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Simple H2 Database utility class

/ Published in: Java
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A simple utility class that uses the H2 SQL Db to maintain a database connection. It also gives a convenience method to run SQL scripts.

_Note:_The init.sql value is hardcoded, and should be replaced by a static variable if needed

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  1. package db;
  2.  
  3. import java.sql.Connection;
  4. import java.sql.DriverManager;
  5. import java.sql.SQLException;
  6. import java.sql.Statement;
  7. import java.util.logging.Level;
  8. import java.util.logging.Logger;
  9. import org.h2.tools.DeleteDbFiles;
  10.  
  11. public class DbUtil {
  12.     private static Connection myConnection = null;
  13.  
  14.     static {
  15.         try {
  16.             Class.forName("org.h2.Driver");
  17.         } catch (ClassNotFoundException ex) {
  18.             Logger.getLogger(DbUtil.class.getName()).log(Level.SEVERE, null, ex);
  19.         }
  20.     }
  21.  
  22.  
  23.     public static void setupConn(String theDbPath) throws SQLException {
  24.         if(null == myConnection || myConnection.isClosed()) {
  25.             myConnection = DriverManager.getConnection("jdbc:h2:"+theDbPath);
  26.         }
  27.     }
  28.  
  29.     public static Statement getStatement() throws SQLException {
  30.         if(null==myConnection || myConnection.isClosed()) {
  31.             SQLException ex = new SQLException("No valid database connection!");
  32.             Logger.getLogger(DbUtil.class.getName()).log(Level.SEVERE, null, ex);
  33.             throw ex;
  34.         }
  35.  
  36.         return myConnection.createStatement();
  37.     }
  38.  
  39.     public static void closeConn() throws SQLException {
  40.         myConnection.close();
  41.     }
  42.  
  43.     public static void setupDB(String theDbPath) throws SQLException  {
  44.  
  45.         setupConn(theDbPath);
  46.         runScript("init.sql");
  47.     }
  48.  
  49.     public static void runScript(String thePath) throws SQLException {
  50.  
  51.         Statement stat = getStatement();
  52.         stat.execute("runscript from '"+thePath+"'");
  53.         stat.close();
  54.     }
  55.  
  56.     public static void resetDB(String theDbPath) throws Exception {
  57.         // to separate the dbname from the path
  58.         int lastSlash = theDbPath.lastIndexOf('/');
  59.  
  60.  
  61.         DeleteDbFiles.execute(theDbPath.substring(0,lastSlash), 
  62.                               theDbPath.substring(lastSlash), 
  63.                               true);
  64.  
  65.         setupDB(theDbPath);
  66.     }
  67.  
  68. }

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