【前後端分離】的開發方式是目前WEB開發中的一個大的趨勢,随着各種前後端架構的出現,加上REST程式設計規範慢慢深入人心,前端後端之間通過更加輕量級、簡潔高效的JSON作為資料傳輸格式,使得一切變得開朗起來,前後端分工更加明晰,前端被賦予了更多的功能,進而能分擔原來由後端完成的工作,開發人員的學習成本明顯下降。
通過VUE+SPringMVC的組合來嘗試實作前後端分離的開發模式,下面給出具體的過程。
1.搭建前端
VUE是優秀的前端架構,搭建基于VUE的前端工程需要安裝Node.js,并通過NPM包管理工具和VUE-cli腳手架工具來輔助建構前端工程,如下:
# 全局安裝 vue-cli
$ npm install --global vue-cli
# 建立一個基于 webpack 模闆的新項目
$ vue init webpack my-project
# 安裝依賴,走你
$ cd my-project
$ npm install
$ npm run dev
這樣我們就建構了一個前段項目的架子my-project,目錄結構如下圖:
然後再浏覽器中可以看到如下的頁面:
前端搞定,輪到後端
2.搭建後端
後端是用maven來建構的web項目,在eclipse(使用2017年6月釋出的Oxygen)目錄結構如下:
其中配置檔案主要為pom.xml、web.xml、applicationContext.xml、SpringMVC-servlet.xml,具體内容如下。
pom.xml是maven的配置檔案,如下
<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>my-first-maven-project</groupId>
<artifactId>hello-maven</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>hello-maven Maven Webapp</name>
<url>http://maven.apache.org</url>
<!-- <properties>
<spring-version></spring-version>
</properties> -->
<!-- dependencyManagement配置有問題 -->
<!-- <dependencyManagement>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
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>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.7.9.1</version>
</dependency>
</dependencies>
</dependencyManagement> -->
<!-- dependencies配置沒有問題 -->
<dependencies>
<!-- Junit單元測試依賴包 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- SpringMVC依賴包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.10.RELEASE</version>
</dependency>
<!-- JSON處理依賴包 -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.7.9.1</version>
</dependency>
</dependencies>
<build>
<finalName>hello-maven</finalName>
<plugins>
<plugin>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>9.2.2.v20140723</version>
</plugin>
</plugins>
</build>
</project>
web.xml為整個web應用的配置檔案
<!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>My first SpringMVC APP</display-name>
<!-- Spring應用上下文,了解階層化的ApplicationContext -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/configurations/spring/applicationContext*.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 配置允許跨域通路
<filter-mapping>
<filter-name>CorsFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping> -->
<!-- SpringMVC配置 -->
<servlet>
<servlet-name>SpringMVC-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/configurations/spring/SpringMVC-servlet.xml</param-value>
<!-- 預設是/WEB-INF/[servlet名字]-servlet.xml -->
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>SpringMVC-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
applicationContext.xml為Spring配置檔案
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 使用注解的依賴注入(DI)管理 -->
<context:annotation-config/>
<!-- 告訴Spring不用管理@controller标記的類 -->
<context:component-scan base-package="com.muxinxin.springmvcdemo">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
</beans>
SpringMVC-servlet.xml為SpringMVC配置檔案
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
<!-- SpringMVC配置 -->
<!-- 激活@required 等注釋 -->
<context:annotation-config/>
<!-- 設定使用注解的類所在的jar包 ,DispatcherServlet上下文,隻搜尋@Controller标記的類-->
<context:component-scan base-package="com.muxinxin.springmvcdemo">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- 啟動基于注解的HandlerMapping,可以将請求參數綁定到控制器參數 -->
<mvc:annotation-driven/>
<!-- 靜态資源配置,css, js, imgs -->
<mvc:resources location="/resources/" mapping="/resources/**"/>
<!-- 配置ViewResolver
可以配置多個ViewResolver
使用order屬性排序
InternalResourceViewResolver放在最後
-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsps/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
作為測試的controller為HelloMvcController.java
package com.muxinxin.springmvcdemo.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.muxinxin.springmvcdemo.model.Person;
@Controller
@RequestMapping("/hello")
public class HelloMvcController {
@RequestMapping("/home")
public String homeHandler(){
return "home";
}
@RequestMapping("/test")
public String testHandler(){
return "test";
}
/**
* 使用JSON作為響應内容
*/
@CrossOrigin(origins="*",maxAge=)
@RequestMapping(value="/getperson/{personID}",method=RequestMethod.GET)
public @ResponseBody Person getPerson(@PathVariable int personID) {
Person p = new Person();
p.setName("Eric");
p.setSex("male");
p.setId(personID);
return p;
}
}
使用jetty的maven插件作為web容器,配置在pom.xml中,在項目所在目錄輸入下面指令啟動後端項目
3.結果
對前端APP.vue做如下修改,資料異步請求使用的是Vue官方推薦的axios插件。
修改前
<template>
<div id="app">
<img src="./assets/logo.png">
<router-view></router-view>
</div>
</template>
<script>
export default {
name: 'app'
}
</script>
修改後
<template>
<div id="app">
<h1>服務端資料為:{{serverData}}</h1>
<img src="./assets/logo.png" @click="getData()">
<router-view></router-view>
</div>
</template>
<script>
export default {
name: 'app',
data () {
return {
serverData: 'data from fake server'
}
},
mounted: function () {
this.getData()
},
methods: {
getData () {
console.log('-------getData')
var that = this
//192.168.1.101為後端IP位址 this.$http.get('http://192.168.1.101:8080/hello/getperson/33333')
.then(function (response) {
console.log(response)
console.log(this)
that.serverData = response.data
})
.catch(function (error) {
console.log(error)
})
}
}
}
</script>
準備就緒後檢視前端頁面,變為
資料成功拿到!!!!!!!
4.遇到的坑(經驗)
-
NRM
在使用npm安裝依賴包的時候,可以用nrm這個插件來切換npm鏡像,非常友善,推薦使用。
-
跨域
一般跨域的解決方式為:粗粒度和細粒度
粗粒度(全局):配置全局允許跨域
細粒度:在具體API上通過注解配置,如SpringMVC中的@CrossOrigin
5.總結
至此,使用VUE+SpringMVC的方式來實作前後端分離開發就被簡單完成了。