SpringBoot jsp詳解

簡單使用springboot建立工程

版本：1.5.8

開發工具：idea 2017.1.4

spring-boot 對模板引擎的支持有：

• FreeMarker
• Groovy
• Thymeleaf
• Mustache
• JSP

可是官方不建議實用jsp：

JSPs should be avoided if possible, there are several known limitations when using them with embedded servlet containers.

而且實用jsp時會有限制，須要特殊配置。可是既然支持jsp，因此就專門針對jsp作一下demo。

個人項目結構以下圖：

 

而後看一下pom文件：

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <parent>
      <groupId>com.songhaiqiang.springboot-example</groupId>
      <artifactId>springboot-parent</artifactId>
      <version>1.0-SNAPSHOT</version>
   </parent>
   <groupId>com.songhaiqiang.springboot.web.jsp</groupId>
   <artifactId>springboot-web-jsp</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>war</packaging>

   <name>springboot-web-jsp</name>
   <description>Demo project for Spring Boot</description>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
      <java.version>1.8</java.version>
   </properties>

   <dependencies>
      <!-- Compile -->
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <dependency>
         <groupId>javax.servlet</groupId>
         <artifactId>jstl</artifactId>
      </dependency>
      <!-- Provided -->
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-tomcat</artifactId>
         <!--<scope>provided</scope>-->
      </dependency>
      <dependency>
         <groupId>org.apache.tomcat.embed</groupId>
         <artifactId>tomcat-embed-jasper</artifactId>
         <scope>provided</scope>
      </dependency>
      <!-- Test -->
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
               <useSystemClassLoader>false</useSystemClassLoader>
            </configuration>
         </plugin>
      </plugins>
   </build>
   <profiles>
      <profile>
         <id>java8</id>
         <activation>
            <jdk>8</jdk>
         </activation>
         <build>
            <plugins>
               <plugin>
                  <groupId>org.apache.maven.plugins</groupId>
                  <artifactId>maven-surefire-plugin</artifactId>
                  <configuration>
                     <skipTests>true</skipTests>
                  </configuration>
               </plugin>
            </plugins>
         </build>
      </profile>
   </profiles>
</project> 

這裏須要注意的是加上如下依賴：

<dependency>
   <groupId>org.apache.tomcat.embed</groupId>
   <artifactId>tomcat-embed-jasper</artifactId>
   <scope>provided</scope>
</dependency>

而且package個格式不能爲jar 必定要爲war.

 

二、application.properties須要加入的是

server.port=80
server.address=localhost
spring.mvc.view.prefix=/WEB-INF/jsp/
spring.mvc.view.suffix=.jsp
application.hello=Hello JACK

版本不同的話可能寫法不同，因此我在本文開頭就強調了spring-boot的版本爲1.5.8（老版本寫法不太同樣）。

三、用用程序入口代碼

package com.songhaiqiang.springboot.web.jsp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
public class SpringbootWebJspApplication /*extends SpringBootServletInitializer*/{

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

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

這裏若是繼承了SpringBootServletInitializer並重寫其配置方法。這將能使用Spring框架的servlet 3支持，並容許您在servlet容器啓動時配置應用程序。

四、後臺代碼

package com.songhaiqiang.springboot.web.jsp.web;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

/**
 * Created by songhaiqiang on 2017/10/23.
 */
@Controller
public class LoginController {

	@Value("${application.hello:Hello MYB}")
	private String hello;


	@RequestMapping(value = {"/index"})
	public ModelAndView index(){
		ModelAndView mv = new ModelAndView("welcome");
		mv.addObject("welcome"  , this.hello);

		return mv;
	}
}

這裏不作贅述。

四、頁面代碼

<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
    <title>Title</title>
</head>
<body>


${welcome}
</body>
</html>

作到這一步，已經大功告成。理想下應該能啓動了。

but當我在main方法啓動程序後，訪問頁面的時候卻報404錯誤。更加詭異的是在後臺打上斷點，能夠進去。可是返回頁面的時候報404。以後我用@RestController註釋類的話，是能夠用的，惟一使用@Controller時會返回404。我仔細看下後臺返回路勁是根本沒有問題的。百思不得其解以後，用maven裏面的spring-boot:run啓動。居然能訪問了。本人對此不是很明白。有哪位大神知道能夠告知一下，在下灰常感謝。