SpringCloud——接口互相调用(RestTemplate+Ribbon)-蒲公英云

我之前写过两个接口服务user和student，现在将它完善一下

user，创建一个接口 localhost:12003/getUserList 返回一个json数据，用来做测试

UserApi.java

package com.springcloud.demo.api;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.springcloud.demo.domain.BaseJSON;
import com.springcloud.demo.domain.po.UserPO;
import com.springcloud.demo.server.UserService;
@RestController
public class UserApi {
    @Autowired
    public UserService userService;
    @RequestMapping(value="/test",method=RequestMethod.GET)
    public String test() {
        return "Hello World";
    }
    @RequestMapping(value="/getUserList",method=RequestMethod.GET)
    public BaseJSON getUserList() {
        BaseJSON json = new BaseJSON();
        List<UserPO> list = userService.getUserList();
        if(list.size()<0||list==null) {
            json.setCode(11);
            json.setMessage("失败");
        }else {
            json.setResult(list);
        }
        return json;
    }
}

Service层实现

package com.springcloud.demo.server.imp;
import java.util.ArrayList;
import java.util.List;
import org.springframework.stereotype.Service;
import com.springcloud.demo.domain.po.UserPO;
import com.springcloud.demo.server.UserService;
@Service
public class UserServiceImp implements UserService{
    @Override
    public List<UserPO> getUserList() {
        List<UserPO> list = new ArrayList<>();
        UserPO user = new UserPO();
        user.setId(1);
        user.setUsername("lg");
        user.setPassword("123456");
        list.add(user);
        user.setId(2);
        user.setUsername("lxy");
        user.setPassword("123456");
        list.add(user);
        return list;
    }
}

Student 调用 user的restFul接口，获取数据，然后将数据重新封装

70 1

首先我们需要注入RestTemplate，这里我们图方便加载BootMain中了，使用@LoadBalanced注解标明

package com.springcloud.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.client.RestTemplate;
import springfox.documentation.annotations.ApiIgnore;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Controller
@SpringBootApplication
@ApiIgnore
@EnableScheduling 
@EnableDiscoveryClient
@EnableFeignClients
@EnableSwagger2
@EnableHystrixDashboard
public class BootMain {
    public static void main(String[] args) {
        SpringApplication.run(BootMain.class, args);
    }
    @RequestMapping("/help")
    public String help() {
        return "redirect:swagger-ui.html";
    }
    /**
    重点看这里
    */
    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

service调用实现

【注】：

1、RestTemplate 访问的URL不能携带ip和端口号，不然会报错,改成你所调用的服务在注册中心注册的名字

报错 
No instances available for 192.168.xx.xx
No instances available for [IP]

2、使用Entity接收RestTemplate获取到的值

@Autowired 
private RestTemplate rt;
//ResponseEntity<BaseJSON> re = rt.getForEntity(url, BaseJSON.class);
HttpEntity<BaseJSON> re = rt.getForEntity(url, BaseJSON.class);
BaseJSON json = re.getBody();

获取到的json就是我门的目标json对象（BaseJSON自己封装的），里面拥有从user获取到的全部数据
3、在获取对象时候，我们得到的Object无法直接转为目标对象StudentPO，我们可以先将其转为json字符串，然后再转为我们的目标对象，需要在pom.xml中加入jar包，具体java<——>操作可见：json数据对象操作

<dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
        </dependency>
package com.springcloud.demo.service.imp;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import com.springcloud.demo.domain.BaseJSON;
import com.springcloud.demo.domain.po.StudentPO;
import com.springcloud.demo.domain.po.UserPO;
import com.springcloud.demo.service.StudentService;
import net.sf.json.JSONObject;
@Service
public class StudentServiceImp implements StudentService{
    @Autowired 
    private RestTemplate rt;
    @Override
    public List<StudentPO> getStudentList() {
        //使用RestTemplate
        String url = "http://user/getUserList";
        /**
         * String url = "http://192.168.99.115:12001/user/getUserList";
          * 报错：No instances available for [IP]
         */
        //ResponseEntity<BaseJSON> re = rt.getForEntity(url, BaseJSON.class);
        HttpEntity<BaseJSON> re = rt.getForEntity(url, BaseJSON.class);
        BaseJSON json = re.getBody();
        List<UserPO> userList = new ArrayList();
        List<StudentPO> studentList = new ArrayList();
        if(json.getCode()==0) {
            userList = (List<UserPO>) json.getResult();
            for(Object obj:userList) {
                JSONObject jsonObject = JSONObject.fromObject(obj);
                UserPO user = (UserPO)jsonObject.toBean(jsonObject,UserPO.class);
                StudentPO student = new StudentPO();
                student.setId(user.getId());
                student.setName(user.getUsername());
                student.setPassword(user.getUsername());
                student.setGrade(1);
                studentList.add(student);
            }
        }else {
            studentList = null;
        }
        return studentList;
    }
}