src/main/java/net/jaekl/squelch/stmt/Select.java

   1 package net.jaekl.squelch.stmt;
   2
   3 import java.io.IOException;
   4 import java.io.PrintWriter;
   5 import java.sql.Connection;
   6 import java.sql.PreparedStatement;
   7 import java.sql.ResultSet;
   8 import java.sql.ResultSetMetaData;
   9 import java.sql.SQLException;
  10 import java.util.Locale;
  11
  12 import net.jaekl.squelch.sql.Column;
  13
  14 public class Select extends Query {
  15
  16         @Override
  17         public boolean handles(String line) {
  18                 if (null == line) {
  19                         return false;
  20                 }
  21
  22                 String s = line.trim().toUpperCase(Locale.CANADA);
  23                 return (s.startsWith("SELECT "));
  24         }
  25
  26         @Override
  27         public int exec(Connection conn, PrintWriter pw, String line) throws IOException, SQLException
  28         {
  29                 int rowCount = 0;
  30
  31                 try (PreparedStatement ps = conn.prepareStatement(line))
  32                 {
  33                         try (ResultSet rs = ps.executeQuery())
  34                         {
  35                                 rowCount = printFormatted(pw, rs);
  36
  37                         }
  38                 }
  39                 return rowCount;
  40         }
  41
  42         private Column[] getColumns(ResultSetMetaData metaData)
  43                         throws SQLException, ClassNotFoundException
  44         {
  45                 int colCount = metaData.getColumnCount();
  46
  47                 Column cols[] = new Column[colCount];
  48                 for (int idx = 1; idx <= colCount; ++idx) {
  49                         String label = metaData.getColumnLabel(idx);
  50                         Class<?> clazz = Class.forName(metaData.getColumnTypeName(idx));
  51                         int width = metaData.getColumnDisplaySize(idx);
  52                         cols[idx] = new Column(label, clazz, width);
  53                 }
  54
  55                 return cols;
  56         }
  57
  58         private int printFormatted(PrintWriter pw, ResultSet rs) throws IOException, SQLException
  59         {
  60                 try {
  61                         ResultSetMetaData metaData = rs.getMetaData();
  62                         int rowCount = 0;
  63                         Column[] cols = getColumns(metaData);
  64                         StringBuilder sb = new StringBuilder();
  65                         sb.append("----------------------------------\n");
  66                         for (int idx = 1; idx <= cols.length; ++idx) {
  67                                 sb.append("|" + cols[idx - 1].getLabel());
  68                         }
  69                         sb.append("|\n");
  70                         String header = sb.toString();
  71
  72                         while (rs.next()) {
  73                                 if (null != header) {
  74                                         pw.print(header);
  75                                         header = null;
  76                                 }
  77
  78                                 for (int idx = 1; idx <= cols.length; ++idx) {
  79                                         pw.print("|" + rs.getObject(idx));
  80                                 }
  81                                 pw.println("|");
  82                         }
  83                         if (rowCount > 0) {
  84                                 pw.println("----------------------------------");
  85                         }
  86                         pw.println("" + rowCount + " row(s) returned.");
  87
  88                         return rowCount;
  89                 }
  90                 catch (ClassNotFoundException exc) {
  91                         throw new SQLException(exc);
  92                 }
  93         }
  94 }