求救!
各位大侠,我怎样把数据库中数据写到Jtable中?
for(int i=0;i<y;i++)
{ for(int j=0;j<x;j++)
{
a[i][j]=rs.getString(j+1);
}
rs.next();
}
这个代码有问题,怎么改呢?
各位大侠,我怎样把数据库中数据写到Jtable中?
for(int i=0;i<y;i++)
{ for(int j=0;j<x;j++)
{
a[i][j]=rs.getString(j+1);
}
rs.next();
}
这个代码有问题,怎么改呢?
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初始时,可以用构造函数直接传数组或是VECTOR
import java.util.Vector;
import java.sql.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.event.TableModelEvent;public class JDBCAdapter extends AbstractTableModel {
Connection connection;
Statement statement;
ResultSet resultSet;
String[] columnNames = {};
Vector rows = new Vector();
ResultSetMetaData metaData; public JDBCAdapter(String url, String driverName,
String user, String passwd) {
try {
Class.forName(driverName);
System.out.println("Opening db connection"); connection = DriverManager.getConnection(url, user, passwd);
statement = connection.createStatement();
}
catch (ClassNotFoundException ex) {
System.err.println("Cannot find the database driver classes.");
System.err.println(ex);
}
catch (SQLException ex) {
System.err.println("Cannot connect to this database.");
System.err.println(ex);
}
} public void executeQuery(String query) {
if (connection == null || statement == null) {
System.err.println("There is no database to execute the query.");
return;
}
try {
resultSet = statement.executeQuery(query);
metaData = resultSet.getMetaData(); int numberOfColumns = metaData.getColumnCount();
columnNames = new String[numberOfColumns];
// Get the column names and cache them.
// Then we can close the connection.
for(int column = 0; column < numberOfColumns; column++) {
columnNames[column] = metaData.getColumnLabel(column+1);
} // Get all rows.
rows = new Vector();
while (resultSet.next()) {
Vector newRow = new Vector();
for (int i = 1; i <= getColumnCount(); i++) {
newRow.addElement(resultSet.getObject(i));
}
rows.addElement(newRow);
}
// close(); Need to copy the metaData, bug in jdbc:odbc driver.
fireTableChanged(null); // Tell the listeners a new table has arrived.
}
catch (SQLException ex) {
System.err.println(ex);
}
} public void close() throws SQLException {
System.out.println("Closing db connection");
resultSet.close();
statement.close();
connection.close();
} protected void finalize() throws Throwable {
close();
super.finalize();
} //////////////////////////////////////////////////////////////////////////
//
// Implementation of the TableModel Interface
//
////////////////////////////////////////////////////////////////////////// // MetaData public String getColumnName(int column) {
if (columnNames[column] != null) {
return columnNames[column];
} else {
return "";
}
} public Class getColumnClass(int column) {
int type;
try {
type = metaData.getColumnType(column+1);
}
catch (SQLException e) {
return super.getColumnClass(column);
} switch(type) {
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
return String.class; case Types.BIT:
return Boolean.class; case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
return Integer.class; case Types.BIGINT:
return Long.class; case Types.FLOAT:
case Types.DOUBLE:
return Double.class; case Types.DATE:
return java.sql.Date.class; default:
return Object.class;
}
} public boolean isCellEditable(int row, int column) {
try {
return metaData.isWritable(column+1);
}
catch (SQLException e) {
return false;
}
} public int getColumnCount() {
return columnNames.length;
} // Data methods public int getRowCount() {
return rows.size();
} public Object getValueAt(int aRow, int aColumn) {
Vector row = (Vector)rows.elementAt(aRow);
return row.elementAt(aColumn);
} public String dbRepresentation(int column, Object value) {
int type; if (value == null) {
return "null";
} try {
type = metaData.getColumnType(column+1);
}
catch (SQLException e) {
return value.toString();
} switch(type) {
case Types.INTEGER:
case Types.DOUBLE:
case Types.FLOAT:
return value.toString();
case Types.BIT:
return ((Boolean)value).booleanValue() ? "1" : "0";
case Types.DATE:
return value.toString(); // This will need some conversion.
default:
return "\""+value.toString()+"\"";
} } public void setValueAt(Object value, int row, int column) {
try {
String tableName = metaData.getTableName(column+1);
// Some of the drivers seem buggy, tableName should not be null.
if (tableName == null) {
System.out.println("Table name returned null.");
}
String columnName = getColumnName(column);
String query =
"update "+tableName+
" set "+columnName+" = "+dbRepresentation(column, value)+
" where ";
// We don't have a model of the schema so we don't know the
// primary keys or which columns to lock on. To demonstrate
// that editing is possible, we'll just lock on everything.
for(int col = 0; col<getColumnCount(); col++) {
String colName = getColumnName(col);
if (colName.equals("")) {
continue;
}
if (col != 0) {
query = query + " and ";
}
query = query + colName +" = "+
dbRepresentation(col, getValueAt(row, col));
}
System.out.println(query);
System.out.println("Not sending update to database");
// statement.executeQuery(query);
}
catch (SQLException e) {
// e.printStackTrace();
System.err.println("Update failed");
}
Vector dataRow = (Vector)rows.elementAt(row);
dataRow.setElementAt(value, column); }
}