Spring JDBC NullPointerException on INSERT Statement

Question

I'm working on a Maven, Spring-Boot, Vaadin Project and i can not resolve a NullPointerException when i try to create a new entity in my university table.

I creating a new View and bind all together but if i want to execute my saveUniversity() function with the example values it always throws a NullPointerException. Hope this is all relevant code.

AddUniversityView.java

public class AddUniversityView extends VerticalLayout {

private TextField name = new TextField("Name");
private TextField city = new TextField("City");
private TextField country = new TextField("Country");

private Button save = new Button("Save", e -> saveUniversity()); // Line 23

Binder<University> binder = new Binder<>();

private University university = new University();

@Autowired
private UniversityService universityService;

public AddUniversityView() {

    add(name, city, country, save);



    /**
     * Some values for example
     */
    name.setValue("LMU");
    city.setValue("Muenchen");
    country.setValue("Deutschland"); 


    binder.bind(name, University::getName, University::setName);
    binder.bind(city, University::getCity, University::setCity);
    binder.bind(country, University::getCountry, University::setCountry);
}

public void saveUniversity() {
    binder.setBean(university);
    System.out.println(binder.getBean().toString());
    universityService.create(university); // Line 109
    clearFields();
}

public void clearFields() {
    binder.readBean(null);
}

UniversityService

@Service
public class UniversityService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void create(University university) {
        jdbcTemplate.update("INSERT INTO university (name, city, country) VALUES (?, ?, ?)", 
                university.getName(), university.getCity(), university.getCountry());
    }
}

application.properties

spring.datasource.url:jdbc:mysql://localhost/univers
spring.datasource.username=user
spring.datasource.password=password
spring.datasource.driverClassName=com.mysql.jdbc.Driver

univers Database

+-------------------+
| Tables_in_univers |
+-------------------+
| student           |
| university        |
+-------------------+

university column

+---------+-------------+------+-----+---------+----------------+
| Field   | Type        | Null | Key | Default | Extra          |
+---------+-------------+------+-----+---------+----------------+
| id      | int(11)     | NO   | PRI | NULL    | auto_increment |
| name    | varchar(45) | NO   |     | NULL    |                |
| city    | varchar(45) | NO   |     | NULL    |                |
| country | varchar(45) | NO   |     | NULL    |                |
+---------+-------------+------+-----+---------+----------------+

Error

java.lang.NullPointerException: null
    at com.sandrofriedrich.ui.views.university.AddUniversityView.saveUniversity(AddUniversityView.java:109) ~[classes/:na]
    at com.sandrofriedrich.ui.views.university.AddUniversityView.lambda$0(AddUniversityView.java:23) ~[classes/:na]
    at com.vaadin.flow.component.ComponentEventBus.fireEvent(ComponentEventBus.java:133) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.component.ComponentEventBus.handleDomEvent(ComponentEventBus.java:327) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.component.ComponentEventBus.lambda$addDomTrigger$5ee67f2b$1(ComponentEventBus.java:191) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.internal.nodefeature.ElementListenerMap.lambda$fireEvent$2(ElementListenerMap.java:379) ~[flow-server-1.0.5.jar:na]
    at java.util.ArrayList.forEach(ArrayList.java:1257) ~[na:1.8.0_181]
    at com.vaadin.flow.internal.nodefeature.ElementListenerMap.fireEvent(ElementListenerMap.java:379) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.rpc.EventRpcHandler.handleNode(EventRpcHandler.java:59) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.rpc.AbstractRpcInvocationHandler.handle(AbstractRpcInvocationHandler.java:64) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocationData(ServerRpcHandler.java:377) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.ServerRpcHandler.lambda$handleInvocations$0(ServerRpcHandler.java:367) ~[flow-server-1.0.5.jar:na]
    at java.util.ArrayList.forEach(ArrayList.java:1257) ~[na:1.8.0_181]
    at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:367) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:309) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:89) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1486) ~[flow-server-1.0.5.jar:na]
    at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:300) [flow-server-1.0.5.jar:na]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:356) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) [spring-webmvc-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.9.RELEASE.jar:5.0.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_181]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_181]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.34.jar:8.5.34]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]

Assuming `universityService.create(university);` is really the line 109, did you try to run the debugger and check if `universityService` is `null`, and if so why? — mystarrocks, Nov 05 '18 at 16:35

score 0 · Accepted Answer · answered Nov 06 '18 at 07:43

0

How do you create the AddUniversityView?

If it's used with a @Route annotation, or if it is also autowired in some other class, it should work.

However, if you instantiate it yourself, as in new AddUniversityView(), autowiring will not work.

answered Nov 06 '18 at 07:43

Erik Lumme

5,202
13
27

thank you this worked for me – cyflex Nov 06 '18 at 11:10

score -1 · Answer 2 · answered Nov 06 '18 at 07:56

-1

@Autowired means, somebody from outside will set this field. "Private" on the other hand means nobody except this class is allowed to use it.

You should change your code like this

@Autowired
UniversityService universityService;

Hope this help!

answered Nov 06 '18 at 07:56

David Pham

1,673
19
17

Spring is perfectly capable of autowiring `private` fields. – M. Deinum Nov 06 '18 at 07:57