在 Java 中使用 JTable 显示 MySQL 数据库中的记录

Display Records From MySQL Database using JTable in Java

提问by user3331023

I want to connect a JTableto a ResultSetfrom a MySQL database so I can view the data.

我想将 a从 MySQL 数据库连接JTable到 a ResultSet，以便我可以查看数据。

I am looking for some links or code snippets describing this task. I'm using the Netbeans IDE..

我正在寻找一些描述此任务的链接或代码片段。我正在使用 Netbeans IDE ..

回答by Derek W

Below is a class which will accomplish the very basics of what you want to do when reading data from a MySQL database into a JTablein Java.

下面是一个类，它将完成您在将数据从 MySQL 数据库读取到JTableJava 中时想要执行的操作的基础知识。

import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;

public class TableFromMySqlDatabase extends JFrame
{
    public TableFromMySqlDatabase()
    {
        ArrayList columnNames = new ArrayList();
        ArrayList data = new ArrayList();

        //  Connect to an MySQL Database, run query, get result set
        String url = "jdbc:mysql://localhost:3306/yourdb";
        String userid = "root";
        String password = "sesame";
        String sql = "SELECT * FROM animals";

        // Java SE 7 has try-with-resources
        // This will ensure that the sql objects are closed when the program 
        // is finished with them
        try (Connection connection = DriverManager.getConnection( url, userid, password );
            Statement stmt = connection.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.add( md.getColumnName(i) );
            }

            //  Get row data
            while (rs.next())
            {
                ArrayList row = new ArrayList(columns);

                for (int i = 1; i <= columns; i++)
                {
                    row.add( rs.getObject(i) );
                }

                data.add( row );
            }
        }
        catch (SQLException e)
        {
            System.out.println( e.getMessage() );
        }

        // Create Vectors and copy over elements from ArrayLists to them
        // Vector is deprecated but I am using them in this example to keep 
        // things simple - the best practice would be to create a custom defined
        // class which inherits from the AbstractTableModel class
        Vector columnNamesVector = new Vector();
        Vector dataVector = new Vector();

        for (int i = 0; i < data.size(); i++)
        {
            ArrayList subArray = (ArrayList)data.get(i);
            Vector subVector = new Vector();
            for (int j = 0; j < subArray.size(); j++)
            {
                subVector.add(subArray.get(j));
            }
            dataVector.add(subVector);
        }

        for (int i = 0; i < columnNames.size(); i++ )
            columnNamesVector.add(columnNames.get(i));

        //  Create table with database data    
        JTable table = new JTable(dataVector, columnNamesVector)
        {
            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 );
        getContentPane().add( scrollPane );

        JPanel buttonPanel = new JPanel();
        getContentPane().add( buttonPanel, BorderLayout.SOUTH );
    }

    public static void main(String[] args)
    {
        TableFromMySqlDatabase frame = new TableFromMySqlDatabase();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible(true);
    }
}

In the NetBeans IDE which you are using - you will need to add the MySQL JDBC Driverin Project Properties as I display here:

在您使用的 NetBeans IDE 中 - 您需要在项目属性中添加MySQL JDBC 驱动程序，如下所示：

Otherwise the code will throw an SQLExceptionstating that the driver cannot be found.

否则，代码将抛出SQLException无法找到驱动程序的声明。

Now in my example, yourdbis the name of the database and animalsis the name of the table that I am performing a query against.

现在在我的示例中，yourdb是数据库animals的名称，是我正在执行查询的表的名称。

Here is what will be output:

这是将输出的内容：

Parting note:

离别说明：

You stated that you were a novice and needed some help understanding some of the basic classes and concepts of Java. I will list a few here, but remember you can always browse the docs on Oracle's site.

你说你是一个新手，需要一些帮助来理解 Java 的一些基本类和概念。我将在这里列出一些，但请记住，您可以随时浏览 Oracle 站点上的文档。

• ArrayList
• Vector
• Try-with-resources statement

• 数组列表
• 向量
• Try-with-resources 语句

回答by Sparrow7000

If you need to work a lot with database in your code and you know the structure of your table, I suggest you do it as follow:

如果您需要在代码中大量使用数据库并且您知道表的结构，我建议您按如下方式操作：

First of all you can define a class which will help you to make objects capable of keeping your table rows data. For example in my project I created a class named Document.javato keep data of a single document from my database and I made an array list of these objects to keep data of my table which is gain by a query.

