Java-Class-C：org.springframework.web.client.RestTemplate.java

ylbtech-Java-Class-C：org.springframework.web.client.RestTemplate.java

1、

java.lang.Object继承
- org.springframework.http.client.support.HttpAccessor
- - org.springframework.http.client.support.InterceptingHttpAccessor
  - - org.springframework.web.client.RestTemplate

所有已实现的接口：
RestOperations
```
公共类RestTemplate 
扩展InterceptingHttpAccessor 
实现RestOperations
```
同步客户端执行HTTP请求，在底层HTTP客户端库（如JDK HttpURLConnection，Apache HttpComponents 等）上公开简单的模板方法API 。
RestTemplate通过HTTP方法提供常见方案的模板，此外还支持不太常见的案例的通用方法exchange和execute方法。

注意：从5.0开始，非阻塞，无效，为同步和异步以及流方案org.springframework.web.reactive.client.WebClient提供了RestTemplate有效支持的现代替代方案。该RestTemplate 会在未来的版本中被淘汰，并没有重大的新功能的加入前进。有关更多详细信息和示例代码，请参阅Spring Framework参考文档的WebClient部分。

2、

1.1、

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;

import java.nio.charset.StandardCharsets;

1.2、restTemplate.getForEntity()

/**
     * 接口调用凭证
     * 获取小程序全局唯一后台接口调用凭据（access_token）
     * https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/access-token/auth.getAccessToken.html
     * @param appID 必填，小程序唯一凭证，即 AppID，可在「微信公众平台 - 设置 - 开发设置」页中获得。（需要已经成为开发者，且帐号没有异常状态）
     * @param secret 必填，小程序唯一凭证密钥，即 AppSecret，获取方式同 appid
     * @param restTemplate 必填
     * @return
     */
    public static String getAccessToken(String appID, String secret, RestTemplate restTemplate) {

        String url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential";
        String path = String.format("%s&appid=%s&secret=%s", url, appID, secret);
        ResponseEntity<String> entity = restTemplate.getForEntity(path, String.class);
        return entity.getBody();
    }

1.3、restTemplate.postForEntity()

 /**
     * 组合模板并添加至帐号下的个人模板库
     * @param access_token 必填，接口调用凭证
     * @param id  必填，模板标题id，可通过接口获取，也可登录小程序后台查看获取
     * @param keyword_id_list  必填，开发者自行组合好的模板关键词列表，关键词顺序可以自由搭配（例如[3,5,4]或[4,5,3]），最多支持10个关键词组合
     * @param restTemplate 必填
     * @return
     */
    public static String addTemplate(String access_token, String id, List<Integer> keyword_id_list, RestTemplate restTemplate) {

        restTemplate.getMessageConverters().set(1, new StringHttpMessageConverter(StandardCharsets.UTF_8)); // 防止中文乱码
        String url = "https://api.weixin.qq.com/cgi-bin/wxopen/template/add?access_token="+access_token;
        //请求头
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        //请求体
        Map<String, Object> requestParam = new HashMap<>();
        requestParam.put("id", id);
        requestParam.put("keyword_id_list",keyword_id_list);

        //封装成一个请求对象
        HttpEntity entity = new HttpEntity(requestParam, headers);
        //发送数据方法
        ResponseEntity<String> forEntity = restTemplate.postForEntity(url, entity, String.class);

        //得到返回的数据body
        return forEntity.getBody();
    }

2、

3.返回顶部

4.返回顶部

1、

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.web.client;

import java.io.IOException;
import java.lang.reflect.Type;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.http.ResponseEntity.BodyBuilder;
import org.springframework.http.client.ClientHttpRequest;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.support.InterceptingHttpAccessor;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.GenericHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.ResourceHttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.cbor.MappingJackson2CborHttpMessageConverter;
import org.springframework.http.converter.feed.AtomFeedHttpMessageConverter;
import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
import org.springframework.http.converter.json.GsonHttpMessageConverter;
import org.springframework.http.converter.json.JsonbHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.smile.MappingJackson2SmileHttpMessageConverter;
import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
import org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter;
import org.springframework.http.converter.xml.SourceHttpMessageConverter;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.web.util.AbstractUriTemplateHandler;
import org.springframework.web.util.DefaultUriBuilderFactory;
import org.springframework.web.util.UriTemplateHandler;
import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode;

