接口调用神器RestTemplate（四）

/**
 * body中json格式的数据，返回值非泛型
 *
 * @param bookDto
 * @return
 */
@PostMapping("/test/form4")
@ResponseBody
public BookDto form4(@RequestBody BookDto bookDto) {
    return bookDto;
}

@Test
public void test15() {
    RestTemplate restTemplate = new RestTemplate();
    String url = "http://localhost:8080/chat16/test/form4";
    BookDto body = new BookDto(1, "SpringMVC系列");
    BookDto result = restTemplate.postForObject(url, body, BookDto.class);
    System.out.println(result);
}

BookDto{id=1, name='SpringMVC系列'}

/**
 * body中json格式的数据，返回值为泛型
 *
 * @param bookDtoList
 * @return
 */
@PostMapping("/test/form5")
@ResponseBody
public List<BookDto> form5(@RequestBody List<BookDto> bookDtoList) {
    return bookDtoList;
}

@Test
public void test16() {
    RestTemplate restTemplate = new RestTemplate();
    String url = "http://localhost:8080/chat16/test/form5";
    //①：请求体，发送的时候会被转换为json格式数据
    List<BookDto> body = Arrays.asList(
            new BookDto(1, "SpringMVC系列"),
            new BookDto(2, "MySQL系列"));
    //②：头
    HttpHeaders headers = new HttpHeaders();
    headers.add("header1", "v1");
    headers.add("header2", "v2");
    //③：请求实体
    RequestEntity requestEntity = new RequestEntity(body, headers, HttpMethod.POST, URI.create(url));
    //④：发送请求(请求实体，返回值需要转换的类型)
    ResponseEntity<List<BookDto>> responseEntity = restTemplate.exchange(
            requestEntity,
            new ParameterizedTypeReference<List<BookDto>>() {
            });
    //⑤：获取结果
    List<BookDto> result = responseEntity.getBody();
    System.out.println(result);
}

[BookDto{id=1, name='SpringMVC系列'}, BookDto{id=2, name='MySQL系列'}]

@Test
public void test17() {
    RestTemplate restTemplate = new RestTemplate();
    String url = "http://localhost:8080/chat16/test/form5";
    //①：请求体为一个json格式的字符串
    String body = "[{\"id\":1,\"name\":\"SpringMVC系列\"},{\"id\":2,\"name\":\"MySQL系列\"}]";
    /**
     * ②：若请求体为json字符串的时候，需要在头中设置Content-Type=application/json；
     * 若body是普通的java类的时候，无需指定这个，RestTemplate默认自动配上Content-Type=application/json
     */
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_JSON);
    //③：请求实体（body，头、请求方式，uri）
    RequestEntity requestEntity = new RequestEntity(body, headers, HttpMethod.POST, URI.create(url));
    //④：发送请求(请求实体，返回值需要转换的类型)
    ResponseEntity<List<BookDto>> responseEntity = restTemplate.exchange(
            requestEntity,
            new ParameterizedTypeReference<List<BookDto>>() {
            });
    //⑤：获取结果
    List<BookDto> result = responseEntity.getBody();
    System.out.println(result);
}

[BookDto{id=1, name='SpringMVC系列'}, BookDto{id=2, name='MySQL系列'}]

public void delete(String url, Object... uriVariables);
public void delete(String url, Map<String, ?> uriVariables);
public void delete(URI url);

public Set<HttpMethod> optionsForAllow(String url, Object... uriVariables);
public Set<HttpMethod> optionsForAllow(String url, Map<String, ?> uriVariables);
public Set<HttpMethod> optionsForAllow(URI url);

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.7</version>
</dependency>

public HttpClient httpClient() {
    HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
    try {
        //设置信任ssl访问
        SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, (arg0, arg1) -> true).build();
        httpClientBuilder.setSSLContext(sslContext);
        HostnameVerifier hostnameVerifier = NoopHostnameVerifier.INSTANCE;
        SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(sslContext, hostnameVerifier);
        Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
                // 注册http和https请求
                .register("http", PlainConnectionSocketFactory.getSocketFactory())
                .register("https", sslConnectionSocketFactory).build();
        //使用Httpclient连接池的方式配置(推荐)，同时支持netty，okHttp以及其他http框架
        PoolingHttpClientConnectionManager poolingHttpClientConnectionManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
        // 最大连接数
        poolingHttpClientConnectionManager.setMaxTotal(1000);
        // 同路由并发数
        poolingHttpClientConnectionManager.setDefaultMaxPerRoute(100);
        //配置连接池
        httpClientBuilder.setConnectionManager(poolingHttpClientConnectionManager);
        // 重试次数
        httpClientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler(0, true));
        //设置默认请求头
        List<Header> headers = new ArrayList<>();
        httpClientBuilder.setDefaultHeaders(headers);
        return httpClientBuilder.build();
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}
public ClientHttpRequestFactory clientHttpRequestFactory() {
    HttpComponentsClientHttpRequestFactory clientHttpRequestFactory = new HttpComponentsClientHttpRequestFactory(httpClient());
    // 连接超时(毫秒)，这里设置10秒
    clientHttpRequestFactory.setConnectTimeout(10 * 1000);
    // 数据读取超时时间(毫秒)，这里设置60秒
    clientHttpRequestFactory.setReadTimeout(60 * 1000);
    // 从连接池获取请求连接的超时时间(毫秒)，不宜过长，必须设置，比如连接不够用时，时间过长将是灾难性的
    clientHttpRequestFactory.setConnectionRequestTimeout(10 * 1000);
    return clientHttpRequestFactory;
}
public RestTemplate restTemplate(){
    //创建RestTemplate的时候，指定ClientHttpRequestFactory
    return new RestTemplate(this.clientHttpRequestFactory());
}
@Test
public void test18() {
    RestTemplate restTemplate = this.restTemplate();
    String url = "http://localhost:8080/chat16/test/get";
    //getForObject方法，获取响应体，将其转换为第二个参数指定的类型
    BookDto bookDto = restTemplate.getForObject(url, BookDto.class);
    System.out.println(bookDto);
}

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>4.3.1</version>
</dependency>

new RestTemplate(new OkHttp3ClientHttpRequestFactory());