SpringBoot 整合 DWR ,实现 js 直接调用后端 Service

SpringBoot 整合 dwr ,实现 js 直接调用后端 Service

听小伙伴提到一个技术,就自己试了试,下面是一个入门小 demo, 想深入了解的话可以自行研究

DWR 官方主页：http://directwebremoting.org/...
DWR 是一个 Java 库, 它使服务器上的 Java 和浏览器中的 JavaScript 能够尽可能简单地相互交互和调用。

pom.xml

<?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>

    <groupId>com.junbaor</groupId>
    <artifactId>dwr</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>dwr</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        <dependency>
            <groupId>org.directwebremoting</groupId>
            <artifactId>dwr</artifactId>
            <version>3.0.2-RELEASE</version>
        </dependency>
        <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>
        </plugins>
    </build>
    
</project>

DwrApplication.java

package com.junbaor.dwr;

import org.directwebremoting.spring.DwrSpringServlet;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ImportResource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@SpringBootApplication
@ImportResource(locations = "classpath:spring.xml")
public class DwrApplication {

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

    @RequestMapping
    public String index() {
        return "index";
    }

    @Bean
    public ServletRegistrationBean servletRegistrationBean() {
        DwrSpringServlet servlet = new DwrSpringServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(servlet, "/dwr/*");
        registrationBean.addInitParameter("debug", "true");
        return registrationBean;
    }
}

DemoService.java

package com.junbaor.dwr;

import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProxy;
import org.springframework.stereotype.Service;

@Service
@RemoteProxy
public class DemoService {

    // 这里也可以使用 @Autowired 注入依赖的其他服务

    @RemoteMethod
    public String hello() {
        return "hello";
    }

    @RemoteMethod
    public String echo(String string) {
        return string;
    }

}

application.properties

spring.freemarker.template-loader-path=classpath:/templates/
spring.freemarker.cache=false
spring.freemarker.charset=UTF-8
spring.freemarker.check-template-location=true
spring.freemarker.content-type=text/html
spring.freemarker.expose-request-attributes=true
spring.freemarker.expose-session-attributes=true
spring.freemarker.request-context-attribute=request
spring.freemarker.suffix=.ftl

spring.xml

<?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:dwr="http://www.directwebremoting.org/schema/spring-dwr"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.directwebremoting.org/schema/spring-dwr http://www.directwebremoting.org/schema/spring-dwr-3.0.xsd">

    <dwr:annotation-config/>

    <dwr:annotation-scan scanRemoteProxy="false" base-package="com.junbaor.dwr"/>

    <dwr:configuration/>
</beans>

index.ftl

<html>
<head>
    <title></title>
    <script type='text/javascript' src='/dwr/engine.js'></script>
    <script type='text/javascript' src='/dwr/interface/DemoService.js'></script>
</head>
hello
<script>
    DemoService.echo('回声测试', function (str) {
        alert(str);
    });
</script>
</html>

刷新网页, 就会执行后端的 echo 方法, 前端接受响应后会执行回调函数