【注】本文译自: https://www.tutorialspoint.com/spring_boot/spring_boot_rest_template.htm
Rest 模板用于创建消费 RESTful Web 服务的应用。你可以使用 exchange() 方法来消费所有 HTTP 方法的 web 服务。下面的代码展示了如何创建 Rest 模板 Bean 来自动绑定 Rest 模板对象:
package com.tutorialspoint.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
public class DemoApplication {
public static void main(String\[\] args) {
SpringApplication.run(DemoApplication.class, args);
}
@Bean
public RestTemplate getRestTemplate() {
return new RestTemplate();
}
GET
使用 RestTemplate - exchange() 方法消费 GET API
假设这个 URL http://localhost:8080/products 返回下面的 JSON ,我们要通过后面的代码使用 Rest 模板来消费这个 API 响应:
[
{
"id": "1",
"name": "Honey"
},
{
"id": "2",
"name": "Almond"
}
]
你要通过以下几点来消费 API:
- 自动绑定 Rest 模板对象
- 使用 HttpHeaders 设置请求头
- 使用 HttpEntity 包装请求对象
- 为 Exchange() 方法提供 URL、HttpMethod 和返回值类型
@RestController
public class ConsumeWebService {
@Autowired
RestTemplate restTemplate;
@RequestMapping(value = "/template/products")
public String getProductList() {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity <String> entity = new HttpEntity<String>(headers);
return restTemplate.exchange("http://localhost:8080/products", HttpMethod.GET, entity, String.class).getBody();
}
}
POST
使用 RestTemplate - exchange() 方法消费 POST API
假设 URL http://localhost:8080/products 返回如下响应,我们要使用 Rest 模板来消费这个 API 响应。
请求体代码如下:
{
"id":"3",
"name":"Ginger"
}
响应体代码如下:
Product is created successfully
你要通过以下几点来消费 API:
- 自动绑定 Rest 模板对象
- 使用 HttpHeaders 设置请求头
- 使用 HttpEntity 包装请求对象,这里我们包装了产品对象发送给请求体
- 为 Exchange() 方法提供 URL、HttpMethod 和返回值类型
@RestController
public class ConsumeWebService {
@Autowired
RestTemplate restTemplate;
@RequestMapping(value = "/template/products", method = RequestMethod.POST)
public String createProducts(@RequestBody Product product) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(product,headers);
return restTemplate.exchange("http://localhost:8080/products", HttpMethod.POST, entity, String.class).getBody();
}
}
PUT
使用 RestTemplate - exchange() 方法消费 PUT API
假设 URL http://localhost:8080/products/3 返回下面的响应,我们要使用 Rest 模板来消费这个 API 响应。
请求体代码如下:
{
"name": "Indian Ginger"
}
响应体代码如下:
Product is updated successfully
你要通过以下几点来消费 API:
- 自动绑定 Rest 模板对象
- 使用 HttpHeaders 设置请求头
- 使用 HttpEntity 包装请求对象,这里我们包装了产品对象发送给请求体
- 为 Exchange() 方法提供 URL、HttpMethod 和返回值类型
@RestController
public class ConsumeWebService {
@Autowired
RestTemplate restTemplate;
@RequestMapping(value = "/template/products/{id}", method = RequestMethod.PUT)
public String updateProduct(@PathVariable("id") String id, @RequestBody Product product) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(product,headers);
return restTemplate.exchange(
"http://localhost:8080/products/"+id, HttpMethod.PUT, entity, String.class).getBody();
}
}
DELETE
使用 RestTemplate - exchange() 方法消费 DELETE API
假设 URL http://localhost:8080/products/3 返回下面的响应,我们要使用 Rest 模板来消费这个 API 响应。
响应体代码如下:
Product is deleted successfully
你要通过以下几点来消费 API:
- 自动绑定 Rest 模板对象
- 使用 HttpHeaders 设置请求头
- 使用 HttpEntity 包装请求对象
- 为 Exchange() 方法提供 URL、HttpMethod 和返回值类型
@RestController
public class ConsumeWebService {
@Autowired
RestTemplate restTemplate;
@RequestMapping(value = "/template/products/{id}", method = RequestMethod.DELETE)
public String deleteProduct(@PathVariable("id") String id) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(headers);
return restTemplate.exchange(
