详解SpringBoot通过restTemplate实现消费服务

<?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.chhliu.springboot.restful</groupId> 
  <artifactId>springboot-rest-template</artifactId> 
  <version>0.0.1-SNAPSHOT</version> 
  <packaging>jar</packaging> 
 
  <name>springboot-rest-template</name> 
  <description>Demo project for Spring Boot RestTemplate</description> 
 
  <parent> 
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring-boot-starter-parent</artifactId> 
    <version>1.4.3.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>1.7</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-test</artifactId> 
      <scope>test</scope> 
    </dependency> 
    <!-- 热启动，热部署依赖包，为了调试方便，加入此包 --> 
    <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-devtools</artifactId> 
      <optional>true</optional> 
    </dependency> 
  </dependencies> 
 
  <build> 
    <plugins> 
      <plugin> 
        <groupId>org.springframework.boot</groupId> 
        <artifactId>spring-boot-maven-plugin</artifactId> 
      </plugin> 
    </plugins> 
  </build> 
</project> 

package com.chhliu.springboot.restful.vo; 
 
import java.math.BigDecimal; 
 
public class User { 
 private Long id; 
 
 private String username; 
 
 private String name; 
 
 private Short age; 
 
 private BigDecimal balance; 
 
 // ……省略getter和setter方法 
/** 
 * attention: 
 * Details：TODO 
 * @author chhliu 
 * 创建时间：2017-1-20 下午2:05:45 
 * @return 
 */ 
@Override 
public String toString() { 
  return "User [id=" + id + ", username=" + username + ", name=" + name 
      + ", age=" + age + ", balance=" + balance + "]"; 
} 
} 

package com.chhliu.springboot.restful.controller; 
 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.web.bind.annotation.GetMapping; 
import org.springframework.web.bind.annotation.PathVariable; 
import org.springframework.web.bind.annotation.RestController; 
import org.springframework.web.client.RestTemplate; 
 
import com.chhliu.springboot.restful.vo.User; 
 
@RestController 
public class RestTemplateController { 
  @Autowired 
  private RestTemplate restTemplate; 
 
  @GetMapping("/template/{id}") 
  public User findById(@PathVariable Long id) { 
        // http://localhost:7900/user/是前面服务的对应的url 
        User u = this.restTemplate.getForObject("http://localhost:7900/user/" + id, 
        User.class); 
    System.out.println(u); 
    return u; 
  } 
} 

package com.chhliu.springboot.restful; 
 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 
import org.springframework.boot.web.client.RestTemplateBuilder; 
import org.springframework.context.annotation.Bean; 
import org.springframework.web.client.RestTemplate; 
 
@SpringBootApplication 
public class SpringbootRestTemplateApplication { 
  // 启动的时候要注意，由于我们在controller中注入了RestTemplate，所以启动的时候需要实例化该类的一个实例 
  @Autowired 
  private RestTemplateBuilder builder; 
 
    // 使用RestTemplateBuilder来实例化RestTemplate对象，spring默认已经注入了RestTemplateBuilder实例 
  @Bean 
  public RestTemplate restTemplate() { 
    return builder.build(); 
  } 
 
  public static void main(String[] args) { 
    SpringApplication.run(SpringbootRestTemplateApplication.class, args); 
  } 
} 

User u = this.restTemplate.getForObject("http://localhost:7900/user/" + id, 
        User.class); 

package com.chhliu.springboot.restful.controller; 
 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.beans.factory.annotation.Value; 
import org.springframework.web.bind.annotation.GetMapping; 
import org.springframework.web.bind.annotation.PathVariable; 
import org.springframework.web.bind.annotation.RestController; 
import org.springframework.web.client.RestTemplate; 
 
import com.chhliu.springboot.restful.vo.User; 
 
@RestController 
public class RestTemplateController { 
  @Autowired 
  private RestTemplate restTemplate; 
   
    // Restful服务对应的url地址 
  @Value("${user.userServicePath}") 
  private String userServicePath; 
 
  @GetMapping("/template/{id}") 
  public User findById(@PathVariable Long id) { 
    User u = this.restTemplate.getForObject(this.userServicePath + id, User.class); 
    System.out.println(u); 
    return u; 
  } 
} 

server.port:7902 
user.userServicePath=http://localhost:7900/user/