java - My array list to .txt file program is giving me several errors -

i have inventory application sets list of strings based on user input. supposed export strings .txt file. have never used filewriter before, , stuck.

any appreciated.

here relevant code:

the 3 lines near end have 'writer.' in them giving me unreported exception ioexception; must caught or declared thrown.

import java.util.*; import java.io.filewriter;  public class mventory extends javax.swing.jframe {      /**      * creates new form mventory      */     public mventory() {         initcomponents();      }      public class productinfo {          string name;         string des;         string id;         string num;          public productinfo(string name, string des, string id, string num) {             this.name = name;             this.des = des;             this.id = id;             this.num = num;         }     }      public static void inventory() {      }      //creat array     arraylist<string> inventory = new arraylist<string>();      private void addgoactionperformed(java.awt.event.actionevent evt) {         // add item         string name, description, identification, number, item;          name = namein.gettext();         description = desin.gettext();         identification = idin.gettext();         number = numin.gettext();          item = "" + name + "," + description + "," + identification + "," + number + ".";          inventory.add(new string(item));          namein.settext("");         desin.settext("");         idin.settext("");         numin.settext("");      }      private void exportgoactionperformed(java.awt.event.actionevent evt) {         filewriter writer;         writer = new filewriter("inventory.txt");         (string str : inventory) {             writer.write(str);         }         writer.close();     } } 

you need try/catch statement around writer.

such as:

private void exportgoactionperformed(java.awt.event.actionevent evt) {     filewriter writer = null;     try {         writer = new filewriter("inventory.txt");         (string str : inventory) {             writer.write(str);         }     } catch (ioexception e) {         //handle exception, rethrow or log         e.printstacktrace();     } {         try {             writer.close();         } catch (ioexception ignore){          }     }  }