Integer.parseInt不会将String解析为int

Question

下面的代码来自一个试图从提交的html表单中读取数据的Servlet.变量fieldValue是一个String并打印正确的值(如此BizStr: 5)但是当我尝试将此值解析为整数时,它不会打印任何内容.

for(FileItem uploadItem : uploadItems){
  if(uploadItem.isFormField()){
    String fieldName = uploadItem.getFieldName();
    String fieldValue = uploadItem.getString();
    if(fieldName.equals("business_id")){
        out.println("BizStr: "+ fieldValue +"\n");
        out.println("BizInt: "+ Integer.parseInt(fieldValue )+"\n");
    }
  }
}

为什么这个字符串没有被解析为整数？

Answer 1

测试:

Integer.parseInt(" 5");  // space before; yields NumberFormatException

Integer.parseInt("5 ");  // space after; yields NumberFormatException

尝试trim()在fieldValue之前的解析:

out.println("BizInt: "+ Integer.parseInt(fieldValue.trim() )+"\n");