如何在不使用IDE /外部工具的情况下在Java程序和数据库之间建立连接？

Question

I want to write a Java Program for Establishing Connection between Java Program and Database, but I don't want to use any IDE like Netbeans, Eclipse, Visual Studio, XAMP, etc. I have jar files for Driver of required DBMS.

 public class JDBCDemo { public static void main(String args[]) { try { /** * Steps for Establishing Connection between Java Application and Database */ //1. Load and Reginster Driver Class.forName("com.mysql.jdbc.Driver"); //2. Establish a connection between Java Application and Database Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/practicals", "root", "root123"); //3. Create Statement Object Statement st = con.createStatement(); //4. Send and Execute SQL queries ResultSet rs = st.executeQuery("SELECT * FROM tushar"); //5. Process the result from ResultSet object while(rs.next()) { System.out.println(rs.getString(1)); } //6. Close the Connection con.close(); } catch(Exception e) { System.out.println(e.toString().trim()); } } } 

It is showing error java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

How to Establish connection ??

Answer 1

You need to add the mysql driver jar in the classpath before you run the program.

There are various ways to do so.

1. javac -cp "JAR_PATH" ClassName.java java -cp "JAR_PATH" ClassName

2. Add the jar file in C:\\Program Files\\Java\\\\jre\\lib\\ext

3. set classpath=PATH_TO_JAR;

Answer 2

colon(:) is compulsory after jar file name

Compilling Program

javac -cp mysql-connector.jar: ProgramFileName.java

javac -cp mysql-connector.jar: JDBCDemo.java

Running Program

java -cp mysql-connector.jar: ProgramFileName

java -cp mysql-connector.jar: JDBCDemo

Note:- Simillar can be applied while using other jar files for performing other operations.

Sample Output