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.Describe;
  15 import net.jaekl.squelch.stmt.Select;
  16 import net.jaekl.squelch.stmt.Stmt;
  17 import net.jaekl.squelch.util.ConsoleInput;
  18 import net.jaekl.squelch.util.ConsoleInputImpl;
  19 import net.jaekl.squelch.util.ConsoleUtil;
  20
  21 public class Squelch {
  22         static final String PROMPT = "> ";
  23         private static final DbDriver[] DB_DRIVERS = {
  24                 new MsSqlDriver(),
  25                 new MySqlDriver(),
  26                 new OracleDriver(),
  27                 new PostgresqlDriver()
  28         };
  29         private static final Stmt[] READ_ONLY_STATEMENTS = {
  30                 new Describe(),
  31                 new Select()
  32         };
  33
  34         private Args m_args;
  35         private Stmt[] m_statements;
  36
  37         public Squelch() {
  38                 m_args = new Args(this.getClass().getName());
  39                 m_statements = READ_ONLY_STATEMENTS;
  40         }
  41
  42         public void doMain(String[] params)
  43         {
  44                 try (PrintWriter pw = new PrintWriter(System.out))
  45                 {
  46                         if (!m_args.parseArgs(pw, params)) {
  47                                 return;
  48                         }
  49
  50                         ConsoleInputImpl ci = ConsoleUtil.getInst().getInput();
  51                         pumpLines(pw, ci);
  52                 } catch (IOException | ClassNotFoundException | SQLException | SquelchException e) {
  53                         e.printStackTrace();
  54                 }
  55         }
  56
  57         public static void main(String[] args) {
  58                 new Squelch().doMain(args);
  59         }
  60
  61         boolean isQuit(String line)
  62         {
  63                 if ((null == line)) {
  64                         return true;
  65                 }
  66                 String trimmed = line.trim();
  67                 if (trimmed.endsWith(";")) {
  68                         trimmed = trimmed.substring(0, trimmed.length() - 1).trim();
  69                 }
  70                 String upperCased = trimmed.toUpperCase(Locale.CANADA);
  71
  72                 if (  "EXIT".equals(upperCased)
  73                    || "QUIT".equals(upperCased)
  74                    || "\\q".equals(trimmed) )
  75                 {
  76                         return true;
  77                 }
  78                 return false;
  79         }
  80
  81         Connection getConnection(DbDriver driver, String jdbcUrl)
  82                 throws ClassNotFoundException, SQLException, SquelchException
  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                 String jdbcUrl = m_args.getUrl();
 101                 DbDriver driver = getDriverFor(jdbcUrl);
 102
 103                 try (Connection conn = getConnection(driver, jdbcUrl))
 104                 {
 105                         while (true) {
 106                                 boolean processed = false;
 107                                 line = ci.readLine(PROMPT);
 108
 109                                 for (Stmt statement : m_statements) {
 110                                         if (statement.handles(line)) {
 111                                                 try {
 112                                                         statement.exec(driver, conn, pw, line);
 113                                                 }
 114                                                 catch (SQLException exc) {
 115                                                         exc.printStackTrace(pw);
 116                                                 }
 117                                                 processed = true;
 118                                                 break;
 119                                         }
 120                                 }
 121
 122                                 if ((!processed)) {
 123                                         if (isQuit(line)) {
 124                                                 break;
 125                                         }
 126                                         // Unrecognized command
 127                                         // TODO:  add a string table, and a natural-language error message.
 128                                         pw.println("??? \"" + line + "\"");
 129                                 }
 130                                 pw.flush();
 131                         }
 132                 }
 133         }
 134 }