0、準備工作

本文中介紹的工程依賴Spring Boot（五）json格式的快取，我們姑且簡稱它為工程A，所以在啟動本文的專案之前，我們應該先啟動工程A。在啟動工程A成功後，開啟postman，新增一個user，如下圖：

另外我將本文介紹的工程成為工程B，專案A和B的關係就是B會通過http請求拿到A的響應，響應的請求體是一段代表User的json程式碼。

1、建立工程

<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.github.ralgond</groupId>
  <artifactId>boot-resttmp</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.3.0.RELEASE</version>
	</parent>

	<properties>
		<start-class>
	com.github.ralgond.bootresttmp.BootResttmpMainApp</start-class>
	</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-json</artifactId>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.0</version>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>
 

2、工程佈局如下圖

3、編輯application.yml

server:
  port: 7777

4、編輯User類

package com.github.ralgond.bootresttmp.entity;

public class User {
	private Integer id;
    private String name;
    
	public User() {
	}
	public User(Integer id, String name) {
		this.id = id;
		this.name = name;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + "]";
	}
}
 

5、編輯配置類RestTemplateConfig

package com.github.ralgond.bootresttmp;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestTemplateConfig {
	@Bean
	RestTemplate restTemplate() {
		return new RestTemplate();
	}
}
 

6、編輯主啟動類

package com.github.ralgond.bootresttmp;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
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.RestController;
import org.springframework.web.client.RestTemplate;

import com.github.ralgond.bootresttmp.entity.User;


@SpringBootApplication
@RestController
public class BootResttmpMainApp {
	
	@Autowired
	RestTemplate restTemplate;
	
	@RequestMapping(method=RequestMethod.GET, value="/user/{id}")
	public User getUser(@PathVariable("id") int id) {
		User user = restTemplate.getForObject("http://localhost:8888/user/"+id, User.class);
		System.out.println("====>get from remote: "+user);
		return user;
	}
	
	public static void main(String args[]) {
		SpringApplication.run(BootResttmpMainApp.class, args);
	}
}

7、啟動主啟動類