Vaadin + Spring集成：空指针异常 [英] Vaadin + Spring Integration: Null Pointer exception

问题描述

  @SuppressWarnings（serial）
我有一个Vaadin web应用程序@Theme（mytheme）
公共类LogsUI扩展UI {
 
 LogsView logsViewer = new LogsView（）; 
 
 @WebServlet（value =/ *，asyncSupported = true）
 @VaadinServletConfiguration（productionMode = false，ui = LogsUI.class）
 public static class Servlet extends VaadinServlet { 
} 
 
 @Override 
 protected void init（VaadinRequest request）{
 Panel panel = new Panel（）; 
 panel.setContent（logsViewer）; 
 panel.setSizeFull（）; 
 setContent（panel）; 
 
 
 
 
 $ b $ p 
 $ b你可以看到我添加使用 setContent 添加LogsView类，它是一个视图 - 它是一个声明的片段：
  @SuppressWarnings（serial）
公共类LogsView扩展CustomComponent implements视图{
 
 //一些变量，按钮，组件等
 ProcessDao processDao; 
 
 
 //示例方法
 void sampleMethod（）{
 processDao = new ProcesDao; 
 processDao.getAllprocesses（）; //只是示例，不管逻辑如何
} 
 
} 
  
 My  ProcessDao  class： 
 
 
  public class ProcessDao {
 
 
 @Autowired 
 ApplicationConfiguration applicationConfiguration; 
 
 public ProcessDao（）{
} 
 
 
 public List< ProcessEntity> getAllProcess（）{
 System.out.println（TEST：+ applicationConfiguration）; 
 
 //实体管理器和其他东西
 
 return processList; 
 
 
 $ / code $ / pre 
 
你可以看到我做了code > System.out.println（）来检查是否获取 applicationConfiguration 对象。我得到空。这是主要问题。 
 
 
 
这是我的ApplicationConfiguration类： 
 
 
  @Configuration 
 @EnableTransactionManagement 
 @ComponentScan（basePackages = {com.sample.project}）
 @PropertySource（{classpath：jpa.postgresql.properties，classpath：hibernate.properties}）
 @EnableJpaRepositories（basePackages = {com.sample.project.repo}）
 public class ApplicationConfiguration扩展WebMvcConfigurerAdapter {
 
 @Value（$ {javax.persistence.jdbc。驱动程序}）
私人字符串driverClassName; 
 
 @Value（$ {javax.persistence.jdbc.url}）
 private String databaseUrl; 
 
 @Value（$ {javax.persistence.jdbc.user}）
 private String databaseUser; 
 
 @Value（$ {javax.persistence.jdbc.password}）
 private String databasePassword; 
 
 @Value（$ {hibernate.dialect}）
 private String方言; 
 
 @Value（$ {hibernate.show_sql}）
 private boolean showSQL; 
 
 @Value（$ {hibernate.hbm2ddl.auto}）
 private String hbm2ddlAuto; 
 
 @Bean 
 public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer（）{
 return new PropertySourcesPlaceholderConfigurer（）; 
 
 
 $Be 
 @PersistenceContext 
 LocalContainerEntityManagerFactoryBean entityManagerFactory（）{
 LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean（）; 
 entityManagerFactoryBean.setDataSource（dataSource（））; 
 entityManagerFactoryBean.setPersistenceProviderClass（HibernatePersistenceProvider.class）; 
 entityManagerFactoryBean.setJpaProperties（hibernateJPAProperties（））; 
 entityManagerFactoryBean.setPackagesToScan（com.sample.project）; 
返回entityManagerFactoryBean; 
 
 
 @Bean 
 public DataSource dataSource（）{
 DriverManagerDataSource dataSource = new DriverManagerDataSource（）; 
 dataSource.setDriverClassName（driverClassName）; 
 dataSource.setUrl（databaseUrl）; 
 dataSource.setUsername（databaseUser）; 
 dataSource.setPassword（databasePassword）; 
返回dataSource; 
 
 $ b $公共属性hibernateJPAProperties（）{
属性properties = new Properties（）; 
 properties.put（hibernate.dialect，方言）; 
 properties.put（hibernate.show_sql，showSQL）; 
 properties.put（hibernate.hbm2ddl.auto，hbm2ddlAuto）; 
返回属性; 
 
 
 $Be 
 public JpaTransactionManager transactionManager（）{
 JpaTransactionManager transactionManager = new JpaTransactionManager（）; 
 transactionManager.setEntityManagerFactory（entityManagerFactory（）。getObject（））; 
返回transactionManager; 
 
 
an 
 public FinancialProcessEntityDao financialProcessEntityDao（）{
 FinancialProcessEntityDao dao = new FinancialProcessEntityDao（）; 
返回dao; 
 
