Building the Android JDBC Driver

The JDBC API is an alternative to the drop-in replacement. It is possible to build Berkeley DB SQL for Android in such a way that a JDBC API is exposed to Android application developers. This is done using the Android NDK.

This section describes how to build and use the BDB JDBC driver for Android. Note that the BDB JDBC driver cannot currently be built on a Windows platform.

  1. Download and install the Android SDK. The installation instructions can be found here:

    http://developer.android.com/sdk/installing.html

  2. Download and install the Android NDK. It can be found here:

    http://developer.android.com/sdk/ndk/index.html

  3. Build the BDB JDBC libraries.

    1. If you do not already have it, download the Berkeley DB package from here:

      http://www.oracle.com/technetwork/database/berkeleydb/downloads/index.html

      Note that you must be using a 5.3.x or higher version of the product in order for these instructions to work. Once you have the package, unpack it:

      $ tar zxvf db-x.y.z.tar.gz
      $ cd db-x.y.z

      Where x.y.z the major, minor, and point release version of the Berkeley DB distribution which you are using.

      Also, note that in the following instructions, the directory denoted by db-x.y.z, above, is referred to as <db>.

    2. Build an x86/x64 JDBC package. This is required because the building process will generate target files which are required to build Android NDK. Also, the built JAR file can be imported by eclipse, which will then convert it to the Android Dalvik JAR format.

      To do this, edit <db>/lang/sql/jdbc/SQLit/Database.java and replace all instances of System.loadLibrary("sqlite_jni") with System.loadLibrary("oracle-jdbc").

      Once you have done this, configure and make the library. The following example shows the minimum configuration options that you need to use in order to configure the Berkeley DB JDBC driver. For your particular installation, other configuration options might be interesting to you. See Configuring Berkeley DB and Android Configuration Options for more information.

      cd <db>/build_unix
      ../dist/configure --enable-jdbc && make
  4. Enable encryption if required.

    By default, encryption is disabled. To enable it, edit <db>/build_android/jdbc/jni/Android.mk and change BDB_ENABLE_ENCRYPTION from false to true.

    After enabling encryption, use pragma key to set the password. You must do this before performing any database operations. For example:

     # ./dbsql test.db
    dbsql> pragma key="xyzzy";
    dbsql> create table t1(x);
    dbsql> .quit
    
    # ./dbsql test.db
    dbsql> pragma key="xyzzy";
    dbsql> .tables
    t1 
  5. Build the Android NDK:

    $ cd <db>/build_android/jdbc/jni
    $ <ndk-install-directory>/ndk-build 

    This results in the following required files:

    <db>/build_android/jdbc/libs/armeabi/liboracle-jdbc.so
    <db>/build_android/jdbc/libs/armeabi/dbsql
    <db>/build_unix/jdbc/sqlite.jar

Having built the JDBC driver, you can now use it with your project. You can do this using Eclipse and the ADT plugin, which you can get from here:

http://developer.android.com/sdk/eclipse-adt.html

To make sure everything is working:

  1. Start Eclipse and create an Android project. Use:

    • test_jdbc as the Android project name.

    • Create it as an Android 3.2 project.

    • For the package name, use example.jdbc.

  2. This results in an empty code file. Copy and paste the following example code into that file:

    package example.testjdbc;
    
    import SQLite.*;
    import java.io.*;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.widget.TextView;
    import java.sql.*;
    
    public class Test_jdbcActivity extends Activity {
    
        /*
         * This is the main entrance/body of our sample program. This
         * example illustrates all of the major API usages.
         */
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            TextView tv = new TextView(this);
            tv.setText("App Started");
            setContentView(tv);
    
            System.out.println("Appstart: ");
    
            String url = 
                "jdbc:sqlite://data/data/example.testjdbc/example.db";
            Connection con;
            String dropString = "drop table if exists COFFEES";
            String createString;
            createString = "create table COFFEES " 
                + "(COF_NAME varchar(32), "
                + "SUP_ID int, " + "PRICE float, " + "SALES int, "
                + "TOTAL int)";
            String insertString = "drop table COFFEES if exisits";
            String query = "select COF_NAME, PRICE from COFFEES";
            Statement stmt;
    
            try {
                Class.forName("SQLite.JDBCDriver");
    
