ResultSetからJTableを生成する最も単純なコード
私は一日中グーグルで運がなかった。 OKボタンを押した後、getnPrintAllData()メソッドを呼び出します。したがって、コードは次のとおりです。
public class DatabaseSQLiteConnection {
Connection conn = null;
PreparedStatement statement = null;
ResultSet res = null;
public DatabaseSQLiteConnection(){
try{
Class.forName("org.sqlite.JDBC");
conn = DriverManager.getConnection("jdbc:sqlite:test.sqlite");
statement = conn.prepareStatement("SELECT * from product_info;");
}
catch(Exception e){
e.printStackTrace();
}
}
public void getnPrintAllData(){
String name, supplier, id;
DefaultTableModel dtm = new DefaultTableModel();
Window gui = new Window(); //My JPanel class
try{
res = statement.executeQuery();
testResultSet(res);
ResultSetMetaData meta = res.getMetaData();
int numberOfColumns = meta.getColumnCount();
while (res.next())
{
Object [] rowData = new Object[numberOfColumns];
for (int i = 0; i < rowData.length; ++i)
{
rowData[i] = res.getObject(i+1);
}
dtm.addRow(rowData);
}
gui.jTable1.setModel(dtm);
dtm.fireTableDataChanged();
//////////////////////////
}
catch(Exception e){
System.err.println(e);
e.printStackTrace();
}
finally{
try{
res.close();
statement.close();
conn.close();
}
catch(Exception e){
e.printStackTrace();
}
}
}
public void testResultSet(ResultSet res){
try{
while(res.next()){
System.out.println("Product ID: "+ res.getInt("product_id"));
System.out.println("Product name: "+ res.getString("product_name"));
System.out.println("Supplier: "+ res.getString("supplier"));
}
}
catch(Exception e){
e.printStackTrace();
}
}
}
testResultSet()メソッドは正常に機能しています。今、それが機能するようにコードを変更する方法、またはDefaultTableModelをResultSetから作成する最も簡単なコードは何ですか？前もって感謝します。
編集：Java.lang.IllegalStateException: SQLite JDBC: inconsistent internal stateエラーを受け取っています。
ResultSetのインスタンスからモデルを構築する最も簡単な方法は、次のとおりだと思います。
public static void main(String[] args) throws Exception {
// The Connection is obtained
ResultSet rs = stmt.executeQuery("select * from product_info");
// It creates and displays the table
JTable table = new JTable(buildTableModel(rs));
// Closes the Connection
JOptionPane.showMessageDialog(null, new JScrollPane(table));
}
メソッドbuildTableModel：
public static DefaultTableModel buildTableModel(ResultSet rs)
throws SQLException {
ResultSetMetaData metaData = rs.getMetaData();
// names of columns
Vector<String> columnNames = new Vector<String>();
int columnCount = metaData.getColumnCount();
for (int column = 1; column <= columnCount; column++) {
columnNames.add(metaData.getColumnName(column));
}
// data of the table
Vector<Vector<Object>> data = new Vector<Vector<Object>>();
while (rs.next()) {
Vector<Object> vector = new Vector<Object>();
for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
vector.add(rs.getObject(columnIndex));
}
data.add(vector);
}
return new DefaultTableModel(data, columnNames);
}
UPDATE
javax.swing.SwingWorker を使用しますか？ try-with-resources ステートメントを使用しますか？
public class GUI extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new GUI().setVisible(true);
}
});
}
private final JButton button;
private final JTable table;
private final DefaultTableModel tableModel = new DefaultTableModel();
public GUI() throws HeadlessException {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
table = new JTable(tableModel);
add(new JScrollPane(table), BorderLayout.CENTER);
button = new JButton("Load Data");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() throws Exception {
loadData();
return null;
}
}.execute();
}
});
add(button, BorderLayout.PAGE_START);
setSize(640, 480);
}
private void loadData() {
LOG.info("START loadData method");
button.setEnabled(false);
try (Connection conn = DriverManager.getConnection(url, usr, pwd);
Statement stmt = conn.createStatement()) {
ResultSet rs = stmt.executeQuery("select * from customer");
ResultSetMetaData metaData = rs.getMetaData();
// Names of columns
Vector<String> columnNames = new Vector<String>();
int columnCount = metaData.getColumnCount();
for (int i = 1; i <= columnCount; i++) {
columnNames.add(metaData.getColumnName(i));
}
// Data of the table
Vector<Vector<Object>> data = new Vector<Vector<Object>>();
while (rs.next()) {