public class RestTemplate extends InterceptingHttpAccessor implements RestOperations {
    private static boolean romePresent;
    private static final boolean jaxb2Present;
    private static final boolean jackson2Present;
    private static final boolean jackson2XmlPresent;
    private static final boolean jackson2SmilePresent;
    private static final boolean jackson2CborPresent;
    private static final boolean gsonPresent;
    private static final boolean jsonbPresent;
    private final List<HttpMessageConverter<?>> messageConverters;
    private ResponseErrorHandler errorHandler;
    private UriTemplateHandler uriTemplateHandler;
    private final ResponseExtractor<HttpHeaders> headersExtractor;

    public RestTemplate() {
        this.messageConverters = new ArrayList();
        this.errorHandler = new DefaultResponseErrorHandler();
        this.headersExtractor = new RestTemplate.HeadersExtractor();
        this.messageConverters.add(new ByteArrayHttpMessageConverter());
        this.messageConverters.add(new StringHttpMessageConverter());
        this.messageConverters.add(new ResourceHttpMessageConverter(false));

        try {
            this.messageConverters.add(new SourceHttpMessageConverter());
        } catch (Error var2) {
            ;
        }

        this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());
        if (romePresent) {
            this.messageConverters.add(new AtomFeedHttpMessageConverter());
            this.messageConverters.add(new RssChannelHttpMessageConverter());
        }

        if (jackson2XmlPresent) {
            this.messageConverters.add(new MappingJackson2XmlHttpMessageConverter());
        } else if (jaxb2Present) {
            this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
        }

        if (jackson2Present) {
            this.messageConverters.add(new MappingJackson2HttpMessageConverter());
        } else if (gsonPresent) {
            this.messageConverters.add(new GsonHttpMessageConverter());
        } else if (jsonbPresent) {
            this.messageConverters.add(new JsonbHttpMessageConverter());
        }

        if (jackson2SmilePresent) {
            this.messageConverters.add(new MappingJackson2SmileHttpMessageConverter());
        }

        if (jackson2CborPresent) {
            this.messageConverters.add(new MappingJackson2CborHttpMessageConverter());
        }

        this.uriTemplateHandler = initUriTemplateHandler();
    }

    public RestTemplate(ClientHttpRequestFactory requestFactory) {
        this();
        this.setRequestFactory(requestFactory);
    }

    public RestTemplate(List<HttpMessageConverter<?>> messageConverters) {
        this.messageConverters = new ArrayList();
        this.errorHandler = new DefaultResponseErrorHandler();
        this.headersExtractor = new RestTemplate.HeadersExtractor();
        Assert.notEmpty(messageConverters, "At least one HttpMessageConverter required");
        this.messageConverters.addAll(messageConverters);
        this.uriTemplateHandler = initUriTemplateHandler();
    }

    private static DefaultUriBuilderFactory initUriTemplateHandler() {
        DefaultUriBuilderFactory uriFactory = new DefaultUriBuilderFactory();
        uriFactory.setEncodingMode(EncodingMode.URI_COMPONENT);
        return uriFactory;
    }

    public void setMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
        Assert.notEmpty(messageConverters, "At least one HttpMessageConverter required");
        if (this.messageConverters != messageConverters) {
            this.messageConverters.clear();
            this.messageConverters.addAll(messageConverters);
        }

    }

    public List<HttpMessageConverter<?>> getMessageConverters() {
        return this.messageConverters;
    }

    public void setErrorHandler(ResponseErrorHandler errorHandler) {
        Assert.notNull(errorHandler, "ResponseErrorHandler must not be null");
        this.errorHandler = errorHandler;
    }

    public ResponseErrorHandler getErrorHandler() {
        return this.errorHandler;
    }

    public void setDefaultUriVariables(Map<String, ?> uriVars) {
        if (this.uriTemplateHandler instanceof DefaultUriBuilderFactory) {
            ((DefaultUriBuilderFactory)this.uriTemplateHandler).setDefaultUriVariables(uriVars);
        } else {
            if (!(this.uriTemplateHandler instanceof AbstractUriTemplateHandler)) {
                throw new IllegalArgumentException("This property is not supported with the configured UriTemplateHandler.");
            }

            ((AbstractUriTemplateHandler)this.uriTemplateHandler).setDefaultUriVariables(uriVars);
        }

    }

    public void setUriTemplateHandler(UriTemplateHandler handler) {
        Assert.notNull(handler, "UriTemplateHandler must not be null");
        this.uriTemplateHandler = handler;
    }

    public UriTemplateHandler getUriTemplateHandler() {
        return this.uriTemplateHandler;
    }

    @Nullable
    public <T> T getForObject(String url, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.GET, requestCallback, responseExtractor, (Object[])uriVariables);
    }