            } catch (java.lang.ClassNotFoundException e) {
                System.err.print("ClassNotFoundException: ");
                System.err.println(e.getMessage());
            }
    
            try {
                con = 
                    DriverManager.getConnection(url, "myLogin", "myPW");
    
                stmt = con.createStatement();
                stmt.executeUpdate(dropString);
                stmt.executeUpdate(createString);
                stmt.close();
    
                stmt = con.createStatement();
                stmt.executeUpdate("insert into COFFEES "
                    + "values('Colombian', 00101, 7.99, 0, 0)");
    
                stmt.executeUpdate("insert into COFFEES "
                    + "values('French_Roast', 00049, 8.99, 0, 0)");
    
                stmt.executeUpdate("insert into COFFEES "
                    + "values('Espresso', 00150, 9.99, 0, 0)");
    
                stmt.executeUpdate("insert into COFFEES "
                    + "values('Colombian_Decaf', 00101, 8.99, 0, 0)");
    
                stmt.executeUpdate("insert into COFFEES "
                    + "values('French_Roast_Decaf', 00049, 9.99, 0, 0)");
    
                ResultSet rs = stmt.executeQuery(query);
    
                System.out.println("Coffee Break Coffees and Prices:");
                while (rs.next()) {
                    String s = rs.getString("COF_NAME");
                    float f = rs.getFloat("PRICE");
                    System.out.println(s + "   " + f);
                }
                stmt.close();
                con.close();
    
            } catch (SQLException ex) {
                System.err.println("SQLException: " + ex.getMessage());
            }
        }
    } 
  3. Copy the following files into place:

    $ cd <workspace>/test_jdbc
    $ mkdir -p libs/armeabi
    $ cp -r <db>/build_android/jdbc/libs/armeabi/liboracle-jdbc.so \
    libs/armeabi
    $ cp -r <db>/build_unix/jdbc/sqlite.jar libs
  4. Back in Eclipse, right click the project name, and select the refresh option to reload the project from the directory. The two new files that were copied into place in the previous step are now included in the project view.

  5. Convert the JAR file to the Android Dalvik format:

    1. Right-click on your project.

    2. Choose Build Path -> Configure Build Path

    3. Click the Libraries tab.

    4. Click Add JARS.

  6. Run the project:

    1. Choose Property -> Android and select any one of the usable build targets.

    2. Right click the project. Choose Run As -> Android

  7. Verify your installation. After a short pause (depending on the speed of your system), the application logo is displayed. Use the Android adb command line application to make sure the application is running as expected:

    $ cd <android-sdk>/platform-tools
    $ ./adb logcat
    I/System.out(  539): Appstart: 
    I/System.out(  539): Coffee Break Coffees and Prices:
    I/System.out(  539): Colombian   7.99
    I/System.out(  539): French_Roast   8.99
    I/System.out(  539): Espresso   9.99
    I/System.out(  539): Colombian_Decaf   8.99
    I/System.out(  539): French_Roast_Decaf   9.99

    You can also check if the database (example.db) exists in the emulator:

    $ ./adb shell ls /data/data/example.testjdbc
    example.db
    example.db-journal
    lib 

    Finally, check the database using the BDB SQL shell:

    $ ./adb push <db>/build_android/jdbc/libs/armeabi/dbsql \
    /data/data/example.testjdbc
    326 KB/s (1293760 bytes in 3.865s)
    $ ./adb shell
    root@android:/ # cd /data/data/example.testjdbc
    root@android:/data/data/example.testjdbc # ./dbsql example.db
    Berkeley DB 11g Release 2, library version 11.2.5.2.36
    Enter ".help" for instructions
    Enter SQL statements terminated with a ";"
    dbsql> .tables
    COFFEES
    dbsql> select * from COFFEES;
    Colombian|101|7.99|0|0
    French_Roast|49|8.99|0|0
    Espresso|150|9.99|0|0
    Colombian_Decaf|101|8.99|0|0
    French_Roast_Decaf|49|9.99|0|0
    dbsql> .quit