Question

我一直得到image == null！从服务器。我只是试图显示我从fileinputstream上传到mysql的图像作为blob。在数据库中，它显示为bufferedinputstream fyi。我硬编码，看看我是否能得到一个结果。你们能看到我做错了吗？

@Path("/photo" )
public class DisplayPhoto { 

@GET
@Path("{id}")
 @Produces("image/*")
public Response post(@PathParam("id") String id) {
    Connection con = connection();

    BufferedImage image = null;
    try {
        image = ImageIO.read( getPhoto(con).getBinaryStream() );
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }



    ByteArrayOutputStream baos2 = new ByteArrayOutputStream();

    try {
        ImageIO.write( image, "jpg", baos2 );
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }




    return Response.ok(baos2.toByteArray()).build();

}



public Connection connection(){
    Connection con = null;

    try {// set up driver for database
        Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }


    try {
        con = DriverManager.getConnection("jdbc:mysql://aa1c9da17owdhky.cotr7twg0ekb.us-west-2.rds.amazonaws.com/test","nightskycode","uocb4t111");
    //  boolean reachable = con.isValid(10);// check for connection to DB


    } catch (SQLException e) {
        e.printStackTrace();
        System.out.println("No go!3");
    }
    return con;
  }

public Blob getPhoto(Connection con){

    Blob photo = null;
    Statement stmt = null;
    ResultSet rs = null;


    try {
        stmt = con.createStatement();
        rs = stmt.executeQuery("Select photo from photos where photo_id = 3");

        if (stmt.execute("Select photo from photos where photo_id = 3")) {
            rs = stmt.getResultSet();

            while (rs.next()) { // results here
           photo =  rs.getBlob("photo");
            System.out.println(rs.getString("photo")); }

        }

    } 
    catch (SQLException ex){
        // handle any errors
        System.out.println("SQLException: " + ex.getMessage());
        System.out.println("SQLState: " + ex.getSQLState());
        System.out.println("VendorError: " + ex.getErrorCode());
    }
    return photo;

}






**here is the trace**

Dec 22, 2013 9:29:35 PM org.apache.catalina.core.StandardWrapperValve invoke

SEVERE：servlet [ServletAdaptor]的Servlet.service（）在路径[/ restService]的上下文中引发了异常 java.lang.IllegalArgumentException：image == null！ at javax.imageio.ImageTypeSpecifier.createFromRenderedImage（Unknown Source）在javax.imageio.ImageIO.getWriter（未知来源）在javax.imageio.ImageIO.write（未知来源） at restService.status.DisplayPhoto.post（DisplayPhoto.java:63） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（Unknown Source） at sun.reflect.DelegatingMethodAccessorImpl.invoke（Unknown Source） at java.lang.reflect.Method.invoke（Unknown Source） at com.sun.jersey.spi.container.JavaMethodInvokerFactory $ 1.invoke（JavaMethodInvokerFactory.java:60） at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider $ ResponseOutInvoker._dispatch（AbstractResourceMethodDispatchProvider.java:205） at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch（ResourceJavaMethodDispatcher.java:75）在com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept（HttpMethodRule.java:302）在com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept（RightHandPathRule.java:147）在com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept（ResourceClassRule.java:108）在com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept（RightHandPathRule.java:147） at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept（RootResourceClassesRule.java:84） at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest（WebApplicationImpl.java:1542） at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest（WebApplicationImpl.java:1473） at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest（WebApplicationImpl.java:1419） at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest（WebApplicationImpl.java:1409）在com.sun.jersey.spi.container.servlet.WebComponent.service（WebComponent.java:409）在com.sun.jersey.spi.container.servlet.ServletContainer.service（ServletContainer.java:540）在com.sun.jersey.spi.container.servlet.ServletContainer.service（ServletContainer.java:715）在javax.servlet.http.HttpServlet.service（HttpServlet.java:722）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:304）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:240）在org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:164）在org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:462）在org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:164） at org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:100）在org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:562）在org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:118）在org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:395）在org.apache.coyote.http11.Http11Processor.process（Http11Processor.java:250）在org.apache.coyote.http11.Http11Protocol $ Http11ConnectionHandler.process（Http11Protocol.java:188） at org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run（JIoEndpoint.java:302） at java.util.concurrent.ThreadPoolExecutor.runWorker（Unknown Source） at java.util.concurrent.ThreadPoolExecutor $ Worker.run（Unknown Source）在java.lang.Thread.run（未知来源）

在浏览器中使用泽西显示Blob

0 个答案: