Comparing values from resultset in java

Question

I have created a method which produces a ResultSet with 1 row and 31 columns with with some column value being 1,2 or 0.I want to create a method which gives only those column name and values whose value is 1.

I tried in this way

int status[] = {0, 2};
public int[][] beam_CurrentStatus() {
  int arr[][] = new int[1][31];
  int i = 0;
  try

  {
    con = getConnection();
    stmt = con.createStatement();

    String sql = "SELECT TOP 1 c.logtime, a.BL1_data_SS_ST,a.BL2_data_SS_ST,a.BL3_data_SS_ST,a.BL4_data_SS_ST,a.BL5_data_SS_ST,a.BL6_data_SS_ST,a.BL7_data_SS_ST,a.BL8_data_SS_ST,a.BL9_data_SS_ST,a.BL10_data_SS_ST,a.BL11_data_SS_ST, a.BL12_data_SS_ST,a.BL13_data_SS_ST,a.BL14_data_SS_ST,a.BL15_data_SS_ST,a.BL16_data_SS_ST,a.BL17_data_SS_ST,a.BL18_data_SS_ST,a.BL19_data_SS_ST,a.BL20_data_SS_ST,a.BL21_data_SS_ST,a.BL22_data_SS_ST,a.BL23_data_SS_ST,a.BL24_data_SS_ST,a.BL25_data_SS_ST,a.BL26_data_SS_ST,a.BL27_data_SS_ST,b.st1_prmt_status_p45,c.beam_current,c.beam_energy from INDUS2_BLFE.dbo.main_BLFE_status a inner join INDUS2_MSIS.dbo.main_MSIS_status b on a.logtime=b.logtime inner join INDUS2_BDS.dbo.DCCT c on b.logtime=c.logtime ORDER BY c.logtime DESC ";

    stmt.executeQuery(sql);
    rs = stmt.getResultSet();

    while (rs.next()) {
      for (int j = 2; j < 29; j++) {
        if (!status.equals(rs.getInt(j)))
          arr[i][j] = rs.getInt(j);
      }
    }
  } catch (Exception e) {
    System.out.println("\nException in  Bean " + e);
  } finally {
    closeConnection(stmt, rs, con);
  }

  return arr;
}

But the output is coming as

[[I@553763.

How to resolve it??

Answer 1

The print statement is printing the string representation of the exception. To print a meaningful (human meaningful that is) string, you will need to replace this: System.out.println("\\nException in Bean " + e); with this: System.out.println("\\nException in Bean " + e.getMessage()); .

For more information, you can you e.printStackTrace() to print the stack trace for the exception.

Answer 2

Your logic is wrong. You are comparing an array to an integer.

Change it to :

  for (int j = 2; j < 29; j++) {
    if (rs.getInt(j)==1)
      arr[i][j] = rs.getInt(j);
  }

As to the output you see, you should print Arrays.deepToString(arr) . Printing the array as you currently do calls Object 's default toString() implementation, which doesn't display the content of the array.

Answer 3

This code can help you to achieve what you want. You will need to check for columnTypes in if block.

// Get resultset metadata
ResultSetMetaData meta = rs.getMetaData();

// Get count of columns
int columnCount = meta.getColumnCount();

// Iterate over all columns
for (int i = 0; i < columnCount; i++) { 
    // Get name of column
    String columnName = meta.getColumnName(i + 1);
    if (meta.getColumnType(i+1) == Types.INTEGER && rs.getInt(i+1)==1) {
        // if columnt type is integer and value is 1 print name and value
        System.out.println("Columnname:" + columnName);
        System.out.println("Columnvalue:" + rs.getInt(i+1)); 
    }
}