Android Database Table export to CSV – Part 1


The best way to export data out of Android Sqlite database is create a copy the DB file into the SDCard.

Copy the Android database into DB File –

Advantages –

  • The import and export of the database would be a lot easy.
  • All tables could be backed up using a single file. ( This can have the backup of the user defined configuration of the program also ).

Disadvantages –

  • We need special tools to read this DB file which makes it difficult to be portable.

Copy a table into CSV file –

Advantages –

  • Only data required by the user can be given.
  • It is the more readable and portable format.

In my application I have decided to have both this methods. Will be updating soon.

Create a Alert Dialog in Android


Dialogs are generally used to display the the intermediate data like Status Messages, Warning Messages or Error Messages.

In this post we will go through how to create a Dialog Box in Android App development –

  • Create a function will call the Alert Dialog (AddEx is the activity. You can use your activity name over here ).
  1: private void displayDialog(String str1)
  2: {
  3:   AlertDialog.Builder builder = new AlertDialog.Builder(AddEx.this);
  4:   builder.setMessage(str1);
  5:   builder.setCancelable(false);
  6:   builder.setTitle("Status");
  7:   builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
  8:          @Override
  9:          public void onClick(DialogInterface dialog, int id) {
 10:           AddEx.this.finish();
 11:          }
 12:        });
 13:   AlertDialog alert = builder.create();
 14:   alert.show();
 15: }

  • Call this function anywhere in your activity class.
  1:  if(status == true)
  2:  {
  3:   displayDialog("Completed Successfully");
  4:  }
  5:  else
  6:  {
  7:    displayDialog("Error inserting into Table");
  8:  }
  • In the Alert Dialog you can also implement builder.setNegativebutton() method to have “CANCEL” part included in the dialog. Implementation is similar to setPositiveButton.

How to compile JAVA Project into a single JAR File using NetBeans


I found an interesting article about compiling a NetBeans project into a single JAR file.

<?xml version="1.0" encoding="UTF-8"?>
<project name="build-OneJar1" default="all" basedir="..">
   <target name="package-for-store" depends="jar">

        <!– Change the value of this property to be the name of your JAR,
             minus the .jar extension. It should not have spaces.
             <property name="store.jar.name" value="MyJarName"/>
        –>
        <property name="store.jar.name" value="MyProject"/>

        <!– don’t edit below this line –>

        <property name="store.dir" value="store"/>
        <property name="store.jar" value="${store.dir}/${store.jar.name}.jar"/>

        <echo message="Packaging ${application.title} into a single JAR at ${store.jar}"/>

        <delete dir="${store.dir}"/>
        <mkdir dir="${store.dir}"/>

        <jar destfile="${store.dir}/temp_final.jar" filesetmanifest="skip">
            <zipgroupfileset dir="dist" includes="*.jar"/>
            <zipgroupfileset dir="dist/lib" includes="*.jar"/>

            <manifest>
                <attribute name="Main-Class" value="${main.class}"/>
            </manifest>
        </jar>

        <zip destfile="${store.jar}">
            <zipfileset src="${store.dir}/temp_final.jar"
            excludes="META-INF/*.SF, META-INF/*.DSA, META-INF/*.RSA"/>
        </zip>

        <delete file="${store.dir}/temp_final.jar"/>

    </target>
</project>
  • Save the above code as build-OneJar.xml and save it in the NetBeans project folder.( I saved in the nbproject folder and also had the file as a ANT project file.).

  • In Build.xml put an import statement and import the build-onejar.xml file.

  • To build the NetBeans project into a single JAR file, it needs to be run using the specified parameters as TARGET. To do this Right Click build.xml in the Files TAB and select Run Target –> Other Targets –> Package-For-Store.

  • The JAR file will be built and stored in a folder called Store in the
  • Also remember to save the build-onejar.xml file as a template for future use. To do this go right click on the file in the Files TAB and select Save As Template….. select the appropriate folder and click OK.

 

  In this way a NetBeans project can be compiled into a single JAR file.

Sources

http://java.sun.com/developer/technicalArticles/java_warehouse/single_jar/

How to use SQLite with Java using NetBeans IDE


  • SQLite is an embedded database which will have all the tables stored in a db file. This saves the trouble of having to setup database servers everytime we develop a new programs. Android uses SQLite as a database.
  • I was browsing through the net on how to use SQLite for a small app I was developing. I came across this page which had very good directions on how to use SQLite with Java.

1. SQLite is serverless. With SQLiteJDBC driver, we can write programs to access SQLite using JAVA.
This tutorial will have step by step description about how to do it.
2. We will use Netbeans, but it will work in the same manner with eclipse too.
3. Download SQLiteJDBC driver jar, ‘sqlitejdbc-v056.jar’ from website: http://www.zentus.com/sqlitejdbc/
4. Create a java project named ‘SQLite’ in Netbeans.(You can give any name
5. Create a class called ‘Test’ in that project.
6. Add ‘sqlitejdbc-v056.jar’ in the class path of ‘SQLite’ project in Netbeans.
7. Paste following code in Test class
—>
import java.sql.*;
public class Test {
public static void main(String[] args) throws Exception {
Class.forName("org.sqlite.JDBC");
Connection conn =
DriverManager.getConnection("jdbc:sqlite:Vinit");
Statement stat = conn.createStatement();
stat.executeUpdate("drop table if exists school;");
stat.executeUpdate("create table school (name, state);");
PreparedStatement prep = conn.prepareStatement(
"insert into school values (?, ?);");
prep.setString(1, "UTD");
prep.setString(2, "texas");
prep.addBatch();
prep.setString(1, "USC");
prep.setString(2, "california");
prep.addBatch();
prep.setString(1, "MIT");
prep.setString(2, "massachusetts");
prep.addBatch();
conn.setAutoCommit(false);
prep.executeBatch();
conn.setAutoCommit(true);
ResultSet rs = stat.executeQuery("select * from school;");
while (rs.next()) {
System.out.print("Name of School = " + rs.getString("name") + " ");
System.out.println("state = " + rs.getString("state"));
}
rs.close();
conn.close();
}
}
—>
8. Run the project as java application.
9. It will create database file by name ‘Vinit’ in the Netbeans ‘SQLite’ project folder.
10. Here is in above code, we are creating sqlite database ‘Vinit’.

  • In NetBeans add libraries by going to Tools –> Libraries and Click ADD LIBRARY. An Add Library dialog will appear

  • Add the driver JAR file location into CLASSPATH tab

  • In the Projects window Right Click on Libraries folder and Select Add Library

Click on Add Library and select Sqlite3.

Sources:

http://en.wikibooks.org/wiki/Java_JDBC_using_SQLite/Connecting

http://tech-britney.blogspot.com/2010/07/using-sqlite-with-sqlitejdbc-driver.html