java - Why I'm I getting Socket Factory not found?

Question

Error

MESSAGE:    java.lang.NoClassDefFoundError: com/google/cloud/sql/core/CoreSocketFactory
SERVLET:    HomePageServlet
CAUSED BY:  java.lang.NoClassDefFoundError: com/google/cloud/sql/core/CoreSocketFactory
Caused by:
java.lang.NoClassDefFoundError: com/google/cloud/sql/core/CoreSocketFactory
    at com.google.cloud.sql.mysql.SocketFactory.connect(SocketFactory.java:36)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284)
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:2565)
    at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at db.FilmDAO.openConnection(FilmDAO.java:55)
    at db.FilmDAO.getAllFilms(FilmDAO.java:90)
    at controllers.HomePageServlet.doGet(HomePageServlet.java:56)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.eclipse.jetty.servlet.ServletHolder$NotAsync.service(ServletHolder.java:1452)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:791)
    at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1626)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:134)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:48)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.appengine.tools.development.jetty9.StaticFileFilter.doFilter(StaticFileFilter.java:123)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at com.google.appengine.tools.development.DevAppServerRequestLogFilter.doFilter(DevAppServerRequestLogFilter.java:28)
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:201)
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:548)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:578)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1612)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1434)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1582)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1349)
    at com.google.appengine.tools.development.jetty9.DevAppEngineWebAppContext.doScope(DevAppEngineWebAppContext.java:94)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at com.google.appengine.tools.development.jetty9.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:610)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
    at org.eclipse.jetty.server.Server.handle(Server.java:516)
    at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383)
    at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
    at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:773)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:905)
    at java.lang.Thread.run(Thread.java:748)

Being caused by this line:

String url = "jdbc:mysql://google/films?cloudSqlInstance=emerald-mission-296018:europe-west1:film-db&socketFactory=com.google.cloud.sql.mysql.SocketFactory&useSSL=false&user=" + user;

Ive added socket factory and mysql to build patch of this GOogle App engine project

    <project>
    
    <!-- https://mvnrepository.com/artifact/javax.xml.bind/jaxb-api -->
    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.1</version>
    </dependency>

    
    <!-- https://mvnrepository.com/artifact/javax.activation/activation -->
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1</version>
    </dependency>
    
    <!-- https://mvnrepository.com/artifact/org.glassfish.jaxb/jaxb-runtime -->
    <dependency>
        <groupId>org.glassfish.jaxb</groupId>
        <artifactId>jaxb-runtime</artifactId>
        <version>2.3.0-b170127.1453</version>
    </dependency>

    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>2.3.0.1</version>
    </dependency>
    
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-core</artifactId>
        <version>2.3.0.1</version>
    </dependency>
    
    <dependency>
      <groupId>com.google.cloud.sql</groupId>
      <artifactId>mysql-socket-factory</artifactId>
      <version>1.0.15</version>
    </dependency>

</project>

Here is my pom.xml

Answer 1

The problem is that your project doesn't have the mysql-socket-factory dependency. Try to add this

<dependency>
    <groupId>com.google.cloud.sql</groupId>
    <artifactId>mysql-socket-factory</artifactId>
    <version>1.0.15</version>
</dependency>