Java HttpClient-Restful工具各种请求高度封装提炼及总结
极光雨雨 人气:0总思路
总的工具要求底层完全可复用的代码全部提炼,也就是不通类型(GET, POST, DELETE, PUT 等等)请求的决定性公共步骤其实是可以提炼出来的。
即 一个请求,请求头一定会有,请求路径一定会有,发起请求一定会有,返回处理一定会有。
但同时由于请求头内容可能会有不同的要求或者加密方式,所以需要将相关加工过程放到基础工具类之外,保证调用基础工具类时只执行所有请求都需要的的步骤,不带有特殊处理。
这里主要使用的都是 org.apache.http 已包装的 httpClient ,项目中进一步将各种类型的请求做进一步提炼和封装。
从最底层开始说明
RestfulService
基础 RestfulService 工具代码可以参考如下:
个别说明加入到注释中或示例代码结尾
...... import org.apache.http.HttpEntity; import org.apache.http.HttpHeaders; import org.apache.http.NameValuePair; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpPut; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.entity.ContentType; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.CloseableHttpClient; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.URI; import java.nio.charset.StandardCharsets; import java.util.Objects; public class MyRestfulService { private static xxxLogger = new xxxLog(MyRestfulService .class); // 所有请求都由 httpClient.execute() 方式发出 private CloseableHttpClient httpClient; // 由于 httpClient 也存在自定义各种属性,所以这里也作为一个定义的参数 // 通过构造方法传入外侧定义的 CloseableHttpClient public MyRestfulService(CloseableHttpClient client) { this.httpClient = client; } // 一般的GET 请求 public String jsonGet(String url, final NameValuePair[] headerParams) throws IOException, XxxxException { URI uri = URI.create(url); HttpGet get = new HttpGet(uri); this.addHeaders(headerParams, get); CloseableHttpResponse response = httpClient.execute(get); return this.parseResponseData(response, url); } // Get请求 获取文件某字符串开头的 public String fileGetLine(String url, final NameValuePair[] headerParams, String head) throws IOException, XxxxException { URI uri = URI.create(url); HttpGet get = new HttpGet(uri); this.addHeaders(headerParams, get); CloseableHttpResponse response = httpClient.execute(get); BufferedReader br = null; try { br = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8")); String output; while ((output = br.readLine()) != null) { if (output.contains(head) && Objects.equals(output.split("=")[0], head)) { return output; } } return null; } catch (Exception e) { logger.error("Failed to get rest response", e); // 为自定义异常类型 throw new XxxxException(ExceptionType.XXXXXX); } finally { if (br != null) { br.close(); } response.close(); } } // 携带请求体即 Body 的GET 请求 其中 HttpGetWithEntity 需要自定义到文件中 稍后给出示例 public String jsonGetWithBody(String url, final NameValuePair[] headerParams, String requestBody) throws IOException, XxxxException { URI uri = URI.create(url); HttpGetWithEntity get = new HttpGetWithEntity(uri); this.addHeaders(headerParams, get); StringEntity input = new StringEntity(requestBody, ContentType.APPLICATION_JSON); get.setEntity(input); CloseableHttpResponse response = httpClient.execute(get); return this.parseResponseData(response, url); } // 普通的POST 请求 public String jsonPost(String url, final NameValuePair[] headerParams, String requestBody) throws IOException, XxxxException { HttpPost post = new HttpPost(url); this.addHeaders(headerParams, post); if (requestBody != null) { StringEntity input = new StringEntity(requestBody, ContentType.APPLICATION_JSON); post.setEntity(input); } CloseableHttpResponse response = httpClient.execute(post); return this.parseResponseData(response, url); } // 普通 put 请求 public String jsonPut(String url, final NameValuePair[] headerParams, String requestBody) throws IOException, XxxxException { HttpPut put = new HttpPut(url); this.addHeaders(headerParams, put); StringEntity