    @Nullable
    public <T> T getForObject(String url, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.GET, requestCallback, responseExtractor, (Map)uriVariables);
    }

    @Nullable
    public <T> T getForObject(URI url, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.GET, requestCallback, responseExtractor);
    }

    public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.GET, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.GET, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> getForEntity(URI url, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.GET, requestCallback, responseExtractor));
    }

    public HttpHeaders headForHeaders(String url, Object... uriVariables) throws RestClientException {
        return (HttpHeaders)nonNull(this.execute(url, HttpMethod.HEAD, (RequestCallback)null, this.headersExtractor(), (Object[])uriVariables));
    }

    public HttpHeaders headForHeaders(String url, Map<String, ?> uriVariables) throws RestClientException {
        return (HttpHeaders)nonNull(this.execute(url, HttpMethod.HEAD, (RequestCallback)null, this.headersExtractor(), (Map)uriVariables));
    }

    public HttpHeaders headForHeaders(URI url) throws RestClientException {
        return (HttpHeaders)nonNull(this.execute(url, HttpMethod.HEAD, (RequestCallback)null, this.headersExtractor()));
    }

    @Nullable
    public URI postForLocation(String url, @Nullable Object request, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.POST, requestCallback, this.headersExtractor(), uriVariables);
        return headers != null ? headers.getLocation() : null;
    }

    @Nullable
    public URI postForLocation(String url, @Nullable Object request, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.POST, requestCallback, this.headersExtractor(), uriVariables);
        return headers != null ? headers.getLocation() : null;
    }

    @Nullable
    public URI postForLocation(URI url, @Nullable Object request) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.POST, requestCallback, this.headersExtractor());
        return headers != null ? headers.getLocation() : null;
    }

    @Nullable
    public <T> T postForObject(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.POST, requestCallback, responseExtractor, (Object[])uriVariables);
    }

    @Nullable
    public <T> T postForObject(String url, @Nullable Object request, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.POST, requestCallback, responseExtractor, (Map)uriVariables);
    }

    @Nullable
    public <T> T postForObject(URI url, @Nullable Object request, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters());
        return this.execute(url, HttpMethod.POST, requestCallback, responseExtractor);
    }

    public <T> ResponseEntity<T> postForEntity(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> postForEntity(String url, @Nullable Object request, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> postForEntity(URI url, @Nullable Object request, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, HttpMethod.POST, requestCallback, responseExtractor));
    }

    public void put(String url, @Nullable Object request, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        this.execute(url, HttpMethod.PUT, requestCallback, (ResponseExtractor)null, (Object[])uriVariables);
    }

    public void put(String url, @Nullable Object request, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        this.execute(url, HttpMethod.PUT, requestCallback, (ResponseExtractor)null, (Map)uriVariables);
    }

    public void put(URI url, @Nullable Object request) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request);
        this.execute(url, HttpMethod.PUT, requestCallback, (ResponseExtractor)null);
    }

    @Nullable
    public <T> T patchForObject(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.PATCH, requestCallback, responseExtractor, (Object[])uriVariables);
    }

    @Nullable
    public <T> T patchForObject(String url, @Nullable Object request, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.PATCH, requestCallback, responseExtractor, (Map)uriVariables);
    }

    @Nullable
    public <T> T patchForObject(URI url, @Nullable Object request, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(request, responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters());
        return this.execute(url, HttpMethod.PATCH, requestCallback, responseExtractor);
    }

    public void delete(String url, Object... uriVariables) throws RestClientException {
        this.execute(url, HttpMethod.DELETE, (RequestCallback)null, (ResponseExtractor)null, (Object[])uriVariables);
    }

    public void delete(String url, Map<String, ?> uriVariables) throws RestClientException {
        this.execute(url, HttpMethod.DELETE, (RequestCallback)null, (ResponseExtractor)null, (Map)uriVariables);
    }

    public void delete(URI url) throws RestClientException {
        this.execute(url, HttpMethod.DELETE, (RequestCallback)null, (ResponseExtractor)null);
    }

    public Set<HttpMethod> optionsForAllow(String url, Object... uriVariables) throws RestClientException {
        ResponseExtractor<HttpHeaders> headersExtractor = this.headersExtractor();
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.OPTIONS, (RequestCallback)null, headersExtractor, (Object[])uriVariables);
        return headers != null ? headers.getAllow() : Collections.emptySet();
    }

