Java JDBC Intellij和SQLServer Experss

Question

由于某些原因，我的sql server数据库无法连接到我的intellij java应用程序。这是我第一次这么做，所以我不明白我做错了什么。

我用来连接数据库的代码是。

导入java.sql.*；

public class StudentDatabase{

static Connection con ;
static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver"; //com.microsoft.sqlserver.jdbc.SQLServerDriver
static String url = "jdbc:sqlserver://frensis\\sqlexpress;databaseName=StudentDatabase";
static String username = "Frensis\\Grid_Computers";
static String userpass = "";

public static Connection getConnection() {
    try {
        if (con == null) {
            Class.forName(driver);
            con = DriverManager.getConnection(url, username, userpass);

        }
    } catch (ClassNotFoundException ex)
    {
        ex.printStackTrace();
    }
    catch (SQLException ex)
    {
        ex.printStackTrace();
        System.out.println("Error Connecting to Database");
    }
    return con;
}

}

我得到的错误是。

“C:\Program Files\Java\jdk-17.0.2\bin\Java.exe”-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2.3\lib\IDEA_rt.jar=55405:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2.3\bin”-Dfile。encoding=UTF-8-类路径C:\Users\Grid\u Computers\IdeaProjects\BilancStudentApp\out\production\BilancStudentApp；C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\chs\mssql-jdbc-10.2.0。jre8。罐子C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\chs\mssql-jdbc-10.2.0。jre11。罐子C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\chs\mssql-jdbc-10.2.0。jre17。jar StudentAppcom。微软sqlserver。jdbc。SQLServerException:与主机frensis端口1433的TCP/IP连接失败。错误：“连接超时。请验证连接属性。确保SQL Server实例正在主机上运行，并在端口接受TCP/IP连接。确保到端口的TCP连接未被防火墙阻止。” 在com上。微软sqlserver。jdbc。SQLServerException。makeFromDriverError（SQLServerException.java:237）在com上。微软sqlserver。jdbc。SQLServerException。ConvertConnectExceptionToSQLServerException（SQLServerException.java:288）在com上。微软sqlserver。jdbc。SocketFinder。findSocket（IOBuffer.java:2720）在com上。微软sqlserver。jdbc。谢内尔。在com上打开（IOBuffer.java:761）。微软sqlserver。jdbc。SQLServerConnection。connectHelper（SQLServerConnection.java:3180）在com上。微软sqlserver。jdbc。SQLServerConnection。登录（SQLServerConnection.java:2833）com。微软sqlserver。jdbc。SQLServerConnection。ConnectionInternal（SQLServerConnection.java:2671）在com上。微软sqlserver。jdbc。SQLServerConnection。连接（SQLServerConnection.java:1640）在com上。微软sqlserver。jdbc。SQLServerDriver。在java上连接（SQLServerDriver.java:936）。sql/java。sql。司机经理。getConnection（DriverManager.java:681）位于java。sql/java。sql。司机经理。getConnection（DriverManager.java:229）位于StudentDatabase。getConnection（StudentDatabase.java:15）位于StudentApp。main（StudentApp.java:7）连接到数据库时出错

用退出代码0完成的进程

你能指导我如何解决这个问题，或者如何更改我的代码，以便我能够成功连接它吗？

经过几次更改后，我发现了一个与SSL相关的新错误：

"C:\Program Files\Java\jdk-17.0.2\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2.3\lib\idea_rt.jar=52938:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2.3\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\Grid_Computers\IdeaProjects\BilancStudentApp\out\production\BilancStudentApp;C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\enu\mssql-jdbc-10.2.0.jre8.jar;C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\enu\mssql-jdbc-10.2.0.jre11.jar;C:\Users\Grid_Computers\OneDrive\Desktop\sqljdbc_10.2\enu\mssql-jdbc-10.2.0.jre17.jar StudentApp
com.microsoft.sqlserver.jdbc.SQLServerException: The driver could not establish a secure connection to SQL Server by using Secure Sockets Layer (SSL) encryption. Error: "PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target". ClientConnectionId:58113aa8-cf71-4e9c-8d63-8820be9c1ab8
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.terminate(SQLServerConnection.java:3680)
    at com.microsoft.sqlserver.jdbc.TDSChannel.enableSSL(IOBuffer.java:2113)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:3204)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:2833)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:2671)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:1640)
    at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:936)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:681)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:229)
    at StudentDatabase.getConnection(StudentDatabase.java:15)
    at StudentApp.main(StudentApp.java:7)
Caused by: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:371)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:314)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:309)
    at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:654)
    at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(CertificateMessage.java:473)
    at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(CertificateMessage.java:369)
    at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:396)
    at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:480)
    at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:458)
    at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:201)
    at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:172)
    at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1500)
    at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1415)
    at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:450)
    at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:421)
    at com.microsoft.sqlserver.jdbc.TDSChannel.enableSSL(IOBuffer.java:2021)
    ... 9 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:439)
    at java.base/sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:306)
    at java.base/sun.security.validator.Validator.validate(Validator.java:264)
    at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:242)
    at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:113)
    at com.microsoft.sqlserver.jdbc.TDSChannel$HostNameOverrideX509TrustManager.checkServerTrusted(IOBuffer.java:1702)
    at java.base/sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(SSLContextImpl.java:1441)
    at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:638)
    ... 21 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
    at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
    at java.base/java.security.cert.CertPathBuilder.build(CertPathBuilder.java:297)
    at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:434)
    ... 28 more
Error Connecting to Database

Process finished with exit code 0




Answer 1

仔细检查JDBC url，如果没有问题，请确保MS SQL Server允许Configuration Manager中的JDBC连接，尤其是：

• 启用TCP/IP协议

您可以通过步骤和屏幕截图查看本指南。