Spring Boot集成rmi快速入门demo

1.什么是rmi？

RMI（Remote Method Invocation）即远程方法调用，是分布式编程中的一个基本思想。实现远程方法调用的技术有很多，比如CORBA、WebService，这两种都是独立于各个编程语言的。而Java RMI是专为Java环境设计的远程方法调用机制，是一种用于实现远程调用（RPC，Remote Procedure Call）的Java API，能直接传输序列化后的Java对象和分布式垃圾收集。它的实现依赖于JVM，因此它支持从一个JVM到另一个JVM的调用。在Java RMI中，远程服务器实现具体的Java方法并提供接口，客户端本地仅需根据接口类的定义，提供相应的参数即可调用远程方法，其中对象是通过序列化方式进行编码传输的。所以平时说的反序列化漏洞的利用经常是涉及到RMI，就是这个意思。 RMI依赖的通信协议为JRMP（Java Remote Message Protocol，Java远程消息交换协议），该协议是为Java定制的，要求服务端与客户端都必须是Java编写的。

交互过程

rmi_architecture

registry

交互过程可简单概述为：

首先，启动RMI Registry服务，启动时可以指定服务监听的端口，也可以使用默认的端口（1099）；
其次，Server端在本地先实例化一个提供服务的实现类，然后通过RMI提供的Naming/Context/Registry等类的bind或rebind方法将刚才实例化好的实现类注册到RMI Registry上并对外暴露一个名称；
最后，Client端通过本地的接口和一个已知的名称（即RMI Registry暴露出的名称），使用RMI提供的Naming/Context/Registry等类的lookup方法从RMI Service那拿到实现类。这样虽然本地没有这个类的实现类，但所有的方法都在接口里了，便可以实现远程调用对象的方法了；

2.代码工程

实验目标

实验一个简单rmi服务，并且通过客户端调用它

rmi-server

这是一个服务端工程，主要提供rmi service接口

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"><parent><artifactId>rmi</artifactId><groupId>com.et</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>rmi-server</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId></dependency><dependency><groupId>com.et</groupId><artifactId>rmi-common</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>com.h2database</groupId><artifactId>h2</artifactId><version>1.4.200</version></dependency></dependencies>
</project>

config

package com.et.rmi.server.config;import com.et.rmi.server.dao.CustomerRepository;import com.et.rmi.server.model.Customer;
import com.et.rmi.server.service.CustomerServiceImpl;
import om.et.rmi.common.CustomerService;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.context.annotation.Bean;
import org.springframework.remoting.rmi.RmiServiceExporter;
import org.springframework.stereotype.Component;import java.util.logging.Logger;@Component
public class RmiServerApplicationRunner implements ApplicationRunner {private CustomerRepository repository;private CustomerServiceImpl customerService;private final Logger log = Logger.getLogger(this.getClass().getName());public RmiServerApplicationRunner(CustomerServiceImpl customerService) {this.customerService = customerService;}@Overridepublic void run(ApplicationArguments args) throws Exception {Customer customer1 = new Customer("John", "Smith", "123-456-7890");customerService.saveCustomer(customer1);customerService.getCustomers().forEach(System.out::println);}@Beanpublic RmiServiceExporter customerServiceExporter() {RmiServiceExporter customerServiceExporter = new RmiServiceExporter();customerServiceExporter.setRegistryPort(1199);customerServiceExporter.setServiceName("customerService");customerServiceExporter.setServiceInterface(CustomerService.class);customerServiceExporter.setService(customerService);log.info("Started RMI Server");return customerServiceExporter;}
}

service

package com.et.rmi.server.service;import com.et.rmi.server.dao.CustomerRepository;import com.et.rmi.server.mapper.CustomerMapper;
import com.et.rmi.server.model.Customer;
import om.et.rmi.common.CustomerDTO;
import om.et.rmi.common.CustomerService;
import org.springframework.stereotype.Service;import java.util.List;@Service
public class CustomerServiceImpl implements CustomerService {private CustomerRepository repository;public CustomerServiceImpl(CustomerRepository repository) {this.repository = repository;}@Overridepublic CustomerDTO getCustomer(long id) {Customer customer = repository.findById(id).orElseThrow(IllegalArgumentException::new);CustomerMapper mapper = new CustomerMapper();CustomerDTO dto = mapper.mapToDTO(customer);System.out.println(dto);return dto;}public List<Customer> getCustomers() {return (List<Customer>)repository.findAll();}public void saveCustomer(Customer customer) {repository.save(customer);}
}

dao

package com.et.rmi.server.dao;import com.et.rmi.server.model.Customer;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;import java.util.Optional;@Repository
public interface CustomerRepository extends CrudRepository<Customer, Long> {Optional<Customer> findById(long id);
}