 
 @Override 
 public void configureDefaultServletHandling（DefaultServletHandlerConfigurer configurer）{
 configurer.enable（）; 
} 
 
} 
  
我缺少什么吗？如何正确整合我的Vaadin应用程序与Spring？
解决方案
您应该试试这个：
 
 
  processDao = WebApplicationContextUtils.getRequiredWebApplicationContext（
 VaadinServlet.getCurrent（）。getServletContext（））。getBean（IProcessDao.class）; 
  
你可以在这里找到一些描述：链接 
 
I have a Vaadin web application with UI class like this:
@SuppressWarnings("serial")
@Theme("mytheme")
public class LogsUI extends UI {

LogsView logsViewer = new LogsView();

@WebServlet(value = "/*", asyncSupported = true)
@VaadinServletConfiguration(productionMode = false, ui = LogsUI.class)
public static class Servlet extends VaadinServlet {
}

@Override
protected void init(VaadinRequest request) {
    Panel panel = new Panel();
    panel.setContent(logsViewer);
    panel.setSizeFull();
    setContent(panel);
}
}
As u can see i add use setContent to add LogsView class which is a view - it is a fragment of declaration:
@SuppressWarnings("serial")
public class LogsView extends CustomComponent implements View {

//some variables, buttons, components etc
ProcessDao processDao;


//sample method
void sampleMethod(){
      processDao = new ProcesDao;
      processDao.getAllprocesses(); //just sample, no matter about logic
}

}
My ProcessDao class:
public class ProcessDao {


@Autowired
ApplicationConfiguration applicationConfiguration;

public ProcessDao() {
}


public List<ProcessEntity> getAllProcess(){
    System.out.println("TEST:" + applicationConfiguration);

    //entity manager and other stuffs

     return processList;
}
}
As u can see i did System.out.println() to check if im getting applicationConfiguration object. Im getting null. This is main problem. 

this is my ApplicationConfiguration class:
@Configuration
@EnableTransactionManagement
@ComponentScan(basePackages = {"com.sample.project"})
@PropertySource({"classpath:jpa.postgresql.properties", "classpath:hibernate.properties"})
@EnableJpaRepositories(basePackages = {"com.sample.project.repo"})
public class ApplicationConfiguration extends WebMvcConfigurerAdapter {

@Value("${javax.persistence.jdbc.driver}")
private String driverClassName;

@Value("${javax.persistence.jdbc.url}")
private String databaseUrl;

@Value("${javax.persistence.jdbc.user}")
private String databaseUser;

@Value("${javax.persistence.jdbc.password}")
private String databasePassword;

@Value("${hibernate.dialect}")
private String dialect;

@Value("${hibernate.show_sql}")
private boolean showSQL;

@Value("${hibernate.hbm2ddl.auto}")
private String hbm2ddlAuto;

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
    return new PropertySourcesPlaceholderConfigurer();
}

@Bean
@PersistenceContext
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
    LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
    entityManagerFactoryBean.setDataSource(dataSource());
    entityManagerFactoryBean.setPersistenceProviderClass(HibernatePersistenceProvider.class);
    entityManagerFactoryBean.setJpaProperties(hibernateJPAProperties());
    entityManagerFactoryBean.setPackagesToScan("com.sample.project");
    return entityManagerFactoryBean;
}

@Bean
public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName(driverClassName);
    dataSource.setUrl(databaseUrl);
    dataSource.setUsername(databaseUser);
    dataSource.setPassword(databasePassword);
    return dataSource;
}

public Properties hibernateJPAProperties() {
    Properties properties = new Properties();
    properties.put("hibernate.dialect", dialect);
    properties.put("hibernate.show_sql", showSQL);
    properties.put("hibernate.hbm2ddl.auto", hbm2ddlAuto);
    return properties;
}

@Bean
public JpaTransactionManager transactionManager() {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
    return transactionManager;
}

@Bean
public FinancialProcessEntityDao financialProcessEntityDao() {
    FinancialProcessEntityDao dao = new FinancialProcessEntityDao();
    return dao;
}

@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
}

}
Am i something missing? How to properly integrate my Vaadin app with Spring?
解决方案
You should try this:
processDao = WebApplicationContextUtils.getRequiredWebApplicationContext(
    VaadinServlet.getCurrent().getServletContext()).getBean(IProcessDao.class);
You can find some description here: link

                        
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