淺談HttpClient、okhttp和RestTemplate的區別
一、HttpClient
1、pom依賴
<!--HttpClient-->
<dependency>
<groupId>commons-httpclient</groupId>
<artifactId>commons-httpclient</artifactId>
<version>3.1</version>
</dependency>
2、HttpClient代碼實現
public class HttpClientUtil {
/**
* httpClient的get請求方式
* 使用GetMethod來訪問一個URL對應的網頁實現步驟：
* 1.生成一個HttpClient對象並設置相應的參數；
* 2.生成一個GetMethod對象並設置響應的參數；
* 3.用HttpClient生成的對象來執行GetMethod生成的Get方法；
* 4.處理響應狀態碼；
* 5.若響應正常，處理HTTP響應內容；
* 6.釋放連接。
* @param url
* @param charset
* @return
*/
public static String doGet(String url, String charset) {
//1.生成HttpClient對象並設置參數
HttpClient httpClient = new HttpClient();
//設置Http連接超時為5秒
httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
//2.生成GetMethod對象並設置參數
GetMethod getMethod = new GetMethod(url);
//設置get請求超時為5秒
getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
//設置請求重試處理，用的是默認的重試處理：請求三次
getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
String response = "";
//3.執行HTTP GET 請求
try {
int statusCode = httpClient.executeMethod(getMethod);
//4.判斷訪問的狀態碼
if (statusCode != HttpStatus.SC_OK) {
System.err.println("請求出錯：" + getMethod.getStatusLine());
}
//5.處理HTTP響應內容
//HTTP響應頭部信息，這裡簡單打印
Header[] headers = getMethod.getResponseHeaders();
for(Header h : headers) {
System.out.println(h.getName() + "---------------" + h.getValue());
}
//讀取HTTP響應內容，這裡簡單打印網頁內容
//讀取為字節數組
byte[] responseBody = getMethod.getResponseBody();
response = new String(responseBody, charset);
System.out.println("-----------response:" + response);
//讀取為InputStream，在網頁內容數據量大時候推薦使用
//InputStream response = getMethod.getResponseBodyAsStream();
} catch (HttpException e) {
//發生致命的異常，可能是協議不對或者返回的內容有問題
System.out.println("請檢查輸入的URL!");
e.printStackTrace();
} catch (IOException e) {
//發生網絡異常
System.out.println("發生網絡異常!");
} finally {
//6.釋放連接
getMethod.releaseConnection();
}
return response;
}
/**
* post請求
* @param url
* @param json
* @return
*/
public static String doPost(String url, JSONObject json){
HttpClient httpClient = new HttpClient();
PostMethod postMethod = new PostMethod(url);
postMethod.addRequestHeader("accept", "*/*");
postMethod.addRequestHeader("connection", "Keep-Alive");
//設置json格式傳送
postMethod.addRequestHeader("Content-Type", "application/json;charset=GBK");
//必須設置下面這個Header
postMethod.addRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");
//添加請求參數
postMethod.addParameter("commentId", json.getString("commentId"));
String res = "";
try {
int code = httpClient.executeMethod(postMethod);
if (code == 200){
res = postMethod.getResponseBodyAsString();
System.out.println(res);
}
} catch (IOException e) {
e.printStackTrace();
}
return res;
}
public static void main(String[] args) {
System.out.println(doGet("http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", "GBK"));
System.out.println("-----------分割線------------");
System.out.println("-----------分割線------------");
System.out.println("-----------分割線------------");
JSONObject jsonObject = new JSONObject();
jsonObject.put("commentId", "13026194071");
System.out.println(doPost("http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", jsonObject));
}
}
3、建議
代碼復雜，還得操心資源回收等。代碼很復雜，冗餘代碼多，不建議直接使用。
二、okhttp
1、簡介
OkHttp是一個高效的HTTP客戶端，允許所有同一個主機地址的請求共享同一個socket連接；連接池減少請求延時；透明的GZIP壓縮減少響應數據的大小；緩存響應內容，避免一些完全重復的請求
當網絡出現問題的時候OkHttp依然堅守自己的職責，它會自動恢復一般的連接問題，如果你的服務有多個IP地址，當第一個IP請求失敗時，OkHttp會交替嘗試你配置的其他IP，OkHttp使用現代TLS技術(SNI, ALPN)初始化新的連接，當握手失敗時會回退到TLS 1.0。
2、pom依賴
<dependency>
<groupId>com.squareup.okhttp3</groupId>
<artifactId>okhttp</artifactId>
<version>3.10.0</version>
</dependency>
它的請求/響應 API 使用構造器模式builders來設計，它支持阻塞式的同步請求和帶回調的異步請求。
3、配置文件
@Configuration
public class OkHttpConfig {
@Bean
public OkHttpClient okHttpClient() {
return new OkHttpClient.Builder()
//.sslSocketFactory(sslSocketFactory(), x509TrustManager())
.retryOnConnectionFailure(false)
.connectionPool(pool())
.connectTimeout(30, TimeUnit.SECONDS)
.readTimeout(30, TimeUnit.SECONDS)
.writeTimeout(30,TimeUnit.SECONDS)
.build();
}
@Bean
public X509TrustManager x509TrustManager() {
return new X509TrustManager() {
@Override
public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
}
@Override
public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
}
@Override
public X509Certificate[] getAcceptedIssuers() {
return new X509Certificate[0];
}
};
}
@Bean
public SSLSocketFactory sslSocketFactory() {
try {
//信任任何鏈接
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[]{x509TrustManager()}, new SecureRandom());
return sslContext.getSocketFactory();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (KeyManagementException e) {
e.printStackTrace();
}
return null;
}
/**
* Create a new connection pool with tuning parameters appropriate for a single-user application.