首先，您可以定义一个类，它可以帮助您创建能够保存表格行数据的对象。例如，在我的项目中，我创建了一个名为Document.java的类来保存我的数据库中单个文档的数据，并且我制作了这些对象的数组列表来保存我的表的数据，这些数据是通过查询获得的。

package financialdocuments;

import java.lang.*;
import java.util.HashMap;

/**
 *
 * @author Administrator
 */
public class Document {

 private int document_number; 
 private boolean document_type;
 private boolean document_status; 
 private StringBuilder document_date;
 private StringBuilder document_statement;
 private int document_code_number;
 private int document_employee_number;
 private int document_client_number;
 private String document_employee_name;
 private String document_client_name;
 private long document_amount;
 private long document_payment_amount;

 HashMap<Integer,Activity> document_activity_hashmap;


public Document(int dn,boolean dt,boolean ds,String dd,String dst,int dcon,int den,int dcln,long da,String dena,String dcna){

    document_date = new StringBuilder(dd);
    document_date.setLength(10);
    document_date.setCharAt(4, '.');
    document_date.setCharAt(7, '.');
    document_statement = new StringBuilder(dst);
    document_statement.setLength(50);
    document_number = dn; 
    document_type = dt;
    document_status = ds;
    document_code_number = dcon;
    document_employee_number = den;
    document_client_number = dcln;
    document_amount = da;
    document_employee_name = dena;
    document_client_name = dcna;

    document_payment_amount = 0;

    document_activity_hashmap = new HashMap<>();

}

public Document(int dn,boolean dt,boolean ds, long dpa){

    document_number = dn; 
    document_type = dt;
    document_status = ds;

    document_payment_amount = dpa;

    document_activity_hashmap = new HashMap<>();

}

// Print document information 
public void printDocumentInformation (){
    System.out.println("Document Number:" + document_number); 
    System.out.println("Document Date:" + document_date); 
    System.out.println("Document Type:" + document_type); 
    System.out.println("Document Status:" + document_status); 
    System.out.println("Document Statement:" + document_statement); 
    System.out.println("Document Code Number:" + document_code_number); 
    System.out.println("Document Client Number:" + document_client_number); 
    System.out.println("Document Employee Number:" + document_employee_number); 
    System.out.println("Document Amount:" + document_amount); 
    System.out.println("Document Payment Amount:" + document_payment_amount); 
    System.out.println("Document Employee Name:" + document_employee_name); 
    System.out.println("Document Client Name:" + document_client_name); 

} 
} 

Second of all, you can define a class to handle your database needs. For example I defined a class named DataBase.javawhich handles my connections to the database and my needed queries. And I instantiated an objected of it in my main class.

其次，您可以定义一个类来处理您的数据库需求。例如，我定义了一个名为DataBase.java的类，它处理我与数据库的连接和我需要的查询。我在我的主类中实例化了一个对象。

package financialdocuments;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Administrator
 */
public class DataBase {

/** 
 * 
 * Defining parameters and strings that are going to be used
 * 
 */
//Connection connect;

// Tables which their datas are extracted at the beginning 
HashMap<Integer,String> code_table;
HashMap<Integer,String> activity_table;
HashMap<Integer,String> client_table;
HashMap<Integer,String> employee_table;

// Resultset Returned by queries 
private ResultSet result;

// Strings needed to set connection
String url = "jdbc:mysql://localhost:3306/financial_documents?useUnicode=yes&characterEncoding=UTF-8";
String dbName = "financial_documents";
String driver = "com.mysql.jdbc.Driver";
String userName = "root"; 
String password = "";

public DataBase(){

    code_table = new HashMap<>();
    activity_table = new HashMap<>();
    client_table = new HashMap<>();
    employee_table = new HashMap<>();
    Initialize();

}

/**
 * Set variables and objects for this class.
 */
private void Initialize(){

    System.out.println("Loading driver..."); 
    try {
        Class.forName(driver);
        System.out.println("Driver loaded!"); 
    } catch (ClassNotFoundException e) { 
        throw new IllegalStateException("Cannot find the driver in the classpath!", e); 
    }

    System.out.println("Connecting database...");

try (Connection connect = DriverManager.getConnection(url,userName,password)) {
            System.out.println("Database connected!");
            //Get tables' information 
            selectCodeTableQueryArray(connect);
           // System.out.println("HshMap Print:");
           // printCodeTableQueryArray();

            selectActivityTableQueryArray(connect);
           // System.out.println("HshMap Print:");
           // printActivityTableQueryArray(); 

            selectClientTableQueryArray(connect);
           // System.out.println("HshMap Print:");
           // printClientTableQueryArray();

            selectEmployeeTableQueryArray(connect);
           // System.out.println("HshMap Print:");
           // printEmployeeTableQueryArray();

            connect.close();
    }catch (SQLException e) { 
        throw new IllegalStateException("Cannot connect the database!", e);
    }