input = new StringEntity(requestBody, ContentType.APPLICATION_JSON); put.setEntity(input); CloseableHttpResponse response = httpClient.execute(put); return this.parseResponseData(response, url); } // 一般的DELETE 请求 public String jsonDelete(String url, final NameValuePair[] headerParams) throws IOException, XxxxException { HttpDelete delete = new HttpDelete(url); this.addHeaders(headerParams, delete); CloseableHttpResponse response = null; response = httpClient.execute(delete); return this.parseResponseData(response, url); } // 携带请求体的DELETE 请求 HttpDeleteWithBody public String jsonDeleteWithBody(String url, final NameValuePair[] headerParams, String requestBody) throws IOException, XxxxException { HttpDeleteWithBody delete = new HttpDeleteWithBody(url); this.addHeaders(headerParams, delete); StringEntity input = new StringEntity(requestBody, ContentType.APPLICATION_JSON); delete.setEntity(input); CloseableHttpResponse response = null; response = httpClient.execute(delete); return this.parseResponseData(response, url); } // 文件类传入 上传 public String uploadFile(String url, final NameValuePair[] headerParams, HttpEntity multipartEntity) throws IOException, XxxxException { HttpPost post = new HttpPost(url); post.setEntity(multipartEntity); post.addHeader(HttpHeaders.CONTENT_TYPE, post.getEntity().getContentType().getValue()); if (headerParams != null) { for (NameValuePair nameValuePair : headerParams) { post.addHeader(nameValuePair.getName(), nameValuePair.getValue()); } } return this.parseResponseData(httpClient.execute(post), url); } // 数据结果转换 private String parseResponseData(CloseableHttpResponse response, String url) throws IOException, XxxxException { BufferedReader br = null; try { // 编码转义结果 br = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), StandardCharsets.UTF_8)); StringBuilder sbuilder = new StringBuilder(); String output; while ((output = br.readLine()) != null) { sbuilder.append(output); } logger.debug("MyRestfulService Request-URL: " + url + "; response: " + response.toString() + "; data:" + sbuilder + "}"); int statusCode = response.getStatusLine().getStatusCode(); // 200 可用已有常量替代 HTTP 本身有提供 if (statusCode != 200) { logger.info("Failed to get restful response, http error code = " + statusCode); } return sbuilder.toString(); } catch (Exception e) { logger.error("Failed to get rest response", e); // 自定义异常 throw new XxxxException(ExceptionType.XXXXXXX); } finally { if (br != null) { br.close(); } response.close(); } } // 公用 添加自定义请求头信息 private void addHeaders(final NameValuePair[] headerParams, HttpRequestBase requestBase) { if (headerParams != null) { for (int i = 0; i < headerParams.length; i++) { NameValuePair nameValuePair = headerParams[i]; requestBase.addHeader(nameValuePair.getName(), nameValuePair.getValue()); } } this.addCommonHeader(requestBase); } // 公用 添加公共请求头或公共操作 private void addCommonHeader(HttpRequestBase method) { // 去除个别属性 if (method.containsHeader("Content-Length")) { method.removeHeaders("Content-Length"); } // 没有则添加 if (!method.containsHeader("Content-Type")) { method.addHeader("Content-Type", "application/json;charset=utf-8"); } // 强制更新或添加 method.setHeader("accept", "application/json,text/plain,text/html"); } // 文件下载 public String downloadFile(String url, OutputStream outputStream,NameValuePair[] headerParams) throws IOException, DXPException { HttpGet httpget = new