mapper

package com.et.rmi.server.mapper;import com.et.rmi.server.model.Customer;import om.et.rmi.common.CustomerDTO;public class CustomerMapper {public CustomerMapper() {}public CustomerDTO mapToDTO(Customer customer){CustomerDTO dto = new CustomerDTO();dto.setFirstName(customer.getFirstName());dto.setLastName(customer.getLastName());dto.setSocialSecurityCode(customer.getSocialSecurityCode());return dto;}
}

model

package com.et.rmi.server.model;import javax.persistence.*;@Entity
@SequenceGenerator(name = "CUST_SEQ", initialValue = 1_000_001)
public class Customer {@Id@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "CUST_SEQ")private long id;private String firstName;private String lastName;private String socialSecurityCode;public Customer() {}public Customer(String firstName, String lastName, String socialSecurityCode) {this.firstName = firstName;this.lastName = lastName;this.socialSecurityCode = socialSecurityCode;}public long getId() {return id;}public String getFirstName() {return firstName;}public void setFirstName(String firstName) {this.firstName = firstName;}public String getLastName() {return lastName;}public void setLastName(String lastName) {this.lastName = lastName;}public String getSocialSecurityCode() {return socialSecurityCode;}public void setSocialSecurityCode(String socialSecurityCode) {this.socialSecurityCode = socialSecurityCode;}@Overridepublic String toString() {return "Customer{" +"id=" + id +", firstName='" + firstName + '\'' +", lastName='" + lastName + '\'' +", socialSecurityCode='" + socialSecurityCode + '\'' +'}';}
}

application.properties

spring.jpa.show-sql=false
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect

rmi-client

这是一个客户端工程，主要调用远程的rmi服务

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"><parent><artifactId>rmi</artifactId><groupId>com.et</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>rmi-cilent</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>com.et</groupId><artifactId>rmi-common</artifactId><version>1.0-SNAPSHOT</version></dependency></dependencies>
</project>

controller

package com.et.rmi.client.controller;import om.et.rmi.common.CustomerDTO;
import om.et.rmi.common.CustomerService;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.remoting.rmi.RmiProxyFactoryBean;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;@Controller
@RequestMapping(value = "customers")
public class CustomerController {private RmiProxyFactoryBean proxyFactoryBean;public CustomerController(RmiProxyFactoryBean proxyFactoryBean) {this.proxyFactoryBean = proxyFactoryBean;}@RequestMapping(value = "{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)public ResponseEntity<CustomerDTO> getCustomer(@PathVariable long id) {CustomerService service = (CustomerService) proxyFactoryBean.getObject();CustomerDTO dto = service.getCustomer(id);return ResponseEntity.ok(dto);}
}

config

package com.et.rmi.client.config;import om.et.rmi.common.CustomerService;
import org.springframework.context.annotation.Bean;
import org.springframework.remoting.rmi.RmiProxyFactoryBean;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;import java.util.logging.Logger;@Component
public class Config {public final Logger log = Logger.getLogger(this.getClass().getName());@Beanpublic RmiProxyFactoryBean proxyFactoryBean() {String remoteHost = System.getProperty("RMI_SERVER_HOST");if(StringUtils.isEmpty(remoteHost)){remoteHost="127.0.0.1";}String rmiHost = String.format("rmi://%s:1199/customerService", remoteHost);log.info("RMI Host name is " + rmiHost);RmiProxyFactoryBean proxy = new RmiProxyFactoryBean();proxy.setServiceInterface(CustomerService.class);proxy.setServiceUrl(rmiHost);proxy.afterPropertiesSet();return proxy;}
}

application.properties

server.port=8081

rmi-common

这是一个公共包，server和client都要引用

package om.et.rmi.common;import java.io.Serializable;public class CustomerDTO implements Serializable {private String firstName;private String lastName;private String socialSecurityCode;public CustomerDTO() {}public String getFirstName() {return firstName;}public void setFirstName(String firstName) {this.firstName = firstName;}public String getLastName() {return lastName;}public void setLastName(String lastName) {this.lastName = lastName;}public String getSocialSecurityCode() {return socialSecurityCode;}public void setSocialSecurityCode(String socialSecurityCode) {this.socialSecurityCode = socialSecurityCode;}@Overridepublic String toString() {final StringBuffer sb = new StringBuffer("CustomerDTO{");sb.append("firstName='").append(firstName).append('\'');sb.append(", lastName='").append(lastName).append('\'');sb.append(", socialSecurityCode='").append(socialSecurityCode).append('\'');sb.append('}');return sb.toString();}
}

package om.et.rmi.common;public interface CustomerService {CustomerDTO getCustomer(long id);
}

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.

3.测试

启动rmi-server服务
启动rmi-client服务
访问http://127.0.0.1:8081/customers/1000001
返回{"firstName":"John","lastName":"Smith","socialSecurityCode":"123-456-7890"}

4.引用

https://www.tutorialspoint.com/java_rmi/java_rmi_introduction.htm
https://docs.oracle.com/javase/8/docs/technotes/guides/rmi/index.html
Spring Boot集成rmi快速入门demo | Harries Blog™