Vector<Object> vector = new Vector<Object>();
for (int i = 1; i <= columnCount; i++) {
vector.add(rs.getObject(i));
}
data.add(vector);
}
tableModel.setDataVector(data, columnNames);
} catch (Exception e) {
LOG.log(Level.SEVERE, "Exception in Load Data", e);
}
button.setEnabled(true);
LOG.info("END loadData method");
}
}
これは、次のようなメソッドを使用して、ResultSetでテーブルを作成する最も簡単な方法だと思います
FillTable(MyTable, "select * Customers;");
そして、非常に簡単な方法は
public void FillTable(JTable table, String Query)
{
try
{
CreateConnection();
Statement stat = conn.createStatement();
ResultSet rs = stat.executeQuery(Query);
//To remove previously added rows
while(table.getRowCount() > 0)
{
((DefaultTableModel) table.getModel()).removeRow(0);
}
int columns = rs.getMetaData().getColumnCount();
while(rs.next())
{
Object[] row = new Object[columns];
for (int i = 1; i <= columns; i++)
{
row[i - 1] = rs.getObject(i);
}
((DefaultTableModel) table.getModel()).insertRow(rs.getRow()-1,row);
}
rs.close();
stat.close();
conn.close();
}
catch(InstantiationException | IllegalAccessException | SQLException e)
{
}
}
これは、外部ライブラリを使用せずに、ResultSetからJTableを生成する最も簡単な方法であると確信しています。このメソッドにコメントを含めました。
public void resultSetToTableModel(ResultSet rs, JTable table) throws SQLException{
//Create new table model
DefaultTableModel tableModel = new DefaultTableModel();
//Retrieve meta data from ResultSet
ResultSetMetaData metaData = rs.getMetaData();
//Get number of columns from meta data
int columnCount = metaData.getColumnCount();
//Get all column names from meta data and add columns to table model
for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++){
tableModel.addColumn(metaData.getColumnLabel(columnIndex));
}
//Create array of Objects with size of column count from meta data
Object[] row = new Object[columnCount];
//Scroll through result set
while (rs.next()){
//Get object from column with specific index of result set to array of objects
for (int i = 0; i < columnCount; i++){
row[i] = rs.getObject(i+1);
}
//Now add row to table model with that array of objects as an argument
tableModel.addRow(row);
}
//Now add that table model to your table and you are done :D
table.setModel(tableModel);
}
クラスRowは、データベースから1行を処理します。
UIを埋めるUpdateTaskの完全な実装。
import Java.sql.ResultSet;
import Java.sql.SQLException;
import Java.util.ArrayList;
import Java.util.List;
import javax.swing.JTable;
import javax.swing.SwingWorker;
public class JTableUpdateTask extends SwingWorker<JTable, Row> {
JTable table = null;
ResultSet resultSet = null;
public JTableUpdateTask(JTable table, ResultSet rs) {
this.table = table;
this.resultSet = rs;
}
@Override
protected JTable doInBackground() throws Exception {
List<Row> rows = new ArrayList<Row>();
Object[] values = new Object[6];
while (resultSet.next()) {
values = new Object[6];
values[0] = resultSet.getString("id");
values[1] = resultSet.getString("student_name");
values[2] = resultSet.getString("street");
values[3] = resultSet.getString("city");
values[4] = resultSet.getString("state");
values[5] = resultSet.getString("zipcode");
Row row = new Row(values);
rows.add(row);
}
process(rows);
return this.table;
}
protected void process(List<Row> chunks) {
ResultSetTableModel tableModel = (this.table.getModel() instanceof ResultSetTableModel ? (ResultSetTableModel) this.table.getModel() : null);
if (tableModel == null) {
try {
tableModel = new ResultSetTableModel(this.resultSet.getMetaData(), chunks);
} catch (SQLException e) {
e.printStackTrace();
}
this.table.setModel(tableModel);
} else {
tableModel.getRows().addAll(chunks);
}
tableModel.fireTableDataChanged();
}
}
テーブルモデル：
import Java.sql.ResultSetMetaData;
import Java.sql.SQLException;
import Java.util.ArrayList;
import Java.util.List;
import javax.swing.table.AbstractTableModel;
/**
* Simple wrapper around Object[] representing a row from the ResultSet.
*/
class Row {
private final Object[] values;
public Row(Object[] values) {
this.values = values;
}
public int getSize() {
return values.length;
}
public Object getValue(int i) {
return values[i];
}
}
// TableModel implementation that will be populated by SwingWorker.
public class ResultSetTableModel extends AbstractTableModel {
private final ResultSetMetaData rsmd;
private List<Row> rows;
public ResultSetTableModel(ResultSetMetaData rsmd, List<Row> rows) {
this.rsmd = rsmd;
if (rows != null) {
this.rows = rows;
} else {
this.rows = new ArrayList<Row>();
}
}
public int getRowCount() {
return rows.size();
}
public int getColumnCount() {
try {
return rsmd.getColumnCount();
} catch (SQLException e) {
e.printStackTrace();
}
return 0;
}
public Object getValue(int row, int column) {
return rows.get(row).getValue(column);
}
public String getColumnName(int col) {
try {
return rsmd.getColumnName(col + 1);
} catch (SQLException e) {
e.printStackTrace();
}
return "";
}
public Class<?> getColumnClass(int col) {
String className = "";
try {
className = rsmd.getColumnClassName(col);
} catch (SQLException e) {
e.printStackTrace();
}
return className.getClass();
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
if(rowIndex > rows.size()){
return null;
}
return rows.get(rowIndex).getValue(columnIndex);
}
public List<Row> getRows() {
return this.rows;
}
public void setRows(List<Row> rows) {
this.rows = rows;
}
}
UIを構築し、データベース接続を行うメインアプリケーション
import Java.awt.BorderLayout;
import Java.awt.Dimension;
import Java.awt.event.ActionEvent;
import Java.awt.event.ActionListener;
import Java.sql.Connection;
import Java.sql.DriverManager;
import Java.sql.PreparedStatement;
import Java.sql.ResultSet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTable;
public class MainApp {
static Connection conn = null;
static void init(final ResultSet rs) {
JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
final JTable table = new JTable();
table.setPreferredSize(new Dimension(300,300));
table.setMinimumSize(new Dimension(300,300));
table.setMaximumSize(new Dimension(300,300));
frame.add(table, BorderLayout.CENTER);
JButton button = new JButton("Start Loading");
button.setPreferredSize(new Dimension(30,30));
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
JTableUpdateTask jTableUpdateTask = new JTableUpdateTask(table, rs);
jTableUpdateTask.execute();
}
});
frame.add(button, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
String url = "jdbc:mysql://localhost:3306/test";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "root";
try {
Class.forName(driver).newInstance();
conn = DriverManager.getConnection(url, userName, password);
PreparedStatement pstmt = conn.prepareStatement("Select id, student_name, street, city, state,zipcode from student");
ResultSet rs = pstmt.executeQuery();
init(rs);
} catch (Exception e) {
e.printStackTrace();
}
}
}
JTableコンストラクタは、データ用の2次元オブジェクト配列と、列名用の文字列配列の2つの引数を受け入れます。
例えば：
import Java.awt.BorderLayout;
import Java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class Test6 extends JFrame {
public Test6(){
this.setSize(300,300);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Mpanel m = new Mpanel();
this.add(m,BorderLayout.CENTER);
}
class Mpanel extends JPanel {
JTable mTable;
private Object[][] cells = {{"Vivek",10.00},{"Vishal",20.00}};
private String[] columnNames = { "Planet", "Radius" };
JScrollPane mScroll;
public Mpanel(){
this.setSize(150,150);
this.setComponent();
}
public void setComponent(){
mTable = new JTable(cells,columnNames);
mTable.setAutoCreateRowSorter(true);
mScroll = new JScrollPane(mTable);
this.add(mScroll);
}
}
public static void main(String[] args){
new Test6().setVisible(true);
}
}
これは私のアプローチです：
String[] columnNames = {"id", "Nome", "Sobrenome","Email"};
List<Student> students = _repo.getAll();
Object[][] data = new Object[students.size()][4];
int index = 0;
for(Student s : students) {
data[index][0] = s.getId();
data[index][1] = s.getFirstName();
data[index][2] = s.getLastName();
data[index][3] = s.getEmail();
index++;
}
DefaultTableModel model = new DefaultTableModel(data, columnNames);
table = new JTable(model);
このリンクをクリックして、rs2xmlというJarをダウンロードする必要があります rs2xml.jar それをプロジェクトライブラリに追加してからインポートします
import net.proteanit.sql.DbUtils;
サンプルとしてそうするための方法だけを準備します
private void Update_table(){
try{
// fetch a connection
connection = your_connection_class_name_here.getInstance().getConnection();
if (connection != null) {
String sql="select name,description from sell_mode";
pst=connection.prepareStatement(sql);
rs=pst.executeQuery();
your_table_name_for_populating_your_Data.setModel(DbUtils.resultSetToTableModel(rs));
}
}
catch(IOException | SQLException | PropertyVetoException e){
JOptionPane.showMessageDialog(null,e);
}
finally {
if (rs!= null) try { rs.close(); } catch (SQLException e) {}
if (pst != null) try { pst.close(); } catch (SQLException e) {}
