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POException thrown while retrieving image from mysql database
 

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  1. POException thrown while retrieving image from mysql database
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    <p>I want to store image in binary format and retrieve it in binary format and display it in image format. I am able to store the file in binary format, but while retrieving it I get error java null pointer exception. Please point out the error. Here is the code:</p> <pre><code>import java.awt.Image; import java.awt.Toolkit; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class InsertImageTest { int len; /** * This is used to get the Connection * * @return */ public Connection getConnection() { Connection connection = null; Statement stmt = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection( "jdbc:mysql://localhost:3306/test", "root", "spanwave"); } catch (Exception e) { System.out.println("Error Occured While Getting the Connection: - " + e); } return connection; } /** * Insert Image */ public Image getImageFile(String fileName) throws Exception { InsertImageTest ins= new InsertImageTest(); Connection con=ins.getConnection(); Statement stmt=con.createStatement(); // String baseName=StoreImage.getBaseName(fileName); ResultSet rs=stmt.executeQuery("select * from trn_imgs where img_title='"+"Honda Car"+"'"); if (!rs.next()) { System.out.println("Image:"+"honda car"+" not found"); return null; } // int len=rs.getInt(2); byte [] b=new byte[len]; InputStream in = rs.getBinaryStream(3); int n=in.read(b); System.out.println("n: "+n); in.close(); Image img=Toolkit.getDefaultToolkit().createImage(b); System.out.println("Image: "+"honda car"+" retrieved ok, size: "+len); return img; } public void insertImage() throws IOException { Connection connection = null; PreparedStatement statement = null; FileInputStream inputStream = null; try { File image = new File("calender.png"); inputStream = new FileInputStream(image); len=inputStream.available(); connection = getConnection(); statement = connection .prepareStatement("insert into trn_imgs(img_title, img_data) " + "values(?,?)"); statement.setString(1, "Honda Car"); statement.setBinaryStream(2, (InputStream) inputStream, (int) (image.length())); statement.executeUpdate(); } catch (FileNotFoundException e) { System.out.println("FileNotFoundException: - " + e); } catch (SQLException e) { System.out.println("SQLException: - " + e); } finally { try { connection.close(); statement.close(); } catch (SQLException e) { System.out.println("SQLException Finally: - " + e); } } } /*** * Execute Program * * @param args * @throws Exception */ public static void main(String[] args) throws Exception { InsertImageTest imageTest = new InsertImageTest(); imageTest.insertImage(); Image img= imageTest.getImageFile("calender.png"); } } </code></pre>
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    1. UStrashgod
    1. This table or related slice is empty.
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    2. PL
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      1. VTUpMod
    2. VO
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      1. VTUpMod
    1. COWhere do you get the NPE? What does the stack trace say?
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      1. UScreinig
    2. COYou need to learn how to debug your code, identify which lines causes the null pointer exception
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      1. USgerrytan
    3. COAddendum to the good comment by @gerrytan: [learn to read stack traces](http://stackoverflow.com/questions/12688068/how-to-read-and-understand-the-java-stack-trace). It's IMHO one of the core skills in java development.
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