java.lang.ClassNotFoundException Netbeans java derby

问题描述

我使用Netbeans，做一个java应用程序。我在netbeans中使用Java DB创建了一个类ConnectDB for db connetion。我启动了服务器和十个连接到db。当我运行它生成的文件

  java.lang.ClassNotFoundException：org.apache.derby.jdbc.ClientDriver @ 25 line 
  

和

  java.sql.SQLException：没有找到适合的驱动程序jdbc：derby：// localhost：1527 / Libraryprj; create = true 
  

@第30行代码

代码如下

  package Lms; 
 
 import java.sql.Connection; 
 import java.sql.DriverManager; 
 import java.sql.PreparedStatement; 
 import java.sql.ResultSet; 
 import java.sql.Statement; 
 
 / ** 
 * 
 * @author JOJO 
 * / 
 public class ConnectDB {
 static Connection conn; 
 
 public static void main（String [] args）{
 String driver =org.apache.derby.jdbc.ClientDriver; 
 String connectionURL =jdbc：derby：// localhost：1527 / Libraryprj; create = true; 
 String createString =CREATE TABLE Employee（NAME VARCHAR（32）NOT NULL，ADDRESS VARCHAR（50）NOT NULL）; 
 try {
 Class.forName（driver）; 
} catch（java.lang.ClassNotFoundException e）{
 e.printStackTrace（）; 
} 
 try {
 conn = DriverManager.getConnection（connectionURL）; 
语句stmt =（Statement）conn.createStatement（）; 
 stmt.executeUpdate（createString）; 
 
 PreparedStatement psInsert = conn.prepareStatement（insert into Employee values（？，？））; 
 
 psInsert.setString（1，args [0]）; $ b $ p psInsert.setString（2，args [1]）; 
 
 psInsert.executeUpdate（）; 
 
语句stmt2 =（Statement）conn.createStatement（）; 
 ResultSet rs = stmt2.executeQuery（select * from Employee）; 
 int num = 0; 
 while（rs.next（））{
 System.out.println（++ num +：Name：+ rs.getString（1）+\\\
 Address+ rs.getString （2））; 
} 
 rs.close（）; 
} catch（Exception e）{
 e.printStackTrace（）; 
} 
} 
} 
  

解决方案>

如果您使用Tomcat，请从下载derbyclient.jar。并将jar文件复制到Tomcat的lib文件夹。

I use Netbeans, doing a java app. I created a class ConnectDB for db connetion using Java DB in netbeans. i started the server and ten conneted to db. when i run the file it produce

java.lang.ClassNotFoundException: org.apache.derby.jdbc.ClientDriver @ 25 line

and

java.sql.SQLException: No suitable driver found for jdbc:derby://localhost:1527/Libraryprj;create=true

@30 th line of code

the code is below

package Lms;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 *
 * @author JOJO
 */
public class ConnectDB {
  static Connection conn;

  public static void main(String[] args) {
    String driver = "org.apache.derby.jdbc.ClientDriver";
    String connectionURL = "jdbc:derby://localhost:1527/Libraryprj;create=true";
    String createString = "CREATE TABLE Employee (NAME VARCHAR(32) NOT NULL, ADDRESS VARCHAR(50) NOT NULL)";
    try {
      Class.forName(driver);
    } catch (java.lang.ClassNotFoundException e) {
      e.printStackTrace();
    }
    try {
      conn = DriverManager.getConnection(connectionURL);
      Statement stmt = (Statement) conn.createStatement();
      stmt.executeUpdate(createString);

      PreparedStatement psInsert = conn.prepareStatement("insert into Employee values (?,?)");

      psInsert.setString(1, args[0]);
      psInsert.setString(2, args[1]);

      psInsert.executeUpdate();

      Statement stmt2 = (Statement) conn.createStatement();
      ResultSet rs = stmt2.executeQuery("select * from Employee");
      int num = 0;
      while (rs.next()) {
        System.out.println(++num + ": Name: " + rs.getString(1) + "\n Address" + rs.getString(2));
      }
      rs.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

解决方案

If you use Tomcat download derbyclient.jar from here . And copy the jar file to Tomcat's lib folder.

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