java.sql.SQLException：没有找到适合jdbc：microsoft：sqlserver的驱动程序

当我尝试运行此程序时，我遇到此异常。这是微软的例子之一。我已通过项目属性将 sqljdbc4.jar 添加到 netbeans 中的类路径中，用于编译和运行。我还测试了是否可以使用下面的 import 语句找到该类 - 编译期间没有错误，因此它必须找到 jar。

它是否与 sqldbc4.jar引用的 dll 或某些 sql dll 有关？

这是确切的例外，下面是确切的代码，密码除外。

例外：

run:
java.sql.SQLException: No suitable driver found for jdbc:microsoft:sqlserver://localhost:1433;databaseName=HealthCareDatabase
Error Trace in getConnection() : No suitable driver found for jdbc:microsoft:sqlserver://localhost:1433;databaseName=HealthCareDatabase
Error: No active Connection
    at java.sql.DriverManager.getConnection(DriverManager.java:602)
    at java.sql.DriverManager.getConnection(DriverManager.java:185)
    at javaapplication1.Connect.getConnection(Connect.java:35)
    at javaapplication1.Connect.displayDbProperties(Connect.java:50)
    at javaapplication1.JavaApplication1.main(JavaApplication1.java:23)
BUILD SUCCESSFUL (total time: 1 second)

法典：

 package javaapplication1;
import com.microsoft.sqlserver.jdbc.SQLServerDriver;

import java.*;

public class Connect {

    private java.sql.Connection con = null;
    private final String url = "jdbc:microsoft:sqlserver://";
    private final String serverName = "localhost";
    private final String portNumber = "1433";
    private final String databaseName = "HealthCareDatabase";
    private final String userName = "larry";
    private final String password = "xxxxxxx";

    // Constructor
    public Connect() {
    }

    private String getConnectionUrl() {
        return url + serverName + ":" + portNumber + ";databaseName=" + databaseName ;
    }

    private java.sql.Connection getConnection() {
        try {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
            con = java.sql.DriverManager.getConnection(getConnectionUrl(), userName, password);
            if (con != null) {
                System.out.println("Connection Successful!");
            }
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("Error Trace in getConnection() : " + e.getMessage());
        }
        return con;
    }

    public void displayDbProperties() {
        java.sql.DatabaseMetaData dm = null;
        java.sql.ResultSet rs = null;
        try {
            con = this.getConnection();
            if (con != null) {
                dm = con.getMetaData();
                System.out.println("Driver Information");
                System.out.println("\tDriver Name: " + dm.getDriverName());
                System.out.println("\tDriver Version: " + dm.getDriverVersion());
                System.out.println("\nDatabase Information ");
                System.out.println("\tDatabase Name: " + dm.getDatabaseProductName());
                System.out.println("\tDatabase Version: " + dm.getDatabaseProductVersion());
                System.out.println("Avalilable Catalogs ");
                rs = dm.getCatalogs();
                while (rs.next()) {
                    System.out.println("\tcatalog: " + rs.getString(1));
                }
                rs.close();
                rs = null;
                closeConnection();
            } else {
                System.out.println("Error: No active Connection");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        dm = null;
    }

    private void closeConnection() {
        try {
            if (con != null) {
                con.close();
            }
            con = null;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws Exception {
        Connect myDbTest = new Connect();
        myDbTest.displayDbProperties();
    }

}