} 

/**
 * Write Queries 
 * @param s
 * @return 
 */
public boolean insertQuery(String s){

    boolean ret = false;
    System.out.println("Loading driver..."); 
    try {
        Class.forName(driver);
        System.out.println("Driver loaded!"); 
    } catch (ClassNotFoundException e) { 
        throw new IllegalStateException("Cannot find the driver in the classpath!", e); 
    }

    System.out.println("Connecting database...");

try (Connection connect = DriverManager.getConnection(url,userName,password)) {
            System.out.println("Database connected!");
            //Set tables' information 
            try {
                Statement st = connect.createStatement();
                int val = st.executeUpdate(s);
                if(val==1){ 
                    System.out.print("Successfully inserted value");
                    ret = true;
                }
                else{ 
                    System.out.print("Unsuccessful insertion");
                    ret = false;
                }
                st.close();
            } catch (SQLException ex) {
                Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
            }
            connect.close();
    }catch (SQLException e) { 
        throw new IllegalStateException("Cannot connect the database!", e);
    } 
    return ret;
}

/**
 * Query needed to get code table's data
 * @param c
 * @return 
 */
private void selectCodeTableQueryArray(Connection c) {
    try {
        Statement st = c.createStatement();
        ResultSet res = st.executeQuery("SELECT * FROM  code;");
        while (res.next()) {
                int id = res.getInt("code_number");
                String msg = res.getString("code_statement");
                code_table.put(id, msg);
            }
        st.close();
    } catch (SQLException ex) {
        Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private void printCodeTableQueryArray() {
    for (HashMap.Entry<Integer ,String> entry : code_table.entrySet()){
        System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
    }
}

/**
 * Query needed to get activity table's data
 * @param c
 * @return 
 */
private void selectActivityTableQueryArray(Connection c) {
    try {
        Statement st = c.createStatement();
        ResultSet res = st.executeQuery("SELECT * FROM  activity;");
        while (res.next()) {
                int id = res.getInt("activity_number");
                String msg = res.getString("activity_statement");
                activity_table.put(id, msg);
            }
        st.close();
    } catch (SQLException ex) {
        Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private void printActivityTableQueryArray() {
    for (HashMap.Entry<Integer ,String> entry : activity_table.entrySet()){
        System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
    }
}

/**
 * Query needed to get client table's data
 * @param c
 * @return 
 */
private void selectClientTableQueryArray(Connection c) {
    try {
        Statement st = c.createStatement();
        ResultSet res = st.executeQuery("SELECT * FROM  client;");
        while (res.next()) {
                int id = res.getInt("client_number");
                String msg = res.getString("client_full_name");
                client_table.put(id, msg);
            }
        st.close();
    } catch (SQLException ex) {
        Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private void printClientTableQueryArray() {
    for (HashMap.Entry<Integer ,String> entry : client_table.entrySet()){
        System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
    }
}

/**
 * Query needed to get activity table's data
 * @param c
 * @return 
 */
private void selectEmployeeTableQueryArray(Connection c) {
    try {
        Statement st = c.createStatement();
        ResultSet res = st.executeQuery("SELECT * FROM  employee;");
        while (res.next()) {
                int id = res.getInt("employee_number");
                String msg = res.getString("employee_full_name");
                employee_table.put(id, msg);
            }
        st.close();
    } catch (SQLException ex) {
        Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private void printEmployeeTableQueryArray() {
    for (HashMap.Entry<Integer ,String> entry : employee_table.entrySet()){
        System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
    }
} 
}

I hope this could be a little help.

我希望这会有点帮助。

回答by Walid Bousseta

this is the easy way to do that you just need to download the jar file "rs2xml.jar"add it to your project and do that : 1- creat a connection 2- statment and resultset 3- creat a jtable 4- give the result set to DbUtils.resultSetToTableModel(rs)as define in this methode you well get your jtable so easy.

这是一种简单的方法，您只需要下载 jar 文件"rs2xml.jar"并将其添加到您的项目中并执行此操作：1- 创建连接 2- 语句和结果集 3- 创建一个 jtable 4- 将结果集DbUtils.resultSetToTableModel(rs)定义为这个方法你很容易得到你的jtable。

public void afficherAll(String tableName){
        String sql="select * from "+tableName;
        try {
            stmt=con.createStatement();
            rs=stmt.executeQuery(sql);
            tbContTable.setModel(DbUtils.resultSetToTableModel(rs));
        } catch (SQLException e) {
            // TODO Auto-generated catch block
             JOptionPane.showMessageDialog(null, e);
        }       
    }