创建一个JDBC表格模型
创建一个JDBC表格模型
代码语言：javascript复制import javax.swing.*;
import javax.swing.table.*;
import java.sql.*;
import java.util.*;
/** an immutable table model built from getting
metadata about a table in a jdbc database
*/
public class JDBCTableModel extends AbstractTableModel {
Object[][] contents;
String[] columnNames;
Class[] columnClasses;
public JDBCTableModel (Connection conn,
String tableName)
throws SQLException {
super();
getTableContents (conn, tableName);
}
protected void getTableContents (Connection conn,
String tableName)
throws SQLException {
// get metadata: what columns exist and what
// types (classes) are they?
DatabaseMetaData meta = conn.getMetaData();
System.out.println ("got meta = " meta);
ResultSet results =
meta.getColumns (null, null, tableName, null) ;
System.out.println ("got column results");
ArrayList colNamesList = new ArrayList();
ArrayList colClassesList = new ArrayList();
while (results.next()) {
colNamesList.add (results.getString ("COLUMN_NAME"));
System.out.println ("name: "
results.getString ("COLUMN_NAME"));
int dbType = results.getInt ("DATA_TYPE");
switch (dbType) {
case Types.INTEGER:
colClassesList.add (Integer.class); break;
case Types.FLOAT:
colClassesList.add (Float.class); break;
case Types.DOUBLE:
case Types.REAL:
colClassesList.add (Double.class); break;
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP:
colClassesList.add (java.sql.Date.class); break;
default:
colClassesList.add (String.class); break;
};
System.out.println ("type: "
results.getInt ("DATA_TYPE"));
}
columnNames = new String [colNamesList.size()];
colNamesList.toArray (columnNames);
columnClasses = new Class [colClassesList.size()];
colClassesList.toArray (columnClasses);
// get all data from table and put into
// contents array
Statement statement =
conn.createStatement ();
results = statement.executeQuery ("SELECT * FROM "
tableName);
ArrayList rowList = new ArrayList();
while (results.next()) {
ArrayList cellList = new ArrayList();
for (int i = 0; i<columnClasses.length; i ) {
Object cellValue = null;
if (columnClasses[i] == String.class)
cellValue = results.getString (columnNames[i]);
else if (columnClasses[i] == Integer.class)
cellValue = new Integer (
results.getInt (columnNames[i]));
else if (columnClasses[i] == Float.class)
cellValue = new Float (
results.getInt (columnNames[i]));
else if (columnClasses[i] == Double.class)
cellValue = new Double (
results.getDouble (columnNames[i]));
else if (columnClasses[i] == java.sql.Date.class)
cellValue = results.getDate (columnNames[i]);
else
System.out.println ("Can't assign "
columnNames[i]);
cellList.add (cellValue);
}// for
Object[] cells = cellList.toArray();
rowList.add (cells);
} // while
// finally create contents two-dim array
contents = new Object[rowList.size()] [];
for (int i=0; i<contents.length; i )
contents[i] = (Object []) rowList.get (i);
System.out.println ("Created model with "
contents.length " rows");
// close stuff
results.close();
statement.close();
}
// AbstractTableModel methods
public int getRowCount() {
return contents.length;
}
public int getColumnCount() {
if (contents.length == 0)
return 0;
else
return contents[0].length;
}
public Object getValueAt (int row, int column) {
return contents [row][column];
}
// overrides methods for which AbstractTableModel
// has trivial implementations
public Class getColumnClass (int col) {
return columnClasses [col];
}
public String getColumnName (int col) {
return columnNames [col];
}
}测试基于JDBC的表
代码语言：javascript复制import javax.swing.*;
import javax.swing.table.*;
import java.sql.*;
import java.util.*;
import java.io.*;
public class TestJDBCTable {
public static void main (String[] args) {
try {
/*
driver, url, user, and pass can be passed in as
system properties "jdbctable.driver",
"jdbctable.url", "jdbctable.user", and
"jdbctable.pass", or specified in a file
called "jdbctable.properties" in current
directory
*/
Properties testProps = new Properties();
String ddriver = System.getProperty ("jdbctable.driver");
String durl = System.getProperty ("jdbctable.url");
String duser = System.getProperty ("jdbctable.user");
String dpass = System.getProperty ("jdbctable.pass");
if (ddriver != null)
testProps.setProperty ("jdbctable.driver", ddriver);
if (durl != null)
testProps.setProperty ("jdbctable.url", durl);
if (duser != null)
testProps.setProperty ("jdbctable.user", duser);
if (dpass != null)
testProps.setProperty ("jdbctable.pass", dpass);
try {
testProps.load (new FileInputStream (
new File ("jdbctable.properties")));
} catch (Exception e) {} // ignore FNF, etc.
System.out.println ("Test Properties:");
testProps.list (System.out);
// now get a connection
// note care to replace nulls with empty strings
Class.forName(testProps.getProperty
("jdbctable.driver")).newInstance();
String url = testProps.getProperty ("jdbctable.url");
url = ((url == null) ? "" : url);
String user = testProps.getProperty ("jdbctable.user");
user = ((user == null) ? "" : user);
String pass = testProps.getProperty ("jdbctable.pass");
pass = ((pass == null) ? "" : pass);
Connection conn =
DriverManager.getConnection (url, user, pass);
// create db table to use
String tableName = createSampleTable(conn);
// get a model for this db table and add to a JTable
TableModel mod =
new JDBCTableModel (conn, tableName);
JTable jtable = new JTable (mod);
JScrollPane scroller =
new JScrollPane (jtable,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
JFrame frame = new JFrame ("JDBCTableModel demo");
frame.getContentPane().add (scroller);
frame.pack();
frame.setVisible (true);
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static String createSampleTable (Connection conn)
throws SQLException {
Statement statement = conn.createStatement();
// drop table if it exists
try {
statement.execute ("DROP TABLE EMPLOYEES");
} catch (SQLException sqle) {
sqle.printStackTrace(); // if table !exists
}
statement.execute ("CREATE TABLE EMPLOYEES "
"(Name CHAR(20), Title CHAR(30), Salary INT)");
statement.execute ("INSERT INTO EMPLOYEES VALUES "
"('Jill', 'CEO', 200000 )");
statement.execute ("INSERT INTO EMPLOYEES VALUES "
"('Bob', 'VP', 195000 )");
statement.execute ("INSERT INTO EMPLOYEES VALUES "
"('Omar', 'VP', 190000 )");
statement.execute ("INSERT INTO EMPLOYEES VALUES "
"('Amy', 'Software Engineer', 50000 )");
statement.execute ("INSERT INTO EMPLOYEES VALUES "
"('Greg', 'Software Engineer', 45000 )");
statement.close();
return "EMPLOYEES";
}
}
