Spring Boot无法解析JSP中的模型数据[重复]答案

【问题标题】：Spring Boot not able to parse model data in JSP [duplicate]Spring Boot无法解析JSP中的模型数据[重复]
【发布时间】：2020-10-22 08:44:21
【问题描述】：

我有一个简单的JSPwebapp，它应该在页面上显示Hello World，但由于某种原因，model 数据未被解析。

浏览器上的实际输出： Hello ${name}!

浏览器上的预期输出： Hello World!

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.howtodoinjava</groupId>
    <artifactId>spring-boot-demo</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-demo Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
    </parent>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!-- Web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Tomcat Embed -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <!-- JSTL -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>
        <!-- To compile JSP files -->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

IndexController.java

@Controller
public class IndexController {

    @GetMapping({"/", "/hello"})
    public String hello(Model model, @RequestParam(value = "name", required = false, defaultValue = "World") String name) {
        model.addAttribute("name", name);
        return "hello";
    }

}

MvcConfiguration.java

@Configuration
@EnableWebMvc
@ComponentScan
public class MvcConfiguration extends WebMvcConfigurerAdapter {

    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/view/");
        resolver.setSuffix(".jsp");
        resolver.setViewClass(JstlView.class);
        registry.viewResolver(resolver);
    }

}

SpringBootWebApplication.java

@SpringBootApplication
public class SpringBootWebApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(SpringBootWebApplication.class);
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(SpringBootWebApplication.class, args);
    }
}

application.properties

spring.mvc.view.prefix=/WEB-INF/view/
spring.mvc.view.suffix=.jsp

WEB-INF/view/hello.jsp

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Hello ${name}!</title>
    </head>
    <body>
        <h2 class="hello-title">Hello ${name}!</h2>
    </body>
</html>

web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
</web-app>

【问题讨论】：

我没有检查你的配置，但据我记得你使用了错误的语法
Hello
在页面顶部添加<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>并更改为<c:out value="${name}"></c:out>但仍然没有运气

标签： java spring-boot jsp tomcat jstl

【解决方案1】：

通过将包类型从 war 更改为 jar 并更改一些代码来使其工作。见下文。

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.howtodoinjava</groupId>
    <artifactId>spring-boot-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-demo Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
        </dependency>
    </dependencies>

</project>

SpringBootWebApplication.java

@SpringBootApplication
public class SpringBootWebApplication {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(SpringBootWebApplication.class, args);
    }

}

hello.jsp

<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Hello ${name}!</title>
    </head>
    <body>
        <h2 class="hello-title">Hello ${name}!</h2>
    </body>
</html>

MvcConfiguration.java（已删除）

现在浏览器中的实际输出： Hello World!

【讨论】：