Question

遵循了几个例子，仍然无法使其发挥作用。

使用基本的Spring MVC，尝试显示控制器返回的一些数据。（使用Spring 4.3.9，Tomcat 8.5.20和Chromium）

这是项目树：

package mywebapp.config;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class MyWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected String[] getServletMappings() {
        return new String[] { "/" };
    }

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[] { RootConfig.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[] { WebConfig.class };
    }
}

1）MyWebAppInitializer.java

package mywebapp.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.UrlBasedViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan("mywebapp.config")
public class WebConfig extends WebMvcConfigurerAdapter {

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

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

2）RootConfig.java是一个空类，没有bean。

3）WebConfig.java - 我使用了这个配置文件的两个版本： 版本A：

package mywebapp.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.UrlBasedViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc
@ComponentScan("mywebapp.config")
public class WebConfig extends WebMvcConfigurerAdapter {

    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        return resolver;
    }

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

版本B： - 区别仅在于viewResolver（）

package mywebapp.web;
import static org.springframework.web.bind.annotation.RequestMethod.*;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.ui.ModelMap;

@Controller
public class HomeController {
    @RequestMapping(value="/", method=GET)
    public String home(ModelMap model) {
    model.addAttribute("xyz","this is my message");
        return "home";
    }
}

4）HomeController.java

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<html>
<body>
<h2>Hello World!</h2>
<c:out value="${xyz}" />
<br>${xyz}
</body>
</html>

5）home.jsp

WebConfig.java

6）web.xml - ＆＃34;空＆＃34;，在被maven原型创建后未被修改。

对于Hello World! ${xyz} ${xyz}的两个版本，输出是相同的：

{{1}}

请帮忙！

Answer 1

两步解决方案：

A）删除由maven原型创建的web.xml。

B）将以下maven插件添加到pom.xml：

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.0.0</version>
        </plugin>
    </plugins>
</build>

无法使JSP显示模型值。简单的Spring MVC示例

1 个答案: