摘要：最近有一个需求，为客户提供一些RestfulAPI接口，QA使用postman进行测试，但是postman的测试接口与java调用的相似但并不相同，于是想自己写一个程序去测试RestfulAPI接口，由于使用的是HTTPS，所以还要考虑到对于HTTPS的处理。由于我也是首次使用Java调用restful接口，所以还要研究一番，自然也是查阅了一些资料。
分析：这个问题与模块之间的调用不同，比如我有两个模块frontend和backend，frontend提供前台展示，backend提供数据支持。之前使用过Hession去把backend提供的服务注册成远程服务，在frontend端可以通过这种远程服务直接调到backend的接口。但这对于一个公司自己的一个项目耦合性比较高的情况下使用，没有问题。但是如果给客户注册这种远程服务，似乎不太好，耦合性太高。所以就考虑用一下方式进行处理。
基本介绍
Restful接口的调用，前端一般使用ajax调用，后端可以使用的方法比较多，
本次介绍三种：
1.HttpURLConnection实现
2.HttpClient实现
3.Spring的RestTemplate
一、HttpClient
HttpClient大家也许比较熟悉但又比较陌生，熟悉是知道他可以远程调用比如请求一个URL，然后在response里获取到返回状态和返回信息，但是今天讲的稍微复杂一点，因为今天的主题是HTTPS，这个牵涉到证书或用户认证的问题。
确定使用HttpClient之后，查询相关资料，发现HttpClient的新版本与老版本不同，随然兼容老版本，但已经不提倡老版本是使用方式，很多都已经标记为过时的方法或类。今天就分别使用老版本4.2和最新版本4.5.3来写代码。
老版本4.2
需要认证
在准备证书阶段选择的是使用证书认证
package com.darren.test.https.v42;import java.io.File;import java.io.FileInputStream;import java.security.KeyStore;import org.apache.http.conn.ssl.SSLSocketFactory;public class HTTPSCertifiedClient extends HTTPSClient {public HTTPSCertifiedClient() {}@Override public void prepareCertificate() throws Exception {// 获得密匙库 KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());FileInputStream instream = new FileInputStream( new File("C:/Users/zhda6001/Downloads/software/xxx.keystore"));// FileInputStream instream = new FileInputStream(new File("C:/Users/zhda6001/Downloads/xxx.keystore")); // 密匙库的密码 trustStore.load(instream, "password".toCharArray());// 注册密匙库 this.socketFactory = new SSLSocketFactory(trustStore);// 不校验域名 socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);}}跳过认证
在准备证书阶段选择的是跳过认证
package com.darren.test.https.v42;import java.security.cert.CertificateException;import java.security.cert.X509Certificate;import javax.net.ssl.SSLContext;import javax.net.ssl.TrustManager;import javax.net.ssl.X509TrustManager;import org.apache.http.conn.ssl.SSLSocketFactory;public class HTTPSTrustClient extends HTTPSClient {public HTTPSTrustClient() {}@Override public void prepareCertificate() throws Exception {// 跳过证书验证 SSLContext ctx = SSLContext.getInstance("TLS");X509TrustManager tm = new X509TrustManager() {@Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {}@Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {}@Override public X509Certificate[] getAcceptedIssuers() {return null;}};// 设置成已信任的证书 ctx.init(null, new TrustManager[] {tm}, null);// 穿件SSL socket 工厂，并且设置不检查host名称 this.socketFactory = new SSLSocketFactory(ctx, SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);}}总结
现在发现这两个类都继承了同一个类HTTPSClient，并且HTTPSClient继承了DefaultHttpClient类，可以发现，这里使用了模板方法模式。
package com.darren.test.https.v42;import org.apache.http.conn.ClientConnectionManager;import org.apache.http.conn.scheme.Scheme;import org.apache.http.conn.scheme.SchemeRegistry;import org.apache.http.conn.ssl.SSLSocketFactory;import org.apache.http.impl.client.DefaultHttpClient;public abstract class HTTPSClient extends DefaultHttpClient {protected SSLSocketFactory socketFactory;/** * 初始化HTTPSClient * * @return 返回当前实例 * @throws Exception */public HTTPSClient init() throws Exception {this.prepareCertificate();this.regist();return this;}/** * 准备证书验证 * * @throws Exception */public abstract void prepareCertificate() throws Exception;/** * 注册协议和端口, 此方法也可以被子类重写 */protected void regist() {ClientConnectionManager ccm = this.getConnectionManager();SchemeRegistry sr = ccm.getSchemeRegistry();sr.register(new Scheme("https", 443, socketFactory));}}下边是工具类
package com.darren.test.https.v42;import java.util.ArrayList;import java.util.List;import java.util.Map;import java.util.Set;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpRequestBase;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;public class HTTPSClientUtil {private static final String DEFAULT_CHARSET = "UTF-8";public static String doPost(HTTPSClient httpsClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody) throws Exception {return doPost(httpsClient, url, paramHeader, paramBody, DEFAULT_CHARSET);}public static String doPost(HTTPSClient httpsClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody, String charset) throws Exception {String result = null;HttpPost httpPost = new HttpPost(url);setHeader(httpPost, paramHeader);setBody(httpPost, paramBody, charset);HttpResponse response = httpsClient.execute(httpPost);if (response != null) {HttpEntity resEntity = response.getEntity();if (resEntity != null) {result = EntityUtils.toString(resEntity, charset);}}return result;}public static String doGet(HTTPSClient httpsClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody) throws Exception {return doGet(httpsClient, url, paramHeader, paramBody, DEFAULT_CHARSET);}public static String doGet(HTTPSClient httpsClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody, String charset) throws Exception {String result = null;HttpGet httpGet = new HttpGet(url);setHeader(httpGet, paramHeader);HttpResponse response = httpsClient.execute(httpGet);if (response != null) {HttpEntity resEntity = response.getEntity();if (resEntity != null) {result = EntityUtils.toString(resEntity, charset);}}return result;}private static void setHeader(HttpRequestBase request, Map<String, String> paramHeader) {// 设置Header if (paramHeader != null) {Set<String> keySet = paramHeader.keySet();for (String key : keySet) {request.addHeader(key, paramHeader.get(key));}}}private static void setBody(HttpPost httpPost, Map<String, String> paramBody, String charset) throws Exception {// 设置参数 if (paramBody != null) {List<NameValuePair> list = new ArrayList<NameValuePair>();Set<String> keySet = paramBody.keySet();for (String key : keySet) {list.add(new BasicNameValuePair(key, paramBody.get(key)));}if (list.size() > 0) {UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);httpPost.setEntity(entity);}}}}然后是测试类：
package com.darren.test.https.v42;import java.util.HashMap;import java.util.Map;public class HTTPSClientTest {public static void main(String[] args) throws Exception {HTTPSClient httpsClient = null;httpsClient = new HTTPSTrustClient().init();//httpsClient = new HTTPSCertifiedClient().init(); String url = "https://1.2.6.2:8011/xxx/api/getToken";//String url = "https://1.2.6.2:8011/xxx/api/getHealth"; Map<String, String> paramHeader = new HashMap<>();//paramHeader.put("Content-Type", "application/json"); paramHeader.put("Accept", "application/xml");Map<String, String> paramBody = new HashMap<>();paramBody.put("client_id", "[email protected]");paramBody.put("client_secret", "P@ssword_1");String result = HTTPSClientUtil.doPost(httpsClient, url, paramHeader, paramBody);//String result = HTTPSClientUtil.doGet(httpsClient, url, null, null); System.out.println(result);}}返回信息：
<?xml version="1.0" encoding="utf-8"?> <token>jkf8RL0sw+Skkflj8RbKI5hP1bEQK8PrCuTZPpBINqMYKRMxY1kWCjmCfT191Zpp88VV1aGHW8oYNWjEYS0axpLuGAX89ejCoWNbikCc1UvfyesXHLktcJqyUFiVjevhrEQxJPHncLQYWP+Xse5oD9X8vKFKk7InNTMRzQK7YBTZ/e3U7gswM/5cvAHFl6o9rEq9cWPXavZNohyvnXsohSzDo+BXAtXxa1xpEDLy/8h/UaP4n4dlZDJJ3B8t1Xh+CRRIoMOPxf7c5wKhHtOkEOeXW+xoPQKKSx5CKWwJpPuGIIFWF/PaqWg+JUOsVT7QGdPv8PMWJ9DwEwjTdxguDg==</token>
新版本4.5.3
需要认证
package com.darren.test.https.v45;import java.io.File;import java.io.FileInputStream;import java.security.KeyStore;import javax.net.ssl.SSLContext;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.TrustSelfSignedStrategy;import org.apache.http.ssl.SSLContexts;public class HTTPSCertifiedClient extends HTTPSClient {public HTTPSCertifiedClient() {}@Override public void prepareCertificate() throws Exception {// 获得密匙库 KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());FileInputStream instream = new FileInputStream( new File("C:/Users/zhda6001/Downloads/software/xxx.keystore"));// FileInputStream instream = new FileInputStream(new File("C:/Users/zhda6001/Downloads/xxx.keystore")); try {// 密匙库的密码 trustStore.load(instream, "password".toCharArray());}finally {instream.close();}SSLContext sslcontext = SSLContexts.custom().loadTrustMaterial(trustStore, TrustSelfSignedStrategy.INSTANCE) .build();this.connectionSocketFactory = new SSLConnectionSocketFactory(sslcontext);}}跳过认证
package com.darren.test.https.v45;import java.security.cert.CertificateException;import java.security.cert.X509Certificate;import javax.net.ssl.SSLContext;import javax.net.ssl.TrustManager;import javax.net.ssl.X509TrustManager;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;public class HTTPSTrustClient extends HTTPSClient {public HTTPSTrustClient() {}@Override public void prepareCertificate() throws Exception {// 跳过证书验证 SSLContext ctx = SSLContext.getInstance("TLS");X509TrustManager tm = new X509TrustManager() {@Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {}@Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {}@Override public X509Certificate[] getAcceptedIssuers() {return null;}};// 设置成已信任的证书 ctx.init(null, new TrustManager[] {tm}, null);this.connectionSocketFactory = new SSLConnectionSocketFactory(ctx);}}总结
package com.darren.test.https.v45;import org.apache.http.config.Registry;import org.apache.http.config.RegistryBuilder;import org.apache.http.conn.socket.ConnectionSocketFactory;import org.apache.http.conn.socket.PlainConnectionSocketFactory;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClientBuilder;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;public abstract class HTTPSClient extends HttpClientBuilder {private CloseableHttpClient client;protected ConnectionSocketFactory connectionSocketFactory;/** * 初始化HTTPSClient * * @return 返回当前实例 * @throws Exception */public CloseableHttpClient init() throws Exception {this.prepareCertificate();this.regist();return this.client;}/** * 准备证书验证 * * @throws Exception */public abstract void prepareCertificate() throws Exception;/** * 注册协议和端口, 此方法也可以被子类重写 */protected void regist() {// 设置协议http和https对应的处理socket链接工厂的对象 Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create() .register("http", PlainConnectionSocketFactory.INSTANCE) .register("https", this.connectionSocketFactory) .build();PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);HttpClients.custom().setConnectionManager(connManager);// 创建自定义的httpclient对象 this.client = HttpClients.custom().setConnectionManager(connManager).build();// CloseableHttpClient client = HttpClients.createDefault();}}工具类：
package com.darren.test.https.v45;import java.util.ArrayList;import java.util.List;import java.util.Map;import java.util.Set;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpRequestBase;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;public class HTTPSClientUtil {private static final String DEFAULT_CHARSET = "UTF-8";public static String doPost(HttpClient httpClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody) throws Exception {return doPost(httpClient, url, paramHeader, paramBody, DEFAULT_CHARSET);}public static String doPost(HttpClient httpClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody, String charset) throws Exception {String result = null;HttpPost httpPost = new HttpPost(url);setHeader(httpPost, paramHeader);setBody(httpPost, paramBody, charset);HttpResponse response = httpClient.execute(httpPost);if (response != null) {HttpEntity resEntity = response.getEntity();if (resEntity != null) {result = EntityUtils.toString(resEntity, charset);}}return result;}public static String doGet(HttpClient httpClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody) throws Exception {return doGet(httpClient, url, paramHeader, paramBody, DEFAULT_CHARSET);}public static String doGet(HttpClient httpClient, String url, Map<String, String> paramHeader, Map<String, String> paramBody, String charset) throws Exception {String result = null;HttpGet httpGet = new HttpGet(url);setHeader(httpGet, paramHeader);HttpResponse response = httpClient.execute(httpGet);if (response != null) {HttpEntity resEntity = response.getEntity();if (resEntity != null) {result = EntityUtils.toString(resEntity, charset);}}return result;}private static void setHeader(HttpRequestBase request, Map<String, String> paramHeader) {// 设置Header if (paramHeader != null) {Set<String> keySet = paramHeader.keySet();for (String key : keySet) {request.addHeader(key, paramHeader.get(key));}}}private static void setBody(HttpPost httpPost, Map<String, String> paramBody, String charset) throws Exception {// 设置参数 if (paramBody != null) {List<NameValuePair> list = new ArrayList<NameValuePair>();Set<String> keySet = paramBody.keySet();for (String key : keySet) {list.add(new BasicNameValuePair(key, paramBody.get(key)));}if (list.size() > 0) {UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);httpPost.setEntity(entity);}}}}测试类：
package com.darren.test.https.v45;import java.util.HashMap;import java.util.Map;import org.apache.http.client.HttpClient;public class HTTPSClientTest {public static void main(String[] args) throws Exception {HttpClient httpClient = null;//httpClient = new HTTPSTrustClient().init(); httpClient = new HTTPSCertifiedClient().init();String url = "https://1.2.6.2:8011/xxx/api/getToken";//String url = "https://1.2.6.2:8011/xxx/api/getHealth"; Map<String, String> paramHeader = new HashMap<>();paramHeader.put("Accept", "application/xml");Map<String, String> paramBody = new HashMap<>();paramBody.put("client_id", "[email protected]");paramBody.put("client_secret", "P@ssword_1");String result = HTTPSClientUtil.doPost(httpClient, url, paramHeader, paramBody);//String result = HTTPSClientUtil.doGet(httpsClient, url, null, null); System.out.println(result);}}结果：
<?xml version="1.0" encoding="utf-8"?> <token>RxitF9//7NxwXJS2cjIjYhLtvzUNvMZxxEQtGN0u07sC9ysJeIbPqte3hCjULSkoXPEUYGUVeyI9jv7/WikLrzxYKc3OSpaTSM0kCbCKphu0TB2Cn/nfzv9fMLueOWFBdyz+N0sEiI9K+0Gp7920DFEncn17wUJVmC0u2jwvM5FAjQKmilwodXZ6a0Dq+D7dQDJwVcwxBvJ2ilhyIb3pr805Vppmi9atXrVAKO0ODa006wEJFOfcgyG5p70wpJ5rrBL85vfy9WCvkd1R7j6NVjhXgH2gNimHkjEJorMjdXW2gKiUsiWsELi/XPswao7/CTWNwTnctGK8PX2ZUB0ZfA==</token>
二、HttpURLConnection
@Controllerpublic class RestfulAction {@Autowired private UserService userService;// 修改@RequestMapping(value = "put/{param}", method = RequestMethod.PUT) public @ResponseBody String put(@PathVariable String param) {return "put:" + param;}// 新增@RequestMapping(value = "post/{param}", method = RequestMethod.POST) public @ResponseBody String post(@PathVariable String param,String id,String name) {System.out.println("id:"+id);System.out.println("name:"+name);return "post:" + param;}// 删除@RequestMapping(value = "delete/{param}", method = RequestMethod.DELETE) public @ResponseBody String delete(@PathVariable String param) {return "delete:" + param;}// 查找@RequestMapping(value = "get/{param}", method = RequestMethod.GET) public @ResponseBody String get(@PathVariable String param) {return "get:" + param;}// HttpURLConnection 方式调用Restful接口// 调用接口@RequestMapping(value = "dealCon/{param}") public @ResponseBody String dealCon(@PathVariable String param) {try {String url = "http://localhost:8080/tao-manager-web/";url+=(param+"/xxx");URL restServiceURL = new URL(url);HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL .openConnection();//param 输入小写，转换成 GET POST DELETE PUT httpConnection.setRequestMethod(param.toUpperCase());// httpConnection.setRequestProperty("Accept", "application/json");if("post".equals(param)){//打开输出开关httpConnection.setDoOutput(true);// httpConnection.setDoInput(true);//传递参数String input = "&id="+ URLEncoder.encode("abc", "UTF-8");input+="&name="+ URLEncoder.encode("啊啊啊", "UTF-8");OutputStream outputStream = httpConnection.getOutputStream();outputStream.write(input.getBytes());outputStream.flush();}if (httpConnection.getResponseCode() != 200) {throw new RuntimeException( "HTTP GET Request Failed with Error code : " + httpConnection.getResponseCode());}BufferedReader responseBuffer = new BufferedReader( new InputStreamReader((httpConnection.getInputStream())));String output;System.out.println("Output from Server: /n");while ((output = responseBuffer.readLine()) != null) {System.out.println(output);}httpConnection.disconnect();}catch (MalformedURLException e) {e.printStackTrace();}catch (IOException e) {e.printStackTrace();}return "success";}}三、Spring的RestTemplate
springmvc.xml增加
<!-- 配置RestTemplate --> <!--Http client Factory --> <bean id="httpClientFactory" > <property name="connectTimeout" value="10000" /> <property name="readTimeout" value="10000" /> </bean> <!--RestTemplate --> <bean id="restTemplate"> <constructor-arg ref="httpClientFactory" /> </bean>
controller
@Controllerpublic class RestTemplateAction {@Autowired private RestTemplate template;@RequestMapping("RestTem") public @ResponseBody User RestTem(String method) {User user = null;//查找if ("get".equals(method)) {user = template.getForObject( "http://localhost:8080/tao-manager-web/get/{id}", User.class, "呜呜呜呜");//getForEntity与getForObject的区别是可以获取返回值和状态、头等信息ResponseEntity<User> re = template. getForEntity("http://localhost:8080/tao-manager-web/get/{id}", User.class, "呜呜呜呜");System.out.println(re.getStatusCode());System.out.println(re.getBody().getUsername());//新增} else if ("post".equals(method)) {HttpHeaders headers = new HttpHeaders();headers.add("X-Auth-Token", UUID.randomUUID().toString());MultiValueMap<String, String> postParameters = new LinkedMultiValueMap<String, String>();postParameters.add("id", "啊啊啊");postParameters.add("name", "部版本");HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>( postParameters, headers);user = template.postForObject( "http://localhost:8080/tao-manager-web/post/aaa", requestEntity, User.class);//删除} else if ("delete".equals(method)) {template.delete("http://localhost:8080/tao-manager-web/delete/{id}","aaa");//修改} else if ("put".equals(method)) {template.put("http://localhost:8080/tao-manager-web/put/{id}",null,"bbb");}return user;}}以上就是本文关于浅谈java调用Restful API接口的方式的全部内容，希望对大家有所帮助。感兴趣的朋友可以继续参阅本站其他Java相关专题，如有不足之处，欢迎留言指出。感谢朋友们对本站的支持！