如何使用JSF和PrimeFaces将上传的文件作为Blob存储在mysql数据库中

我想上传一个文件并保存到mysql数据库。到目前为止，我能够上传文件，打印其细节。但是，当我试图通过助手类将其存储在数据库中时，除ID之外的所有内容都将变为null。你能看一下让我知道我错过了什么吗？另外，如果您看到任何我应该更改/修改的代码增强，请告诉我

使用JSF/Primefaces上载文件：

    <h:form enctype="multipart/form-data">
    <p:growl id="messages" showDetail="true" />
     <p:fileUpload value="#{fileUploadView1.file}" mode="simple"/>
     <p:commandButton value="Submit" ajax="false" actionListener="#{fileUploadView1.upload}" />
</h:form>

文件控制器：

   @ManagedBean
@SessionScoped
public class FileController1 {

    private FileDbUtil1 fileDbUtil;
    private Logger logger = Logger.getLogger(getClass().getName());

    public FileController1() throws Exception {

        fileDbUtil = FileDbUtil1.getInstance();
    }
    public String uploadFile(UploadedFile theFile) {

        logger.info("Uploading File: " + theFile);

        try {
            fileDbUtil.uploadFile(theFile);
               } catch (Exception exc) {
            logger.log(Level.SEVERE, "Error adding files", exc);

            addErrorMessage(exc);
            return null;
        }
        return "welcomePrimefaces";
    }



        private void addErrorMessage(Exception exc) {
        FacesMessage message = new FacesMessage("Error: " + exc.getMessage());
        FacesContext.getCurrentInstance().addMessage(null, message);
    }



}

FileDbUtil文件

 public static FileDbUtil1 getInstance() throws Exception {
        if (instance == null) {
            instance = new FileDbUtil1();
        }

        return instance;
    }

    private FileDbUtil1() throws Exception {
        dataSource = getDataSource();
    }

    private DataSource getDataSource() throws NamingException {
        Context context = new InitialContext();

        DataSource theDataSource = (DataSource) context.lookup(jndiName);

        return theDataSource;
    }

    public void uploadFile(UploadedFile theFile) throws Exception {
        fileName = theFile.getFileName();
        input = theFile.getInputstream();


       Connection myConn = null;
        PreparedStatement myStmt = null;

        try {
            myConn = getConnection();

            String sql = "insert into  upload"
                    + "(name, file)"
                    + " values (?,?)";

            myStmt = myConn.prepareStatement(sql);

            // set params
            myStmt.setString(1, fileName);
            myStmt.setBinaryStream(2, input);

            myStmt.executeUpdate();
        } finally {
            close(myConn, myStmt);
        }

    }



    private Connection getConnection() throws Exception {

        Connection theConn = dataSource.getConnection();

        return theConn;
    }

    private void close(Connection theConn, Statement theStmt) {
        close(theConn, theStmt, null);
    }

    private void close(Connection theConn, Statement theStmt, ResultSet theRs) {

        try {
            if (theRs != null) {
                theRs.close();
            }

            if (theStmt != null) {
                theStmt.close();
            }

            if (theConn != null) {
                theConn.close();
            }

        } catch (Exception exc) {
            exc.printStackTrace();
        }
    }
}

堆栈跟踪：注意，我可以在调用helper类之前打印文件大小

  Info:   filesize 3501
Info:   filesize3 3501
Warning:   java.lang.NullPointerException
javax.el.ELException: java.lang.NullPointerException
    at com.sun.el.parser.AstValue.invoke(AstValue.java:293)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:814)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at com.uploadfile.test.FileUploadView1.upload(FileUploadView1.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    ... 39 more

FATAL:   JSF1073: javax.faces.FacesException caught during processing of INVOKE_APPLICATION 5 : UIComponent-ClientId=, Message=java.lang.NullPointerException
FATAL:   java.lang.NullPointerException
javax.faces.FacesException: java.lang.NullPointerException
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:89)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.el.ELException: java.lang.NullPointerException
    at com.sun.el.parser.AstValue.invoke(AstValue.java:293)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:814)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    ... 31 more
Caused by: java.lang.NullPointerException
    at com.uploadfile.test.FileUploadView1.upload(FileUploadView1.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    ... 39 more

原因：java.lang.NullPointerException 位于com.uploadfile.test.FileUploadView1.upload（FileUploadView1.java:68）

fileController没有被注入

使用@Inject private FileController1 fileController

---

巴卢斯的评论是对的。

确实有很多错误，基本上需要完全重写（我建议根据一本像样的Java/JSF/JavaEE书籍学习基础知识）。但最重要的一步，用DB保存文件的指令，在目前发布的代码中还看不到。在哪里调用

uploadFile（）

以将文件保存到数据库中？我希望看到它在

fileUploadListener（）

中被调用，当文件进入时立即调用。更新了问题，注意，我正在呼叫FileController并传递上传的文件。你能看一下吗？对不起，到目前为止所有这些错误都与“将上传的文件存储在数据库中”无关。此外，您现在基本上是在问“为什么我得到一个NullPointerException？”而不是“为什么变量X为null？”，指出了特定的变量。这并没有显示出对基本Java的最低理解。我建议你爬出Java EE的深坑，让项目保持原样，花上几周时间仔细阅读一本像样的Java SE书籍/教程。谢谢，我让它工作起来了。即使是我一开始也不喜欢你坚持说我需要找出原因，而不是告诉我怎么做，但至少今天我学到了一些东西。谢谢你的帮助！！！用你的建议更新了问题。我仍然有空异常，请查看更新的堆栈。

  Info:   filesize 3501
Info:   filesize3 3501
Warning:   java.lang.NullPointerException
javax.el.ELException: java.lang.NullPointerException
    at com.sun.el.parser.AstValue.invoke(AstValue.java:293)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:814)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at com.uploadfile.test.FileUploadView1.upload(FileUploadView1.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    ... 39 more

FATAL:   JSF1073: javax.faces.FacesException caught during processing of INVOKE_APPLICATION 5 : UIComponent-ClientId=, Message=java.lang.NullPointerException
FATAL:   java.lang.NullPointerException
javax.faces.FacesException: java.lang.NullPointerException
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:89)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.el.ELException: java.lang.NullPointerException
    at com.sun.el.parser.AstValue.invoke(AstValue.java:293)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:814)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    ... 31 more
Caused by: java.lang.NullPointerException
    at com.uploadfile.test.FileUploadView1.upload(FileUploadView1.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:289)
    ... 39 more