java.sql.SQLException：找不到适用于jdbc：microsoft：

Question

当我尝试运行此程序时，出现此异常。这是微软的例子之一。我已经通过项目属性将sqljdbc4.jar添加到了netbeans的类路径中，以便进行编译和运行。我还测试了可以使用下面的import语句找到该类-编译期间没有错误，因此它必须找到jar。可能与sqldbc4.jar引用的dll或某些sql dll相关吗？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=HealthCareDatabaseError Trace in getConnection() : No suitable driver found for jdbc:microsoft:sqlserver://localhost:1433;databaseName=HealthCareDatabaseError: 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)码： 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 ;    }