    public Set<HttpMethod> optionsForAllow(String url, Map<String, ?> uriVariables) throws RestClientException {
        ResponseExtractor<HttpHeaders> headersExtractor = this.headersExtractor();
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.OPTIONS, (RequestCallback)null, headersExtractor, (Map)uriVariables);
        return headers != null ? headers.getAllow() : Collections.emptySet();
    }

    public Set<HttpMethod> optionsForAllow(URI url) throws RestClientException {
        ResponseExtractor<HttpHeaders> headersExtractor = this.headersExtractor();
        HttpHeaders headers = (HttpHeaders)this.execute(url, HttpMethod.OPTIONS, (RequestCallback)null, headersExtractor);
        return headers != null ? headers.getAllow() : Collections.emptySet();
    }

    public <T> ResponseEntity<T> exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, Class<T> responseType, Object... uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> exchange(URI url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor));
    }

    public <T> ResponseEntity<T> exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, ParameterizedTypeReference<T> responseType, Object... uriVariables) throws RestClientException {
        Type type = responseType.getType();
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, type);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(type);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> exchange(String url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, ParameterizedTypeReference<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
        Type type = responseType.getType();
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, type);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(type);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor, uriVariables));
    }

    public <T> ResponseEntity<T> exchange(URI url, HttpMethod method, @Nullable HttpEntity<?> requestEntity, ParameterizedTypeReference<T> responseType) throws RestClientException {
        Type type = responseType.getType();
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, type);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(type);
        return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor));
    }

    public <T> ResponseEntity<T> exchange(RequestEntity<?> requestEntity, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, responseType);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(responseType);
        return (ResponseEntity)nonNull(this.doExecute(requestEntity.getUrl(), requestEntity.getMethod(), requestCallback, responseExtractor));
    }

    public <T> ResponseEntity<T> exchange(RequestEntity<?> requestEntity, ParameterizedTypeReference<T> responseType) throws RestClientException {
        Type type = responseType.getType();
        RequestCallback requestCallback = this.httpEntityCallback(requestEntity, type);
        ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(type);
        return (ResponseEntity)nonNull(this.doExecute(requestEntity.getUrl(), requestEntity.getMethod(), requestCallback, responseExtractor));
    }

    @Nullable
    public <T> T execute(String url, HttpMethod method, @Nullable RequestCallback requestCallback, @Nullable ResponseExtractor<T> responseExtractor, Object... uriVariables) throws RestClientException {
        URI expanded = this.getUriTemplateHandler().expand(url, uriVariables);
        return this.doExecute(expanded, method, requestCallback, responseExtractor);
    }

    @Nullable
    public <T> T execute(String url, HttpMethod method, @Nullable RequestCallback requestCallback, @Nullable ResponseExtractor<T> responseExtractor, Map<String, ?> uriVariables) throws RestClientException {
        URI expanded = this.getUriTemplateHandler().expand(url, uriVariables);
        return this.doExecute(expanded, method, requestCallback, responseExtractor);
    }

    @Nullable
    public <T> T execute(URI url, HttpMethod method, @Nullable RequestCallback requestCallback, @Nullable ResponseExtractor<T> responseExtractor) throws RestClientException {
        return this.doExecute(url, method, requestCallback, responseExtractor);
    }

    @Nullable
    protected <T> T doExecute(URI url, @Nullable HttpMethod method, @Nullable RequestCallback requestCallback, @Nullable ResponseExtractor<T> responseExtractor) throws RestClientException {
        Assert.notNull(url, "URI is required");
        Assert.notNull(method, "HttpMethod is required");
        ClientHttpResponse response = null;

        Object var14;
        try {
            ClientHttpRequest request = this.createRequest(url, method);
            if (requestCallback != null) {
                requestCallback.doWithRequest(request);
            }

            response = request.execute();
            this.handleResponse(url, method, response);
            var14 = responseExtractor != null ? responseExtractor.extractData(response) : null;
        } catch (IOException var12) {
            String resource = url.toString();
            String query = url.getRawQuery();
            resource = query != null ? resource.substring(0, resource.indexOf(63)) : resource;
            throw new ResourceAccessException("I/O error on " + method.name() + " request for "" + resource + "": " + var12.getMessage(), var12);
        } finally {
            if (response != null) {
                response.close();
            }

