玩转Spring Boot之RestTemplate的使用

闫同学

发布于 2022-10-31 15:05:39

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发布于 2022-10-31 15:05:39

文章被收录于专栏：扯编程的淡

1 RestTemplate简介

在java代码里想要进行restful web client服务，一般使用Apache的HttpClient。不过此种方法使用起来太过繁琐。Spring Boot提供了一种简单便捷的内置模板类来进行操作，这就是RestTemplate。

2 RestTemplate基本使用

2.1 依赖：

Spring Boot的web starter已经内置了RestTemplate的Bean，我们主需要将它引入到我们的Spring Context中，再进行下简单的配置就可以直接使用了。

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.76</version>
</dependency>

2.2 Web服务端代码：

这部分代码作为Http请求的服务端：

/**
 * @desc: HTTP服务端
 * @author: YanMingXin
 * @create: 2022/1/15-18:08
 **/
@RestController
public class RestControllerDemo {

    /**
     * 普通Get
     *
     * @param name
     * @return
     */
    @GetMapping("/get")
    private String getMethod(@RequestParam("name") String name) {
        System.out.println("getMethod : name=" + name);
        return name;
    }

    /**
     * Restful Get
     *
     * @param name
     * @return
     */
    @GetMapping("/getName/{name}")
    private String getRestName(@PathVariable("name") String name) {
        System.out.println("getRestName : name=" + name);
        return name;
    }

    /**
     * post
     *
     * @param name
     * @return
     */
    @PostMapping("/post")
    private String postMethod(@RequestParam("name") String name) {
        System.out.println("postMethod : name=" + name);
        return name;
    }

    /**
     * post json
     *
     * @param stu
     * @return
     */
    @PostMapping("/postBody")
    public String postBodyMethod(@RequestBody String stu) {
        Student student = JSONObject.parseObject(stu, Student.class);
        System.out.println("postBodyMethod : student=" + student);
        return student.toString();
    }

    /**
     * delete
     *
     * @param name
     * @return
     */
    @DeleteMapping("/delete")
    public String deleteMethod(@RequestParam("name") String name) {
        System.out.println("deleteMethod : name=" + name);
        return name;
    }

    /**
     * put
     *
     * @param name
     * @return
     */
    @PutMapping("/put")
    public String putMethod(@RequestParam("name") String name) {
        System.out.println("putMethod : name=" + name);
        return name;
    }
}

2.3 RestTemplate代码：

配置：

/**
 * @desc: RestTemplate配置
 * @author: YanMingXin
 * @create: 2022/1/15-17:34
 **/
@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
        return new RestTemplate(factory);
    }

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setReadTimeout(5000);
        factory.setConnectTimeout(15000);
        return factory;
    }
}

使用测试：

@SpringBootTest
class DemoApplicationTests {

    @Resource
    private RestTemplate restTemplate;

    @Test
    void getTest() {
        String str = restTemplate.getForObject("http://localhost:8888/get?name=zs", String.class);
        System.out.println(str);
    }

    @Test
    void getRestTest() {
        String name = "ls";
        String str = restTemplate.getForObject("http://localhost:8888/getName/" + name, String.class);
        System.out.println(str);
    }

    @Test
    void postTest() {
        LinkedMultiValueMap<String, String> map = new LinkedMultiValueMap<>();
        map.set("name", "zs");
        String str = restTemplate.postForObject("http://localhost:8888/post", map, String.class);
        System.out.println(str);
    }

    @Test
    void postBodyTest() {
        HttpHeaders headers = new HttpHeaders();
        MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
        headers.setContentType(type);
        headers.add("Accept", MediaType.APPLICATION_JSON.toString());
        HashMap<String, Object> map = new HashMap<>();
        map.put("name", "zs");
        map.put("age", 23);
        String stu = JSON.toJSONString(map);
        HttpEntity<String> formEntity = new HttpEntity<String>(stu, headers);
        String str = restTemplate.postForObject("http://localhost:8888/postBody", formEntity, String.class);
        System.out.println(str);
    }

    @Test
    void putTest() {
        restTemplate.put("http://localhost:8888/put?name=zs", null);
    }

    @Test
    void deleteTest() {
        restTemplate.delete("http://localhost:8888/delete?name=zs");
    }
}