【发布时间】：2019-12-15 12:50:28
【问题描述】：
如果我想从文本文件中读取文件并将其存储在一个数组中，每一行都会转到正确的数组 这是文本文件
111111,34,24.5,第一行
222222,53,22.0,第二行
333333,,32.0,第三行
44444,22,12.6,
如果由于异常说“缺少标题”或类似的东西，行是空的。 如果数组长度==4然后按顺序显示行但如果长度小于4并且行丢失抛出异常但是当我想放置最后一个数组[3]时会出现错误。看看你是否能看到对你有帮助的错误
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Itry {
public static void main(String[] args) {
// TODO Auto-generated method stub
String [] splitArray = new String[4];
String line = "";
String array1, description;
int number;
double price;
// Total sales
double total = 0;
Scanner keyboard = new Scanner (System.in);
// Allow the user to enter the name of text file that the data is stored in
System.out.println("This program will try to read data from a text file ");
System.out.print("Enter the file name: ");
String filename = keyboard.nextLine();
Scanner fileReader = null;
try {
File Fileobject = new File (filename);
fileReader = new Scanner (Fileobject);
System.out.println("\nTransactions");
System.out.println("================");
while(fileReader.hasNext())
{
// Contains stock code,Quantity,Price,Description
line = fileReader.nextLine();// Read a line of data from text file
splitArray = line.split(",");
// check to make sure there are 4 parts in splitArray
if(splitArray.length == 4)
{
// remove spaces
splitArray[0] = splitArray[0].trim();
splitArray[1] = splitArray[1].trim();
splitArray[2] = splitArray[2].trim();
splitArray[3] = splitArray[3].trim();
// Extract each item into an appropriate
// variable
try {
array1 = splitArray[0];
number = Integer.parseInt(splitArray[1]);
price = Double.parseDouble(splitArray[2]);
description = splitArray[3];
// Output item
System.out.println("Sold "+String.format("%-5d", number) +
String.format("%-12s", description )+ " at "+"£"+
String.format("%-5.2f", price));
// Compute total
total += number * price;
} // end of try
catch(NumberFormatException e)
{
System.out.println("Error: Cannot convert to number");
}
} //end of if
else if (splitArray[0].length()<1) {
try { splitArray[0] = splitArray[0].trim();
System.out.println(" Title is missing "+" "+splitArray[1] +""+splitArray[2]+"");
}
catch(NumberFormatException e)
{
System.out.println("Error: Cannot convert to number");
}
}
else if (splitArray[1].length()<=1) {
try { splitArray[1] = splitArray[1].trim();
System.out.println(splitArray[0]+" "+" here is missing " +""+splitArray[2] );
}
catch(NumberFormatException e)
{
System.out.println("Error: Cannot convert to number");
}}
else if (splitArray[2].length()<=1) {
try { splitArray[2] = splitArray[2].trim();
System.out.println(splitArray[0]+" "+splitArray[1] +""+" here is missing "+splitArray[3]);
}
catch(NumberFormatException e)
{
System.out.println("Error: Cannot convert to number");
}}
else if (splitArray[3].length()<=1) {
try { splitArray[3] = splitArray[3].trim();
System.out.println(splitArray[0]+" "+splitArray[1] +""+splitArray[2]+"title is missing");
}
catch(NumberFormatException e)
{
System.out.println("Error: Cannot convert to number");
}}
}//end of while
System.out.printf("\nTotal sales: £"+String.format("%-6.2f", total));
}// end of try block
catch (FileNotFoundException e)
{
System.out.println("Error - File does not exist");
}
}
}
【问题讨论】：
-
您对 splitarray[3] 的引用在 else off of if length 为 4，因此在您的最后一个示例行中，长度实际上是 3，并且引用 [3] 会给您一个错误。将 splitArray[3].length()= 4 && splitArray[3].length()
-
非常感谢，我现在就试试
-
@kila - 我希望解决方案对你有用。不要忘记接受答案，以便将来的访问者也可以放心地使用该解决方案。检查meta.stackexchange.com/questions/5234/… 了解如何操作。如有任何疑问/问题，请随时发表评论。
标签： java arrays file text is-empty