HttpGet(url); this.addHeaders(headerParams, httpget); CloseableHttpResponse execute = httpClient.execute(httpget); if(null != execute && execute.containsHeader("Content-Disposition")){ HttpEntity entity = execute.getEntity(); if (entity != null ) { entity.writeTo(outputStream); } }else { return this.parseResponseData(execute, url); } return null; } // httpClient 对应的get set 方法 public CloseableHttpClient getHttpClient() { return this.httpClient; } public void setHttpClient(CloseableHttpClient httpClient) { this.httpClient = httpClient; } }
上面
HttpDeleteWithBody 定义:
import java.net.URI; import org.apache.http.client.methods.HttpEntityEnclosingRequestBase; public class HttpDeleteWithBody extends HttpEntityEnclosingRequestBase { public static final String METHOD_NAME = "DELETE"; public HttpDeleteWithBody(final String uri) { super(); setURI(URI.create(uri)); } public HttpDeleteWithBody(final URI uri) { super(); setURI(uri); } public HttpDeleteWithBody() { super(); } public String getMethod() { return METHOD_NAME; } }
上面 HttpGetWithBody:
import org.apache.http.client.methods.HttpEntityEnclosingRequestBase; public class HttpGetWithEntity extends HttpEntityEnclosingRequestBase { private static final String METHOD_NAME = "GET"; public HttpGetWithEntity() { super(); } public HttpGetWithEntity(final URI uri) { super(); setURI(uri); } HttpGetWithEntity(final String uri) { super(); setURI(URI.create(uri)); } @Override public String getMethod() { return METHOD_NAME; } }
具体来源其实就是照抄 源码 httppost POST 的结构
然后换个名字以及属性名即可完成请求体的携带
NameValuePair[]
示例中用到了大量的 NameValuePair[] 其,内部结构类似于 Map 但内部属性为name, value。
实际也可以使用 Map 来替代这种存储结构, NameValuePair 也是 org.apache.http 内部提供的类。
工具类上一层
其他调用者。用于处理特殊的请求头信息,拼接请求参数以及请求路径等内容
并构建使用的 CloseableHttpClient 传入工具类。
示例:
某一 上层 Service 的内容示例:
...... ...... import org.apache.commons.lang.StringUtils; import org.apache.http.HttpHeaders; import org.apache.http.NameValuePair; import org.apache.http.client.config.AuthSchemes; import org.apache.http.client.config.CookieSpecs; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.config.ConnectionConfig; import org.apache.http.config.SocketConfig; import org.apache.http.conn.ssl.NoopHostnameVerifier; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.message.BasicNameValuePair; import org.springframework.stereotype.Service; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.nio.charset.StandardCharsets; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Map; @Service("XXXRestfulService") public class XXXRestfulService implements IXxxRestfulService { private static final XXXLog xxxLog = new XXXLog(XXXRestfulService .class); private static int maxConnPerHost = 20; private static int maxTotalConn = 20; /** * 数据读取超时时间 */ private static int soTimeout = 30000; /** * http连接超时时间 */ private static int connectionTimeout = 10000; /** * 连接管理器超时时间 */ private static int connectionManagerTimeout = 10000; // 基础工具类对象声明 private MyRestfulService restService; private CloseableHttpClient createHttpClient() { CloseableHttpClient httpClient = null; try { @SuppressWarnings("deprecation") ConnectionConfig cConfig = ConnectionConfig.custom().setCharset(StandardCharsets.UTF_8).build(); SocketConfig config = SocketConfig.custom().setSoTimeout(soTimeout).build(); RequestConfig defaultRequestConfig = RequestConfig.custom().setExpectContinueEnabled(true).setCookieSpec(CookieSpecs.DEFAULT) .setTargetPreferredAuthSchemes(Arrays.asList(AuthSchemes.NTLM, AuthSchemes.DIGEST)) .setProxyPreferredAuthSchemes(Arrays.asList(AuthSchemes.BASIC)) .setConnectionRequestTimeout(connectionManagerTimeout).setConnectTimeout(connectionTimeout) .setSocketTimeout(soTimeout).build(); httpClient = HttpClientBuilder.create().setMaxConnPerRoute(maxConnPerHost).setMaxConnTotal(maxTotalConn) .setSSLHostnameVerifier(new NoopHostnameVerifier()) .setDefaultRequestConfig(RequestConfig.copy(defaultRequestConfig).build()) .setDefaultConnectionConfig(cConfig).setDefaultSocketConfig(config).build(); } catch (Exception e) { xxxLog.error("Create Http Client Failed", e); } return httpClient; } // 类初始化时执行的方法 @PostConstruct public void initProperties() { try { CloseableHttpClient client = this.createHttpClient(); this.restService = new MyRestfulService(client); } catch (Exception e) { xxxLog.error("Failed To Init DataFillRestfulService", e); } } // 关闭资源,如果每次都重新请求则也可以放到工具类内每次请求完成都关闭 @PreDestroy // @PreDestroy 实际 Servlet 被销毁前调用的方法 public void destroy() { try { CloseableHttpClient httpclient = restService.getHttpClient(); httpclient.close(); } catch (IOException e) { xxxLog.error("Failed To Destroy HttpClient", e); } } // 对请求头内容的特殊处理 private NameValuePair[] getBaseHeaders(String methodName, String urlStr) { // 对请求头内容的特殊处理 若没有则直接添加到 返回值 NameValuePair[] 数组即可 ............ } // 如果需要URL编码则可以使用该方法 private String encodeHeader(String value) throws UnsupportedEncodingException { if (StringUtils.isEmpty(value)) { return value; } return URLEncoder.encode(value, "UTF-8"); } // 拼接实际请求路径 // XXXXConfig 可以作为一个类专门加载配置文件中的一些有关的地址信息等 public String getRequestUrl(String actionUrl) { return XXXXConfig.getXxxxServer() + actionUrl; } @Override public String get(final String actionUrl, Map<String, String> map) { String requestUrl = getRequestUrl(actionUrl); // 传入实际地址等 调用基础工具类请求 ..... } @Override public String post(final String actionUrl, final String jsonBody) { String requestUrl = getRequestUrl(actionUrl); // 传入实际地址等 调用基础工具类请求 ..... } @Override public String delete(final String actionUrl) { String requestUrl = getRequestUrl(actionUrl); // 传入实际地址等 调用基础工具类请求 ..... } }
可以看的出,上层工具类先声明了 工具类对象 然后在当前类初始化时完成了对当前Service请求自己 httpClient 的相关创建以及配置的赋值,并将该对象 传递给工具类,使得调用工具类时依旧使用的是自己创建的那一个对象。
并通过一般的工具类将需要的配置文件的信息加载后,直接在该类中引用。完成请求信息的拼接。
由于不同的产品间的请求头要求信息可能不同,所以需要自己额外处理请求头相关信息。
这里其实还是在封装部分内容,使得业务请求调用时进一步简化。
一些工具类特殊的传入如下示例:
文件上传方式
public String uploadFile(String url, final NameValuePair[] headerParams, HttpEntity multipartEntity)
中 HttpEntity 中加入文件的方式
MultipartEntityBuilder builder = MultipartEntityBuilder.create(); builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE); builder.setCharset(StandardCharsets.UTF_8); builder.addBinaryBody("file", inputStream, ContentType.DEFAULT_BINARY, fileName); builder.build(); // 最终可以到的 想要的 HttpEntity 携带文件内容
其中 inputStream 为 InputStream 类型的文件输入流, fileName 为 String 文件名;
获取文件流
public String downloadFile(String url, OutputStream outputStream,NameValuePair[] headerParams)
获得请求中的文件流,则需要传入 OutputStream 类型的 输出流对象 outputStream。
再上一层的业务调用
业务层处则通过直接定义指定的方法和入参,在内部直接写入请求映射路径,并要求传入指定参数完成业务封装,类似于:
@Override public XxxxxxxDTO<XXX> getXxxxList(XxxxxListRequest request, String xxx, String xxxx) throws XXXException { String url = "/xxxx/api/xxxx/xxxx/list"; String result = XxxxxRestfulService.post(url, JsonUtil.getJsonStr(request), xxx, xxxx); // 对 result 进行转化 转为自定义类或者Map 等返回 return ......; }
这样在外部调用该业务方法时需要感知的只有入参,其他几乎感知不到,与一般的方法差别几乎没有
以上为个人经验,希望能给大家一个参考,也希望大家多多支持。
加载全部内容