1

我有三个文件，TopicData、TopicView、TopicTableModel。我的程序使用数据库中的值显示一个表。现在，当我单击一行时，会打印该行的索引。我想修改代码，以便打印数据库中的 topicID。topicID 的值存储在 ArrayList 中但不显示在表格中，所以我不能使用 JTable.getValueAt()。

请告知如何修改我的代码。提前致谢。

更多信息：

  1. TopicData 从数据库中获取数据并将其存储在 ArrayList 中。

  2. 然后将 ArrayList 传递给 TopicTableModel，在该模型中数据适合在 JTable 中显示。

  3. TopicView 创建一个 JTable 并接受 TopicTableModel 来生成 JTable。

主题数据.java

public class TopicData {
int id;
String name; 
String date; 
String category;
String user;

public TopicData(){
}

public TopicData(int id, String name, String date, String category, String user) {
    this.id = id;
    this.name = name;
    this.date = date;
    this.category = category;
    this.user = user;
}



public TopicData(String name, String date, String category, String user) {
    this.name = name;
    this.date = date;
    this.category = category;
    this.user = user;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getDate() {
    return date;
}

public void setDate(String date) {
    this.date = date;
}

public String getCategory() {
    return category;
}

public void setCategory(String category) {
    this.category = category;
}

public String getUser() {
    return user;
}

public void setUser(String user) {
    this.user = user;
}


public ArrayList<TopicData> getTopicList(){
    ArrayList<TopicData> topicList = new ArrayList<TopicData>();
    ResultSet rs = null;
    DBController db = new DBController();
    db.setUp("myDatabase");
    String dbQuery = "SELECT topicID, topicName, topicDate, topicCategory, topicUser FROM topicTable ORDER BY topicDate";

    rs = db.readRequest(dbQuery);

    try{
        while(rs.next()){
            int id = rs.getInt("topicID");
            String name = rs.getString("topicName"); 
            String date = rs.getString("topicDate") ; 
            String category = rs.getString("topicCategory");
            String user = rs.getString("topicUser");

            TopicData topic = new TopicData (id, name, date, category, user);
            topicList.add(topic);
        }
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    db.terminate();
    return topicList;
}

TopicTableModel.java

public class TopicTableModel extends AbstractTableModel {

private static final long serialVersionUID = 1L;
private int rowCount, colCount;
private String[] columnNames = {"Name", "Date", "User"};
private Object [][] data;

public TopicTableModel(ArrayList<TopicData> listOfObjects) {
    rowCount = listOfObjects.size();
    colCount = columnNames.length;
    data = new Object[rowCount][colCount];

    for (int i = 0; i < rowCount; i++) {
        //Copy an ArrayList element to an instance of MyObject
        TopicData topic = (listOfObjects.get(i)); 
        data[i][0] = topic.getName();            
        data[i][1] = topic.getDate();
        data[i][2] = topic.getUser();
    }              
} 

@Override
public int getColumnCount() {
    // TODO Auto-generated method stub
    return colCount;
}

@Override
public int getRowCount() {
    // TODO Auto-generated method stub
    return rowCount;
}

@Override
public String getColumnName(int col) {
    return columnNames[col];
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    // TODO Auto-generated method stub
    return data[rowIndex][columnIndex];
}

@Override
public boolean isCellEditable(int rowIndex, int colIndex) {
    return false; //Disallow the editing of any cell
}

}

主题视图.java

private JTable getTable() {
    if (table == null) {
        TopicData topic= new TopicData();
        TopicTableModel tableModel = new TopicTableModel(topic.getTopicList());
        table = new JTable(tableModel);

        table.setShowGrid(false);
        table.setFillsViewportHeight(true);
        table.setBounds(173, 87, 456, 263);
        table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        table.getTableHeader().setReorderingAllowed(false);
        table.getTableHeader().setResizingAllowed(false);
        table.getColumnModel().getColumn(0).setPreferredWidth(500);

        ListSelectionModel rowSM = table.getSelectionModel();
        rowSM.addListSelectionListener(new ListSelectionListener() {
            public void valueChanged(ListSelectionEvent e) {
                //Ignore extra messages.
                if (e.getValueIsAdjusting()) return;