        }

        return var14;
    }

    protected void handleResponse(URI url, HttpMethod method, ClientHttpResponse response) throws IOException {
        ResponseErrorHandler errorHandler = this.getErrorHandler();
        boolean hasError = errorHandler.hasError(response);
        if (this.logger.isDebugEnabled()) {
            try {
                int code = response.getRawStatusCode();
                HttpStatus status = HttpStatus.resolve(code);
                this.logger.debug("Response " + (status != null ? status : code));
            } catch (IOException var8) {
                ;
            }
        }

        if (hasError) {
            errorHandler.handleError(url, method, response);
        }

    }

    public <T> RequestCallback acceptHeaderRequestCallback(Class<T> responseType) {
        return new RestTemplate.AcceptHeaderRequestCallback(responseType);
    }

    public <T> RequestCallback httpEntityCallback(@Nullable Object requestBody) {
        return new RestTemplate.HttpEntityRequestCallback(requestBody);
    }

    public <T> RequestCallback httpEntityCallback(@Nullable Object requestBody, Type responseType) {
        return new RestTemplate.HttpEntityRequestCallback(requestBody, responseType);
    }

    public <T> ResponseExtractor<ResponseEntity<T>> responseEntityExtractor(Type responseType) {
        return new RestTemplate.ResponseEntityResponseExtractor(responseType);
    }

    protected ResponseExtractor<HttpHeaders> headersExtractor() {
        return this.headersExtractor;
    }

    private static <T> T nonNull(@Nullable T result) {
        Assert.state(result != null, "No result");
        return result;
    }

    static {
        ClassLoader classLoader = RestTemplate.class.getClassLoader();
        romePresent = ClassUtils.isPresent("com.rometools.rome.feed.WireFeed", classLoader);
        jaxb2Present = ClassUtils.isPresent("javax.xml.bind.Binder", classLoader);
        jackson2Present = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) && ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
        jackson2XmlPresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.xml.XmlMapper", classLoader);
        jackson2SmilePresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.smile.SmileFactory", classLoader);
        jackson2CborPresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.cbor.CBORFactory", classLoader);
        gsonPresent = ClassUtils.isPresent("com.google.gson.Gson", classLoader);
        jsonbPresent = ClassUtils.isPresent("javax.json.bind.Jsonb", classLoader);
    }

    private static class HeadersExtractor implements ResponseExtractor<HttpHeaders> {
        private HeadersExtractor() {
        }

        public HttpHeaders extractData(ClientHttpResponse response) {
            return response.getHeaders();
        }
    }

    private class ResponseEntityResponseExtractor<T> implements ResponseExtractor<ResponseEntity<T>> {
        @Nullable
        private final HttpMessageConverterExtractor<T> delegate;

        public ResponseEntityResponseExtractor(@Nullable Type responseType) {
            if (responseType != null && Void.class != responseType) {
                this.delegate = new HttpMessageConverterExtractor(responseType, RestTemplate.this.getMessageConverters(), RestTemplate.this.logger);
            } else {
                this.delegate = null;
            }

        }

        public ResponseEntity<T> extractData(ClientHttpResponse response) throws IOException {
            if (this.delegate != null) {
                T body = this.delegate.extractData(response);
                return ((BodyBuilder)ResponseEntity.status(response.getRawStatusCode()).headers(response.getHeaders())).body(body);
            } else {
                return ((BodyBuilder)ResponseEntity.status(response.getRawStatusCode()).headers(response.getHeaders())).build();
            }
        }
    }

    private class HttpEntityRequestCallback extends RestTemplate.AcceptHeaderRequestCallback {
        private final HttpEntity<?> requestEntity;

        public HttpEntityRequestCallback(@Nullable Object requestBody) {
            this(requestBody, (Type)null);
        }

        public HttpEntityRequestCallback(@Nullable Object requestBody, @Nullable Type responseType) {
            super(responseType);
            if (requestBody instanceof HttpEntity) {
                this.requestEntity = (HttpEntity)requestBody;
            } else if (requestBody != null) {
                this.requestEntity = new HttpEntity(requestBody);
            } else {
                this.requestEntity = HttpEntity.EMPTY;
            }

        }

        public void doWithRequest(ClientHttpRequest httpRequest) throws IOException {
            super.doWithRequest(httpRequest);
            Object requestBody = this.requestEntity.getBody();
            if (requestBody == null) {
                HttpHeaders httpHeaders = httpRequest.getHeaders();
                HttpHeaders requestHeaders = this.requestEntity.getHeaders();
                if (!requestHeaders.isEmpty()) {
                    requestHeaders.forEach((key, values) -> {
                        httpHeaders.put(key, new LinkedList(values));
                    });
                }

                if (httpHeaders.getContentLength() < 0L) {
                    httpHeaders.setContentLength(0L);
                }

