Azure Java Web App将库添加到Classpath-Java 学习之路

我需要将sqljdbc42.jar库添加到classpath，以便我可以连接到Azure SQL数据库 . 如何（如果可能）我可以在Azure Web服务 - Web App（带有Tomcat服务器的Java）中执行此操作 . 有没有其他方法可以添加JDBC库？

服务器错误：

java.sql.SQLException: No suitable driver found for jdbc:sqlserver://XXXXXXX.database.windows.net:1433;database=XXXXXX;user=XXXXX@XXXXX;password=XXXXXXXX;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;
    at java.sql.DriverManager.getConnection(DriverManager.java:689)
    at java.sql.DriverManager.getConnection(DriverManager.java:270)
    at common.DBConnection.<init>(DBConnection.java:23)
    at servlets.Login.doPost(Login.java:77)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)
Dec 30, 2015 3:04:48 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [servlets.Login] in context with path [/deviceweb] threw exception
java.lang.NullPointerException
    at common.DBConnection.addParameter(DBConnection.java:33)
    at servlets.Login.doPost(Login.java:78)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

网页错误：

type: Exception report

    message:

    description: The server encountered an internal error that prevented it from fulfilling this request.

    exception:

    java.lang.NullPointerException
        common.DBConnection.addParameter(DBConnection.java:33)
        servlets.Login.doPost(Login.java:78)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note: The full stack trace of the root cause is available in the Apache Tomcat/8.0.30 logs.

连接字符串：

String connectionString = "jdbc:sqlserver://testnabaza.database.windows.net:1433;" + "database=testnabaza;"
            + "user=butterbeast@testnabaza;" + "password=1!qQaaaaaa;" + "encrypt=true;"
            + "trustServerCertificate=false;" + "hostNameInCertificate=*.database.windows.net;" + "loginTimeout=30;";

从Portal复制：jdbc：sqlserver：//testnabaza.database.windows.net：1433; database = testnabaza; user = butterbeast @ testnabaza; password = ; encrypt = true; trustServerCertificate = false; hostNameInCertificate = * .database . windows.net; loginTimeout = 30;

3 回答

0

最简单的方法是在创建之前，将sqljdbc42.jar文件（可能位于C：\ Program Files \ Microsoft SQL Server JDBC Driver \ sqljdbc_3.X \ enu中）添加到本地Java安装的\ lib \ ext目录中 . .zip文件 .

为了获得最佳帮助，请使用给定的链接https://dzone.com/articles/java-access-sql-azure-jdbc

回复于 2024-04-25T05:30:25+08:00
2
根据我的经验，将 sqljdbc42.jar 库（请从官方网站https://www.microsoft.com/en-US/download/details.aspx?id=11774下载）添加到类路径的简单方法是将jdbc驱动程序文件拖放或复制到Eclipse中 Dynamic Web Project 的 WebContent/WEB-INF/lib 目录中，请参见下图 .

从Eclipse中的项目导出war文件时，库文件将包含在其中 . 然后，您可以使用Tomcat将war文件部署到Azure WebApp for Java中，它将正常工作 .

大多数情况下的异常 java.sql.SQLException: No suitable driver found 是由不正确的URL引起的 . 请检查您的连接字符串并正确使用它进行Java jdbc编程 .

作为参考，这是我的简单代码 .
```
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
String jdbcUrl = "jdbc:sqlserver://<host>.database.windows.net:1433;database=<database>;user=<username>@<host>;password=<password>;encrypt=true;hostNameInCertificate=*.database.windows.net;loginTimeout=30;";
String user = "<username>@<host>";
String password = "<password>";
Connection conn = DriverManager.getConnection(jdbcUrl, user, password);
PreparedStatement statement = conn.prepareStatement("select 1 as id, 'peter' as name");
ResultSet rs = statement.executeQuery();
while(rs.next()) {
    System.out.println(rs.getLong("id")+","+rs.getString("name"));
}
rs.close();
statement.close();
```
回复于 2024-04-25T05:30:25+08:00
2

我收到了Azure团队的回复，他说我不太可能通过Web App解决这个问题，但我需要创建Cloud Service：

不幸的是，JDBC库属于Tomcat几乎强迫您将它们放入CATALINA_HOME \ lib的区域，但是您需要确保您放入的驱动程序适用于该Tomcat中的所有Web应用程序 . 从我记忆中，这与Tomcat内存泄漏预防有关，这使得Tomcat仅在Tomcat启动时扫描CATALINA_HOME \ lib一次用于数据库驱动程序 . 这样做有很好的理由与驱动程序如何在JVM中注册以及它如何影响类加载器有关 . 即使您想要禁用此行为，您也必须编辑server.xml，这将再次驱动您拥有自己的Tomcat安装 . 因此，我漫无边际叙述的结果是您需要从库中安装Tomcat或上传您自己的版本，然后将您的JDBC驱动程序放在Tomcat \ lib目录中 . 您正试图通过为您的应用程序启用Java的UI来做更多的事情 .

https://azure.microsoft.com/en-us/documentation/articles/web-sites-java-add-app/

互联网上有过时的教程，但可以帮助找出要做的事情 . subhash singh 链接帮助了我一般的想法，但教程已经过时，有点令人困惑 .

回复于 2024-04-25T05:30:25+08:00

Azure Java Web App将库添加到Classpath

3 回答

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