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.PSet;
  16 import net.jaekl.squelch.stmt.Select;
  17 import net.jaekl.squelch.stmt.Stmt;
  18 import net.jaekl.squelch.util.ConsoleInput;
  19 import net.jaekl.squelch.util.ConsoleInputImpl;
  20 import net.jaekl.squelch.util.ConsoleUtil;
  21
  22 public class Squelch {
  23         static final String PROMPT = "> ";
  24         private static final DbDriver[] DB_DRIVERS = {
  25                 new MsSqlDriver(),
  26                 new MySqlDriver(),
  27                 new OracleDriver(),
  28                 new PostgresqlDriver()
  29         };
  30         private static final Stmt[] READ_ONLY_STATEMENTS = {
  31                 new Describe(),
  32                 new PSet(),
  33                 new Select()
  34         };
  35
  36         private Args m_args;
  37         private Stmt[] m_statements;
  38
  39         public Squelch() {
  40                 m_args = new Args(this.getClass().getName());
  41                 m_statements = READ_ONLY_STATEMENTS;
  42         }
  43
  44         public void doMain(String[] params)
  45         {
  46                 try (PrintWriter pw = new PrintWriter(System.out))
  47                 {
  48                         if (!m_args.parseArgs(pw, params)) {
  49                                 return;
  50                         }
  51
  52                         ConsoleInputImpl ci = ConsoleUtil.getInst().getInput();
  53                         pumpLines(pw, ci);
  54                 } catch (IOException | ClassNotFoundException | SQLException | SquelchException e) {
  55                         e.printStackTrace();
  56                 }
  57         }
  58
  59         public static void main(String[] args) {
  60                 new Squelch().doMain(args);
  61         }
  62
  63         boolean isQuit(String line)
  64         {
  65                 if ((null == line)) {
  66                         return true;
  67                 }
  68                 String trimmed = line.trim();
  69                 if (trimmed.endsWith(";")) {
  70                         trimmed = trimmed.substring(0, trimmed.length() - 1).trim();
  71                 }
  72                 String upperCased = trimmed.toUpperCase(Locale.CANADA);
  73
  74                 if (  "EXIT".equals(upperCased)
  75                    || "QUIT".equals(upperCased)
  76                    || "\\q".equals(trimmed) )
  77                 {
  78                         return true;
  79                 }
  80                 return false;
  81         }
  82
  83         Connection getConnection(DbDriver driver, String jdbcUrl)
  84                 throws ClassNotFoundException, SQLException, SquelchException
  85         {
  86                 return driver.connect(jdbcUrl, m_args.getUser(), m_args.getPass());
  87         }
  88
  89         DbDriver getDriverFor(String jdbcUrl) throws SquelchException
  90         {
  91                 for (DbDriver driver : DB_DRIVERS) {
  92                         if (driver.handles(jdbcUrl)) {
  93                                 return driver;
  94                         }
  95                 }
  96                 throw new SquelchException("Cannot determine DB Driver for JDBC URL:  \"" + jdbcUrl + "\".");
  97         }
  98
  99         void pumpLines(PrintWriter pw, ConsoleInput ci) throws IOException, ClassNotFoundException, SQLException, SquelchException
 100         {
 101                 String line = null;
 102                 String jdbcUrl = m_args.getUrl();
 103                 DbDriver driver = getDriverFor(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 (Connection conn = getConnection(driver, jdbcUrl)){
 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 }