                ListSelectionModel lsm = (ListSelectionModel)e.getSource();
                if (lsm.isSelectionEmpty()) {
                    System.out.println("No rows are selected.");
                } 
                else {
                    int selectedRow = lsm.getMinSelectionIndex();
                    System.out.println("Row " + selectedRow + " is now selected.");
                }
            }
        });
    }
    return table;
}
4

2 回答 2

4

你正在艰难地做这件事。无需将 TopicData 转换为数组，只需让您的 TableModel 直接读取 TopicData 对象的 ArrayList，因此每个 TopicData 对应于一行。

主题表模型.java：

import java.util.ArrayList;

import javax.swing.table.AbstractTableModel;

public class TopicTableModel extends AbstractTableModel {

private static final long serialVersionUID = 1L;
private String[] columnNames = {"Name", "Date", "User"};
private ArrayList<TopicData> data;

public TopicTableModel(ArrayList<TopicData> listOfObjects) {
    data = listOfObjects;
} 

@Override
public int getColumnCount() {
    return columnNames.length;
}

@Override
public int getRowCount() {
    return data.size();
}

@Override
public String getColumnName(int col) {
    return columnNames[col];
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    switch (column) {
    case 0:
        return data.getName();
    case 1:
        return data.getDate();
    case 2:
        return data.getUser();
    default:
        throw new ArrayIndexOutOfBoundsException();
    }
}

@Override
public boolean isCellEditable(int rowIndex, int colIndex) {
    return false; //Disallow the editing of any cell
}

public TopicData getTopic(int row) {
    return data.get(row);
}

}

通过对 TopicView.java 进行一些小的修改，您现在可以获得所选行的 TopicData 并打印其 ID。

主题视图.java：

import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;


public class TopicView {
    JTable table;

    private JTable getTable() {
        if (table == null) {
            TopicData topic= new TopicData();
            final TopicTableModel tableModel = new TopicTableModel(topic.getTopicList());
            table = new JTable(tableModel);

            table.setShowGrid(false);
            table.setFillsViewportHeight(true);
            table.setBounds(173, 87, 456, 263);
            table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
            table.getTableHeader().setReorderingAllowed(false);
            table.getTableHeader().setResizingAllowed(false);
            table.getColumnModel().getColumn(0).setPreferredWidth(500);
            table.setDefaultRenderer(TopicData.class, new TopicDataTableCellRenderer());

            ListSelectionModel rowSM = table.getSelectionModel();
            rowSM.addListSelectionListener(new ListSelectionListener() {
                public void valueChanged(ListSelectionEvent e) {
                    //Ignore extra messages.
                    if (e.getValueIsAdjusting()) return;

                    int row = table.getSelectedRow();
                    if (row < 0) {
                        System.out.println("No rows are selected.");
                    }
                    else {
                        System.out.println("id " + tableModel.getTopic(row).getId() + " is now selected.");
                    }
                }
            });
        }
        return table;
    }
}
于 2013-01-11T18:47:59.990 回答
3

实际上，您的一切都在您的眼皮底下。

您需要做的就是更改您的TableModel，以便它保留ArrayList而不是将该列表转换为Object[][].

像这样的东西（可能有一些错字问题）：

public class TopicTableModel extends AbstractTableModel {

private static final long serialVersionUID = 1L;
private int rowCount, colCount;
private String[] columnNames = {"ID", "Name", "Date", "User"};
private List<TopicData> listOfObjects;
public TopicTableModel(ArrayList<TopicData> listOfObjects) {
    this.listOfObjects = listOfObjects;
} 

@Override
public int getColumnCount() {
    return columnNames.length;
}

@Override
public int getRowCount() {
    return listOfObjects.size();
}

@Override
public String getColumnName(int col) {
    return columnNames[col];
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    TopicData data = listOfObjects.get(rowIndex);
    switch(columnIndex) {
        case 0:
            return data.getId();
        case 1:
            return data.getName();
        case 2:
            return data.getDate();
        case 3:
            return data.getUser();
    }
    return null;
}

@Override
public boolean isCellEditable(int rowIndex, int colIndex) {
    return false; //Disallow the editing of any cell
}

}

副作用：TopicData Serializable如果您使用 Java 序列化（或其他利用Serializable.

于 2013-01-11T18:37:22.623 回答