Debugging Database connection

From Java Example Source Code

Jump to: navigation, search

Contents

[edit] Overview - Debugging Database connection

This Java example program demonstrates how to debug database connection.

[edit] Java Source Code

  • Package: example.sql.connection
  • File: TestDebug_MySQL.java
package example.sql.connection;
 
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
public class TestDebug_MySQL {
    public static Connection getConnection() throws Exception {
	String driver = "org.gjt.mm.mysql.Driver";
	String url = "jdbc:mysql://localhost/octopus";
	String username = "root";
	String password = "root";
	Class.forName(driver);
	return DriverManager.getConnection(url, username, password);
    }
 
    public static int countRows(Connection conn, String tableName) throws SQLException {
	Statement stmt = null;
	ResultSet rs = null;
	int rowCount = -1;
	try {
	    stmt = conn.createStatement();
	    rs = stmt.executeQuery("SELECT COUNT(*) FROM " + tableName);
	    // get the number of rows from the result set
	    rs.next();
	    rowCount = rs.getInt(1);
	} finally {
	    rs.close();
	    stmt.close();
	}
 
	return rowCount;
    }
 
    public static void main(String[] args) {
	Connection conn = null;
	try {
	    PrintWriter pw = new PrintWriter(new FileOutputStream("mysql_debug.txt"));
	    DriverManager.setLogWriter(pw);
	    conn = getConnection();
	    String tableName = "myTable";
	    System.out.println("tableName=" + tableName);
	    System.out.println("conn=" + conn);
	    System.out.println("rowCount=" + countRows(conn, tableName));
	} catch (Exception e) {
	    e.printStackTrace();
	    System.exit(1);
	} finally {
	    try {
		conn.close();
	    } catch (SQLException e) {
		e.printStackTrace();
	    }
	}
    }
}

[edit] What Result You Can Get

Coming soon... Run the program, you will get:

[edit] Required External Libraries and/or Files for this Java Example

In order to run this Java example, one of the following libraries may be required:


[edit] How to Run this Java Example Program

We recommend running this Java example program with Eclipse.

For assistance in working with Eclipse, please see How to Run Java Program with Eclipse.

It's fairly easy.



[edit] Question & Answer

Any question?

Click edit and post your question or answer here.


Personal tools