"http://localhost:8080/products/"+id, HttpMethod.DELETE, entity, String.class).getBody();
}
}
完整的 Rest 模板控制器类代码文件如下:
package com.tutorialspoint.demo.controller;
import java.util.Arrays;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
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.tutorialspoint.demo.model.Product;
@RestController
public class ConsumeWebService {
@Autowired
RestTemplate restTemplate;
@RequestMapping(value = "/template/products")
public String getProductList() {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<String>(headers);
return restTemplate.exchange(
"http://localhost:8080/products", HttpMethod.GET, entity, String.class).getBody();
}
@RequestMapping(value = "/template/products", method = RequestMethod.POST)
public String createProducts(@RequestBody Product product) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(product,headers);
return restTemplate.exchange(
"http://localhost:8080/products", HttpMethod.POST, entity, String.class).getBody();
}
@RequestMapping(value = "/template/products/{id}", method = RequestMethod.PUT)
public String updateProduct(@PathVariable("id") String id, @RequestBody Product product) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(product,headers);
return restTemplate.exchange(
"http://localhost:8080/products/"+id, HttpMethod.PUT, entity, String.class).getBody();
}
@RequestMapping(value = "/template/products/{id}", method = RequestMethod.DELETE)
public String deleteProduct(@PathVariable("id") String id) {
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<Product> entity = new HttpEntity<Product>(headers);
return restTemplate.exchange(
"http://localhost:8080/products/"+id, HttpMethod.DELETE, entity, String.class).getBody();
}
}
Spring Boot 应用类 – DemoApplication.java 如下所示:
package com.tutorialspoint.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
Maven build – pom.xml 如下:
<?xml version = "1.0" encoding = "UTF-8"?>
<project xmlns = "[http://maven.apache.org/POM/4.0.0](http://maven.apache.org/POM/4.0.0)"
xmlns:xsi = "[http://www.w3.org/2001/XMLSchema-instance](http://www.w3.org/2001/XMLSchema-instance)"
xsi:schemaLocation = "[http://maven.apache.org/POM/4.0.0](http://maven.apache.org/POM/4.0.0)
[http://maven.apache.org/xsd/maven-4.0.0.xsd](http://maven.apache.org/xsd/maven-4.0.0.xsd)">
<modelVersion>4.0.0</modelVersion>
<groupId>com.tutorialspoint</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
<relativePath>
</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-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>
Gradle Build – build.gradle 如下:
buildscript {
ext {
springBootVersion = '1.5.8.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
dependencies {
compile('org.springframework.boot:spring-boot-starter-web')
testCompile('org.springframework.boot:spring-boot-starter-test')
}
你可以使用 Maven 或 Graven 命令 创建可执行 JAR 文件,并运行 Spring Boot 应用:
Maven 可以使用以下命令:
mvn clean install
在 “BUILD SUCCESS” 之后 ,你可以在 target 目录下找到 JAR 文件:
对于 Gradle,可以使用以下命令:
gradle clean build
在 “BUILD SUCCESSFUL” 之后,你可以在 build/libs 目录下找到 JAR 文件:
使用以下命令运行 JAR 文件:
java –jar <JARFILE>
现在应用已经在 Tomcat 上以 8080 端口上启动了:
在 POSTMAN 应用中输入 URL 可以看到下面的输出:
使用 Rest 模板 GET 产品:http://localhost:8080/template/products
创建产品 POST:http://localhost:8080/template/products
更新产品 PUT:http://localhost:8080/template/products/3
删除产品:http://localhost:8080/template/products/3
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