1

I have a code which reads data from a file and inserts it into database.

this code writes the data into a file. 

public void save(Collection<Book> b) {
    try (PrintWriter print = new PrintWriter(this.file);) {
        for (Book book : b) {
            String str = book.getName() + "," + book.getAuthor() + ","
                    + book.getDate() + "\n";
            print.println(str);
        }
    } catch (Exception e) {
    }

}

this code writes the data from the a file and inserts it into db.

try(Reader reader = new FileReader(this.file);
            BufferedReader br = new BufferedReader(reader)) {
        connection = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/myBook", this.userName,
                this.pass);

        Statement statement = connection.createStatement();
        String str;          
        while((str = br.readLine()) != null){

            String[] array = str.split(",");
            statement.executeUpdate("Insert Into myBook.book (name,author,pubDate) values('"+array[0]+"', '"+ array[1]+"', '"+array[2]+"')");
        }

    }

But it throws Exception 

java.lang.ArrayIndexOutOfBoundsException

What is wrong?

Improve this question
12
  • because array has only one element Commented Apr 1, 2015 at 14:05
  • The input doesn't contain ",". It should have two or more to be able to use array[1] and array[2]. Commented Apr 1, 2015 at 14:06
  • no it contains definitely thees are my rows in the file Chenty,Rafi,01.25.1850 Kaytser,Rafi,01.25.1855 Commented Apr 1, 2015 at 14:07
  • Have you tried debugging? Commented Apr 1, 2015 at 14:09
  • 1
    Please add any clarification to your question itself (using the edit link) - not in the comments please. Commented Apr 1, 2015 at 14:23

1 Answer 1

Reset to default
2

Do the following:

  1. check the content of the file, how many ',' char does it have in each line, it should have at least 2
  2. check the size of the array, it should be at least 3 in each read iteration, since you are accessing array[2]

It seems that the array at a certain line or iteration doesn't have 3 items, maybe one or two.

example:

line 1: aaa,bbb,ccc   //2 ',' => array={"aaa","bbb","ccc"} this is fine
line 2: ddd,eee       //1 ',' => array={"ddd","eee"} this causes the
                      // exception since array[2] does not exist NULL
line 3: empty         //0 ',' => array={} this causes the exception

If you are not sure of what is happening run the following code:

    try(Reader reader = new FileReader(this.file);
            BufferedReader br = new BufferedReader(reader)) {
        connection = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/myBook", this.userName,
                this.pass);

        Statement statement = connection.createStatement();
        String str;          
        while((str = br.readLine()) != null&&str.split(",").length>=3){

            String[] array = str.split(",");
            statement.executeUpdate("Insert Into myBook.book 
(name,author,pubDate) values('"+array[0]+"', '"+ array[1]+"', '"+array[2]+"')");
        }

    }

If the above code run without error then at least one line doesn't have 2 ',' chars if the application still firing the same error then it will be something else.

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1 Comment

it contains 2 ',' chars and i checked the array, its size is 3

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