if (connection != null) try { connection.close(); } catch (SQLException e) {}
}
}
これがもっと役立つことを願っています
ここに行く Java tips weblog
次に、プロジェクトに入力します：listtabelmodel.Javaおよびrowtablemodel.Javaは、次のコードで別のクラスを追加します。
enter code here
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package comp;
import Java.awt.*;
import Java.sql.*;
import Java.util.*;
import javax.swing.*;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.table.*;
public class TableFromDatabase extends JPanel {
private Connection conexao = null;
public TableFromDatabase() {
Vector columnNames = new Vector();
Vector data = new Vector();
try {
// Connect to an Access Database
conexao = DriverManager.getConnection("jdbc:mysql://" + "localhost"
+ ":3306/yourdatabase", "root", "password");
// Read data from a table
String sql = "select * from tb_something";
Statement stmt = conexao.createStatement();
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++) {
columnNames.addElement(md.getColumnName(i));
}
// Get row data
while (rs.next()) {
Vector row = new Vector(columns);
for (int i = 1; i <= columns; i++) {
row.addElement(rs.getObject(i));
}
data.addElement(row);
}
rs.close();
stmt.close();
conexao.close();
} catch (Exception e) {
System.out.println(e);
}
// Create table with database data
JTable table = new JTable(data, columnNames) {
public Class getColumnClass(int column) {
for (int row = 0; row < getRowCount(); row++) {
Object o = getValueAt(row, column);
if (o != null) {
return o.getClass();
}
}
return Object.class;
}
};
JScrollPane scrollPane = new JScrollPane(table);
add(scrollPane);
JPanel buttonPanel = new JPanel();
add(buttonPanel, BorderLayout.SOUTH);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("any");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
TableFromDatabase newContentPane = new TableFromDatabase();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
}
});
}
}
次に、このクラスをjframeにドラッグします。
非推奨ですが、動作します.........
すべての要因を考慮すると、モジュラープログラミングを使用したコードアーキテクチャに関しては非常にうまく機能し、コードがより単純になります。簡単に書く
getData() function @returns a 2D array of the data from the database.
この機能をJTabel（）コンストラクターのコンストラクターに渡します。
JTabel myTable = new JTable(getData(),columnsArray);
この場合、2番目の引数：columnsArrayは、列名を持つ単一次元配列です。
String[] columns = {{"ID","DataOfBirth","Age","Grade","Marks","RegNumber"}};
jTableオブジェクトをJScrollPaneに渡すと、ScrollPaneをもちろんコンテナーに追加した直後に完了します。
JScrollPane scrollPane = new JScrollPane(myTable);
JFrame myFrame = new JFrame();
myFrame.add(scrollPane);
これは、後でJTableに渡されるデータをデータベースに照会するサンプル関数getData（）です。
public String[][] getRecords() {
try (Connection conect = DriverManager.getConnection("jdbc:mysql://localhost:3306/online_students_registration", "root", "")) {
Statement stm = conect.createStatement();
String SELECT_QUERY = "SELECT COUNT(*) FROM medicalrecords ;";
ResultSet cursor = stm.executeQuery(SELECT_QUERY);
while (cursor.next()) {
rows = cursor.getInt("COUNT(*)");
System.out.println("Table will have " + rows + " Rows");
}
System.err.println("Contacts row count is obtained!!");
if (rows < 1) {
JOptionPane.showMessageDialog(null, "There is NO DATA");
//contactsRowsCount = 1;
//System.out.println("Table rows succefully reset to " + contactsRowsCount + " Rows");
dataValues = new String[1][8];
//dataValues[1][5] = "No Values";
for (int i = 0; i < 1; i++) {
for (int j = 0; j < 8; j++) {
if (j == 0) {
dataValues[i][j] = "No Details Available";
System.out.println("" + dataValues);
} else {
dataValues[i][j] = "...";
System.out.println("Contacts" + dataValues[i][j]);
}
}
}
System.out.println("Return statement is being executed on 0 rows ");
//return doctoredDataValues;
} else if (rows > 0) {
System.out.println("obtain contacts code is being run under " + rows + " Rows");
dataValues = new String[rows][8]; //declare array for contacts table data
System.out.println("[ Line 1584 ]The dataValues object for the JTable succefully set");
String SELECT_QUERY_CONTACT = "SELECT * FROM medicalrecords; ";
//OBTAIN CONTACTS FROM DB WITH REGARD TO CONTACT CATEGORY SPECIFIED
ResultSet contactsTableCursor = stm.executeQuery(SELECT_QUERY_CONTACT);
//use iterator-algorithm to insert values into the JTable
for (int i = 0; contactsTableCursor.next() && i < rows; i++) {
for (int j = 0; j < 8; j++) {
dataValues[i][j] = contactsTableCursor.getString(j + 1);
System.out.println("Contacts" + dataValues[i][j]);
}
}
}
JOptionPane.showMessageDialog(null, "Medical Details Added Succefully!!");
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, "Unable to Obtain contacts:Server is Offline(LINE 1568)" + e.getMessage());
}
return dataValues;
}