Question

我是java spring框架的新手，我试图在启动时调用方法或初始化方法，所以当应用程序启动时，我将能够在jsp页面上看到数据库中的数据。我试过@EventListener，@ PostConstruct，但没有什么对我有用。

这是我的WebConfigura类

@Configuration
@ComponentScan("com.store.spring")
@EnableWebMvc
public class WebConfiguration extends WebMvcConfigurerAdapter {

@Bean
public DataSource dataSource() {
    final JndiDataSourceLookup lookup = new JndiDataSourceLookup();
    lookup.setResourceRef(true);
    DataSource dataSource = lookup.getDataSource("jdbc/product_db");

    return dataSource;
}

@Bean
public UrlBasedViewResolver resolver() {
    UrlBasedViewResolver viewResolver = new UrlBasedViewResolver();
    viewResolver.setPrefix("/WEB-INF/views/");
    viewResolver.setSuffix(".jsp");
    viewResolver.setViewClass(JstlView.class);

    return viewResolver;
}

@Override
public void addViewControllers(ViewControllerRegistry registry) {
    registry.addViewController("/").setViewName("index");
}

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/resource/css/**").addResourceLocations("/css/").setCachePeriod(31556926);
}

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

@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(new HeaderInterceptor());
}
}

这是Web Application Initializer类

@Component
public class WebInitializer implements WebApplicationInitializer {

@Override
public void onStartup(ServletContext servletContext) throws ServletException {
    AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
    context.register(WebConfiguration.class);
    // Add context.setCongiglocation("/WEB-INF/spring/dispatcher-config.xml");

    ServletRegistration.Dynamic registration = servletContext.addServlet("dispatcher", new DispatcherServlet(context));
    registration.addMapping("/");
    registration.setLoadOnStartup(1);

    ContextLoaderListener listener = new ContextLoaderListener(context);
    servletContext.addListener(listener);
}
}

这是控制器类

@Controller
public class ProductController {

@Autowired
private ProductService productService;

@RequestMapping("/index")
public String index(Model model) {
    List<Product> listProduct = productService.getPrducts();
    model.addAttribute("listProduct", listProduct);

    return "index";
}

// Request mapping using SQL tag
@RequestMapping("/location")
public String addLocation(Model model) {
    List<Product> listProduct = productService.getPrducts();
    model.addAttribute("listProduct", listProduct);

    return "location";
}

@RequestMapping("/entry")
public String entry() {
    return "Entry";
}

@RequestMapping("/aboutUs")
public String aboutUS() {return "AboutUs";}

@RequestMapping("/deal")
public String deal() {
    return "Deal";
}

@RequestMapping("/listProduct")
public String listOrganizationService(Model model) {
    List<Product> listProduct = productService.getPrducts();
    model.addAttribute("listProduct", listProduct);

    return "ListOrganizations";
}
}

这是标头拦截器类

public class HeaderInterceptor extends HandlerInterceptorAdapter {

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
        throws Exception {
    request.setAttribute("title", "We hope you have a scary and fun filled halloween");
    String location = request.getParameter("locationName");
    if (location != null) {
        request.setAttribute("locationName", location);
    }
    return true;
}
}

这是我想要初始化或启动时调用的方法。或至少有些事情接近这个

@RequestMapping("/index")
public String index(Model model) {
List<Product> listProduct = productService.getPrducts();
model.addAttribute("listProduct", listProduct);

return "index";
}

我正在使用index.jsp调用listProduct来打印我的数据。请注意，index.jsp是应用程序启动时调用的第一个jsp。我希望它能够自动打印出这些数据

<div class="main-container" style="text-align: center">
<c:forEach var="row" items="${listProduct}">
    <div class="detail">
        <td>ID: <c:out value="${row.id}"></c:out></td>
        <br/>
        <td>Name: <c:out value="${row.productName}"></c:out></td>
        <br/>
        <td>Quantity: <c:out value="${row.quantity}"></c:out></td>
        <br/>
        <td>Price: <c:out value="${row.price}"></c:out></td>
        <br/>
        <td><div class="few-line"><c:out value="${row.description}"></c:out></div></td>
    </div>
</c:forEach>

我希望有人可以帮助我。

例如，我的WebInitializer类中包含此代码，当我运行它时出现错误消息

@EventListener(ContextRefreshedEvent.class)
public void contextRefreshedEvent(Model model) {
    List<Product> productList = productService.getPrducts();
    model.addAttribute("productList", productList)
}

引起：java.lang.IllegalArgumentException：参数类型不匹配       at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）       at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）       at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）       at java.lang.reflect.Method.invoke（Method.java:498）       在org.springframework.context.event.ApplicationListenerMethodAdapter.doInvoke（ApplicationListenerMethodAdapter.java:256）       ......还有56个   org.apache.catalina.core.StandardContext.startInternal一个或多个   听众未能开始。   org.apache.catalina.core.StandardContext.startInternal Context []   由于先前的错误，启动失败   org.springframework.web.context.support.AnnotationConfigWebApplicationContext.doClose   关闭Root WebApplicationContext：启动日期[Sun Aug 13 10:43:51   EDT 2017];上下文层次结构的根

这些是我的jar的插件和依赖项

<build>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.6.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
        <plugin>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.0.0</version>
            <configuration>
                <warSourceDirectory>WebContent</warSourceDirectory>
            </configuration>
        </plugin>
    </plugins>
</build>
<dependencies>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/jstl/jstl -->
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>6.0.6</version>
    </dependency>
    <dependency>
        <groupId>commons-dbcp</groupId>
        <artifactId>commons-dbcp</artifactId>
        <version>1.4</version>
    </dependency>
</dependencies>

Answer 1

Java Spring初始化，在启动时调用方法

你可以用Artist注释一个Spring bean的方法，让Spring在构造之后调用它。您还可以使用@PostConstruct注释一个方法，以便在构造该bean期间让Spring调用它。我们通常使用其中一个来在启动时调用方法，例如将数据从数据库加载到缓存中。

Java Spring初始化，在启动时调用方法

1 个答案: