spring boot打包成war包的页面该放到哪里？

背景

经常有朋友问我，平时都是使用spring mvc，打包成war包发布到tomcat上，如何快速到切换到spring boot的war或者jar包上？

先来看看传统的war包样式是什么样子的？

1. 传统的spring MVC格式的war包

可以看到，webapp/resouces文件存放css/js/html等静态文件，WEB-INF存放jsp动态文件。

对应的配置文件

@EnableWebMvc //mvc:annotation-driven
@Configuration
@ComponentScan({ "com.xxx.web" })
public class SpringWebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
    }

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

}

对应xml的配置如下：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd ">

    <context:component-scan base-package="com.xxxx.web" />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="prefix" value="/WEB-INF/views/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

    <mvc:resources mapping="/resources/**" location="/resources/" />

    <mvc:annotation-driven />

</beans>

2.spring boot格式的jar包

jar的结构，spring 尽量避免jsp的动态文件，而是使用如Thymeleaf 、FreeMarker等模板引擎，因为jsp有很多限制。

28.4.5 JSP Limitations

When running a Spring Boot application that uses an embedded servlet container (and is packaged as an executable archive), there are some limitations in the JSP support.

With Jetty and Tomcat, it should work if you use war packaging. An executable war will work when launched with java -jar, and will also be deployable to any standard container. JSPs are not supported when using an executable jar.

Undertow does not support JSPs.

Creating a custom error.jsp page does not override the default view for error handling. Custom error pages should be used instead.

3.spring boot 格式的war包

如何切换？

其实，通过上面的结构，我们可以看出，spring boot的标准规格还是不建议使用jsp的，推荐使用Thymeleaf 、FreeMarker等模板引擎，然后所有的静态文件同样存储在resources下面，可以使用代码配置动态代码

@Configuration
@EnableWebMvc
public class SpringConfig
{
    @Bean
    public InternalResourceViewResolver viewResolver()
    {
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setPrefix("/WEB-INF/view/");
        viewResolver.setSuffix(".jsp");

        return viewResolver;
    }
}

或者静态属性配置

spring.mvc.static-path-pattern=/resources/**

来自定义配置。

也可以使用静态文件动态化

spring.resources.chain.strategy.content.enabled=true
spring.resources.chain.strategy.content.paths=/**
spring.resources.chain.strategy.fixed.enabled=true
spring.resources.chain.strategy.fixed.paths=/js/lib/
spring.resources.chain.strategy.fixed.version=v12

注意：centos下使用tomcat时，编译的jsp文件，上传的文件等等默认都存储在临时目录里，会

If you choose to use Tomcat on centos， be aware that, by default, a temporary directory is used to store compiled JSPs, file uploads, and so on. This directory may be deleted by tmpwatch while your application is running, leading to failures. To avoid this behavior, you may want to customize your tmpwatch configuration such that tomcat.* directories are not deleted or configure server.tomcat.basedir such that embedded Tomcat uses a different location.

参考资料

【1】https://www.mkyong.com/spring-boot/spring-boot-deploy-war-file-to-tomcat/

【2】https://www.baeldung.com/spring-boot-war-tomcat-deploy

【3】https://docs.spring.io/spring-boot/docs/2.1.2.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-static-content