src/main/java/net/jaekl/squelch/Squelch.java

   1 package net.jaekl.squelch;
   2
   3 import java.io.IOException;
   4 import java.io.PrintWriter;
   5 import java.sql.Connection;
   6 import java.sql.SQLException;
   7 import java.util.Locale;
   8
   9 import net.jaekl.squelch.db.DbDriver;
  10 import net.jaekl.squelch.db.MsSqlDriver;
  11 import net.jaekl.squelch.db.MySqlDriver;
  12 import net.jaekl.squelch.db.OracleDriver;
  13 import net.jaekl.squelch.db.PostgresqlDriver;
  14 import net.jaekl.squelch.stmt.Select;
  15 import net.jaekl.squelch.stmt.Stmt;
  16 import net.jaekl.squelch.util.ConsoleInput;
  17 import net.jaekl.squelch.util.ConsoleInputImpl;
  18 import net.jaekl.squelch.util.ConsoleUtil;
  19
  20 public class Squelch {
  21         static final String PROMPT = "> ";
  22         private static final DbDriver[] DB_DRIVERS = {
  23                 new MsSqlDriver(),
  24                 new MySqlDriver(),
  25                 new OracleDriver(),
  26                 new PostgresqlDriver()
  27         };
  28         private static final Stmt[] READ_ONLY_STATEMENTS = {
  29                 new Select()
  30         };
  31
  32         private Args m_args;
  33         private Stmt[] m_statements;
  34
  35         public Squelch() {
  36                 m_args = new Args(this.getClass().getName());
  37                 m_statements = READ_ONLY_STATEMENTS;
  38         }
  39
  40         public void doMain(String[] params)
  41         {
  42                 try (PrintWriter pw = new PrintWriter(System.out))
  43                 {
  44                         if (!m_args.parseArgs(pw, params)) {
  45                                 return;
  46                         }
  47
  48                         ConsoleInputImpl ci = ConsoleUtil.getInst().getInput();
  49                         pumpLines(pw, ci);
  50                 } catch (IOException | ClassNotFoundException | SQLException | SquelchException e) {
  51                         e.printStackTrace();
  52                 }
  53         }
  54
  55         public static void main(String[] args) {
  56                 new Squelch().doMain(args);
  57         }
  58
  59         boolean isQuit(String line)
  60         {
  61                 if ((null == line)) {
  62                         return true;
  63                 }
  64                 String trimmed = line.trim();
  65                 if (trimmed.endsWith(";")) {
  66                         trimmed = trimmed.substring(0, trimmed.length() - 1).trim();
  67                 }
  68                 String upperCased = trimmed.toUpperCase(Locale.CANADA);
  69
  70                 if (  "EXIT".equals(upperCased)
  71                    || "QUIT".equals(upperCased)
  72                    || "\\q".equals(trimmed) )
  73                 {
  74                         return true;
  75                 }
  76                 return false;
  77         }
  78
  79         Connection getConnection() throws ClassNotFoundException, SQLException, SquelchException
  80         {
  81                 String jdbcUrl = m_args.getUrl();
  82                 DbDriver driver = getDriverFor(jdbcUrl);
  83
  84                 return driver.connect(jdbcUrl, m_args.getUser(), m_args.getPass());
  85         }
  86
  87         DbDriver getDriverFor(String jdbcUrl) throws SquelchException
  88         {
  89                 for (DbDriver driver : DB_DRIVERS) {
  90                         if (driver.handles(jdbcUrl)) {
  91                                 return driver;
  92                         }
  93                 }
  94                 throw new SquelchException("Cannot determine DB Driver for JDBC URL:  \"" + jdbcUrl + "\".");
  95         }
  96
  97         void pumpLines(PrintWriter pw, ConsoleInput ci) throws IOException, ClassNotFoundException, SQLException, SquelchException
  98         {
  99                 String line = null;
 100                 try (Connection conn = getConnection())
 101                 {
 102                         while (true) {
 103                                 boolean processed = false;
 104                                 line = ci.readLine(PROMPT);
 105
 106                                 for (Stmt statement : m_statements) {
 107                                         if (statement.handles(line)) {
 108                                                 statement.exec(conn, pw, line);
 109                                                 processed = true;
 110                                                 break;
 111                                         }
 112                                 }
 113
 114                                 if ((!processed)) {
 115                                         if (isQuit(line)) {
 116                                                 break;
 117                                         }
 118                                         // Unrecognized command
 119                                         // TODO:  add a string table, and a natural-language error message.
 120                                         pw.println("??? \"" + line + "\"");
 121                                         pw.flush();
 122                                 }
 123                         }
 124                 }
 125         }
 126 }