在代码上获取ClassNotFoundException：" Class.forName（" com.microsoft.sqlserver.jdbc.SqlServerDriver"）;" [英] Getting ClassNotFoundException on code: "Class.forName("com.microsoft.sqlserver.jdbc.SqlServerDriver");"

问题描述

这是我的第一个 Java 应用程序，我对 Java 和 NetBeans 完全缺乏经验。

This is my first Java application and I'm completely inexperienced with Java and NetBeans.

我一直在尝试连接到sql并获取一些记录2天。问题是关于 jdbc 驱动程序，让我解释一下。我已经下载了 sqljdbc 驱动程序，然后按照以下步骤操作：

I have been trying to connect to sql and get some records for 2 days. The problem is about jdbc driver, let me explain. I have downloaded sqljdbc driver and then followed these steps:

右键单击Project->选择属性 - >在左侧单击Libraries-> Compile选项卡 - 单击Add Jar / Folder按钮并选择 sqljdbc4.jar 文件。然后它应该没问题，对吧？

Right-click Project->Select Properties->On the left-hand side click Libraries->Under Compile tab - click Add Jar/Folder button and select sqljdbc4.jar file. Then it should be ok, right?

然后我写了这段代码但是我不能摆脱这个例外：

Then I wrote this code But I cant get rid of this exception:

  Exception in thread "main" java.lang.ClassNotFoundException: 
  com.microsoft.sqlserver.jdbc.SqlServerDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at javaapplication1.JavaApplication1.main(JavaApplication1.java:30)

这是代码

public static void main(String[] args) throws ClassNotFoundException, SQLException {
    String url = "jdbc:sqlserver://.\\SQLEXPRESS;databaseName=Northwind; Integrated Security = SSPI ";

    Connection con = null;
    Statement stmt = null;

    ResultSet rs = null;
    try {
        Class.forName("com.microsoft.sqlserver.jdbc.SqlServerDriver");

        con = DriverManager.getConnection(url);
        String sql = "Select Top 3 from * person.Contact";
        stmt = con.createStatement();
        rs = stmt.executeQuery(sql);
        while (rs.next()) {
            System.out.println(rs.getString(1));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

推荐答案

根据这个页面，该类名为 SQLServerDriver 而不是 SqlServerDriver 。案例很重要！

According to this page, the class is called SQLServerDriver and not SqlServerDriver. Case is important!

所以，试试：

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

请注意，对于较新版本的JDBC，没有必要明确加载驱动程序类使用 Class.forName（...）。我链接的页面明确说明您不必这样做。所以，你可以删除整行，然后它应该工作。

Note that with newer versions of JDBC, it's not necessary to load the driver class explicitly with Class.forName(...). The page I linked to explicitly explains that you don't have to do it. So, you can just remove the whole line and then it should work.

这篇关于在代码上获取ClassNotFoundException：" Class.forName（" com.microsoft.sqlserver.jdbc.SqlServerDriver"）;"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！