Java 做GUI出现如下报错，求大佬帮助
0
[已解决问题]
解决于 2023-02-09 15:43
在做GUI程序的时候在连接数据库的时候出现了这样的报错，经过一番查询仍然未能正确修改，希望有懂的大佬帮助一下小白。
jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=StudentManager
com.microsoft.jdbc.sqlserver.SQLServerDriver
Can't Find Database Driver.
SqlManager:Connecting to database...
connectDBNo suitable driver found for jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=StudentManager
SqlManager:Connect to database successful.
Exception in thread "main" java.lang.NullPointerException: Cannot invoke "java.sql.Statement.executeQuery(String)" because "this.Sqlstmt" is null
at SqlManager.executeQuery(SqlManager.java:111)
at AdmPanel.createStuPanel(AdmPanel.java:133)
at AdmPanel.<init>(AdmPanel.java:114)
at MyFrame.<init>(MyFrame.java:20)
at StudentMain.main(StudentMain.java:5)
问题补充：
在网上搜的时候找到了这样一个讨论（地址：https://stackoverflow.com/questions/68376293/java-lang-nullpointerexception-cannot-invoke-java-sql-statement-executequerys）
在网上搜的时候找到了这样一个讨论（地址：https://stackoverflow.com/questions/68376293/java-lang-nullpointerexception-cannot-invoke-java-sql-statement-executequerys）
然后我就加了这么条语句
接下来报错就成了这：Exception in thread "main" java.lang.NoClassDefFoundError: Logon
at StudentMain.main(StudentMain.java:5)
Caused by: java.lang.ClassNotFoundException: Logon
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:606)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:168)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 1 more
求大佬帮忙
最佳答案
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try (Connection connection = DriverManager.getConnection(connStr);
Statement statement = connection.createStatement()) {
var resultSet= statement.executeQuery("select top 100 column1 from table1");
while (resultSet.next()){
System.out.println((resultSet.getString(1)));
}
} catch (SQLException e) {
e.printStackTrace();
}
奖励园豆：5
好的 好的 非常感谢您的回复
