInt(error1);
             }catch(NumberFormatException ee){
              error1="0";
               }//catch2
           }//if2   
        if((error2.length() != 0)){ 
              try{
                   actualfriend=Integer.parseInt(error2);
                 }catch(NumberFormatException eee){
                   error2="0";
                 }//catch3
                }//if3

无法将字符串转换为整数。有时得到 NumberFormatException

Not able to convert a string to integer. Sometime getting NumberFormatException

java

string

if-statement

exception

numberformatexception