            } else {
                Class<?> requestBodyClass = requestBody.getClass();
                Type requestBodyType = this.requestEntity instanceof RequestEntity ? ((RequestEntity)this.requestEntity).getType() : requestBodyClass;
                HttpHeaders httpHeadersx = httpRequest.getHeaders();
                HttpHeaders requestHeadersx = this.requestEntity.getHeaders();
                MediaType requestContentType = requestHeadersx.getContentType();
                Iterator var8 = RestTemplate.this.getMessageConverters().iterator();

                while(var8.hasNext()) {
                    HttpMessageConverter<?> messageConverter = (HttpMessageConverter)var8.next();
                    if (messageConverter instanceof GenericHttpMessageConverter) {
                        GenericHttpMessageConverter<Object> genericConverter = (GenericHttpMessageConverter)messageConverter;
                        if (genericConverter.canWrite((Type)requestBodyType, requestBodyClass, requestContentType)) {
                            if (!requestHeadersx.isEmpty()) {
                                requestHeadersx.forEach((key, values) -> {
                                    httpHeadersx.put(key, new LinkedList(values));
                                });
                            }

                            this.logBody(requestBody, requestContentType, genericConverter);
                            genericConverter.write(requestBody, (Type)requestBodyType, requestContentType, httpRequest);
                            return;
                        }
                    } else if (messageConverter.canWrite(requestBodyClass, requestContentType)) {
                        if (!requestHeadersx.isEmpty()) {
                            requestHeadersx.forEach((key, values) -> {
                                httpHeadersx.put(key, new LinkedList(values));
                            });
                        }

                        this.logBody(requestBody, requestContentType, messageConverter);
                        messageConverter.write(requestBody, requestContentType, httpRequest);
                        return;
                    }
                }

                String message = "No HttpMessageConverter for " + requestBodyClass.getName();
                if (requestContentType != null) {
                    message = message + " and content type "" + requestContentType + """;
                }

                throw new RestClientException(message);
            }
        }

        private void logBody(Object body, @Nullable MediaType mediaType, HttpMessageConverter<?> converter) {
            if (RestTemplate.this.logger.isDebugEnabled()) {
                if (mediaType != null) {
                    RestTemplate.this.logger.debug("Writing [" + body + "] as "" + mediaType + """);
                } else {
                    RestTemplate.this.logger.debug("Writing [" + body + "] with " + converter.getClass().getName());
                }
            }

        }
    }

    private class AcceptHeaderRequestCallback implements RequestCallback {
        @Nullable
        private final Type responseType;

        public AcceptHeaderRequestCallback(@Nullable Type responseType) {
            this.responseType = responseType;
        }

        public void doWithRequest(ClientHttpRequest request) throws IOException {
            if (this.responseType != null) {
                List<MediaType> allSupportedMediaTypes = (List)RestTemplate.this.getMessageConverters().stream().filter((converter) -> {
                    return this.canReadResponse(this.responseType, converter);
                }).flatMap(this::getSupportedMediaTypes).distinct().sorted(MediaType.SPECIFICITY_COMPARATOR).collect(Collectors.toList());
                if (RestTemplate.this.logger.isDebugEnabled()) {
                    RestTemplate.this.logger.debug("Accept=" + allSupportedMediaTypes);
                }

                request.getHeaders().setAccept(allSupportedMediaTypes);
            }

        }

        private boolean canReadResponse(Type responseType, HttpMessageConverter<?> converter) {
            Class<?> responseClass = responseType instanceof Class ? (Class)responseType : null;
            if (responseClass != null) {
                return converter.canRead(responseClass, (MediaType)null);
            } else if (converter instanceof GenericHttpMessageConverter) {
                GenericHttpMessageConverter<?> genericConverter = (GenericHttpMessageConverter)converter;
                return genericConverter.canRead(responseType, (Class)null, (MediaType)null);
            } else {
                return false;
            }
        }

        private Stream<MediaType> getSupportedMediaTypes(HttpMessageConverter<?> messageConverter) {
            return messageConverter.getSupportedMediaTypes().stream().map((mediaType) -> {
                return mediaType.getCharset() != null ? new MediaType(mediaType.getType(), mediaType.getSubtype()) : mediaType;
            });
        }
    }
}

2、

5.返回顶部

1、

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/client/RestTemplate.html

2、

6.返回顶部

作者：ylbtech
出处：http://ylbtech.cnblogs.com/
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。

Java-Class-C：org.springframework.web.client.RestTemplate.java

类RestTemplate