Java将字符串解析为Int

Question

This is my code to ask the database for all users which I save later to a txt-file line-by-line. Works good so far except for the String steamid .

public String getAllUsers() {
    Connection conn = null;
    Statement stmt = null;
    try {
        Path out = Paths.get("C:\\Teamspeak\\alluserlist.txt");
        List<String> arrayList = new ArrayList<String>();
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection(DB_URL, dbUser, dbUserPW);
        stmt = conn.createStatement();
        String sql = "select nickname, unique_id, is_admin, steamid, is_banned from users where nickname not like 'Unknown from%'";
        ResultSet rs = stmt.executeQuery(sql);
        while (rs.next()) {
            String nickname = rs.getString("nickname");
            String id = rs.getString("unique_id");
            String admin = rs.getString("is_admin");
            String steamid = String.valueOf(rs.getString(4));
            String banned = rs.getString("is_banned");

            int steamnr = Integer.parseInt(steamid.replaceAll("[\\s|\\u00A0]+", ""));

            //System.out.println(nickname + ":" + id + ":" + admin + ":" + steamid);
            if (!nickname.equals("")) {
                if (Integer.valueOf(banned) == 1) {
                    nickname = "<s>" + nickname + "</s>";
                    id = "banned";

                    // <a href="somepage.html" target=newtab>text</a>

                    arrayList.add(nickname + ";" + id + ";" + admin + ";" + "<a href=\"http://steamcommunity.com/profiles/" + steamnr + "\"target=newtab>go to Steam</a>");
                } else {
                    arrayList.add(nickname + ";" + id + ";" + admin + ";" + "<a href=\"http://steamcommunity.com/profiles/" + steamnr + "\"target=newtab>go to Steam</a>");
                }

            }               
        }
        try {   
            Charset charset = Charset.forName("UTF-8");
            Files.write(out,arrayList, charset);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        rs.close();
        stmt.close();
        conn.close();
    } catch (SQLException se) {
        se.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (stmt != null)
                stmt.close();
        } catch (SQLException se2) {
        }
        try {
            if (conn != null)
                conn.close();
        } catch (SQLException se) {
            se.printStackTrace();
        }
    }
    return "error";
}

I tried to remove whitespaces using

int steamnr = Integer.parseInt(steamid.replaceAll("[\\s|\\u00A0]+", ""));

but it shows no effect.

What am I doing wrong?

 java.lang.NumberFormatException: For input string: " 7 6 5 6 1 1 9 8 0 5 7 5 9 7 5 3 1"
            at java.lang.NumberFormatException.forInputString(Unknown Source)
            at java.lang.Integer.parseInt(Unknown Source)
            at java.lang.Integer.parseInt(Unknown Source)
            at database.DatabaseHandler.getAllUsers(DatabaseHandler.java:329)
            at main.Main.main(Main.java:139)
            at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
            at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
            at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
            at java.lang.reflect.Method.invoke(Unknown Source)
            at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)

steamid is a varchar in database

Answer 1

Seems like your number is too big for an Integer. Try parsing it as Long

String steamid = " 7 6 5 6 1 1 9 8 0 5 7 5 9 7 5 3 1";
Long steamnr = Long.parseLong(steamid.replaceAll("[\\s|\\u00A0]+", ""));
System.out.println(steamnr);

Answer 2

Even if you remove all blanks (which you don't, as the error message shows), the number is too big to fit into an Integer object. So you need to use a data type capable of storing larger values.

I would advice you to use the class BigInteger to store such values, as there is likely no guarantee that it won't exceed the range of Long as well.

Answer 3

It seems that even if they are displayed as whitespaces, \\\\s is not removing them, so they may be other characters.

The way to still remove them regardless of them being whitespaces or not, is to remove all non-digits , by replacing this:

steamid.replaceAll("[\\s|\\u00A0]+", "")

with this:

steamid.replaceAll("\\D+", "")

Also, that number is too big to fit in an int , you should use a long instead (or a BigInteger , as others suggested):

long steamnr = Long.parseLong(steamid.replaceAll("\\D+", ""));

Demo here