* The tuning parameters in this pool are subject to change in future OkHttp releases. Currently
*/
@Bean
public ConnectionPool pool() {
return new ConnectionPool(200, 5, TimeUnit.MINUTES);
}
}
4、客戶端工具
@Slf4j
public class OkHttpClient {
private static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
private volatile static okhttp3.OkHttpClient client;
private static final int MAX_IDLE_CONNECTION = Integer
.parseInt(ConfigManager.get("httpclient.max_idle_connection"));
private static final long KEEP_ALIVE_DURATION = Long
.parseLong(ConfigManager.get("httpclient.keep_alive_duration"));
private static final long CONNECT_TIMEOUT = Long.parseLong(ConfigManager.get("httpclient.connectTimeout"));
private static final long READ_TIMEOUT = Long.parseLong(ConfigManager.get("httpclient. "));
/**
* 單例模式(雙重檢查模式) 獲取類實例
*
* @return client
*/
private static okhttp3.OkHttpClient getInstance() {
if (client == null) {
synchronized (okhttp3.OkHttpClient.class) {
if (client == null) {
client = new okhttp3.OkHttpClient.Builder()
.connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS)
.readTimeout(READ_TIMEOUT, TimeUnit.SECONDS)
.connectionPool(new ConnectionPool(MAX_IDLE_CONNECTION, KEEP_ALIVE_DURATION,
TimeUnit.MINUTES))
.build();
}
}
}
return client;
}
public static String syncPost(String url, String json) throws IOException {
RequestBody body = RequestBody.create(JSON, json);
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
try {
Response response = OkHttpClient.getInstance().newCall(request).execute();
if (response.isSuccessful()) {
String result = response.body().string();
log.info("syncPost response = {}, responseBody= {}", response, result);
return result;
}
String result = response.body().string();
log.info("syncPost response = {}, responseBody= {}", response, result);
throw new IOException("三方接口返回http狀態碼為" + response.code());
} catch (Exception e) {
log.error("syncPost() url:{} have a ecxeption {}", url, e);
throw new RuntimeException("syncPost() have a ecxeption {}" + e.getMessage());
}
}
public static String syncGet(String url, Map<String, Object> headParamsMap) throws IOException {
Request request;
final Request.Builder builder = new Request.Builder().url(url);
try {
if (!CollectionUtils.isEmpty(headParamsMap)) {
final Iterator<Map.Entry<String, Object>> iterator = headParamsMap.entrySet()
.iterator();
while (iterator.hasNext()) {
final Map.Entry<String, Object> entry = iterator.next();
builder.addHeader(entry.getKey(), (String) entry.getValue());
}
}
request = builder.build();
Response response = OkHttpClient.getInstance().newCall(request).execute();
String result = response.body().string();
log.info("syncGet response = {},responseBody= {}", response, result);
if (!response.isSuccessful()) {
throw new IOException("三方接口返回http狀態碼為" + response.code());
}
return result;
} catch (Exception e) {
log.error("remote interface url:{} have a ecxeption {}", url, e);
throw new RuntimeException("三方接口返回異常");
}
}
}
三、RestTemplate
1、pom依賴
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
2、get請求（不帶參的即把參數取消即可）
// 1-getForObject() User user1 = this.restTemplate.getForObject(uri, User.class); // 2-getForEntity() ResponseEntity<User> responseEntity1 = this.restTemplate.getForEntity(uri, User.class); HttpStatus statusCode = responseEntity1.getStatusCode(); HttpHeaders header = responseEntity1.getHeaders(); User user2 = responseEntity1.getBody(); // 3-exchange() RequestEntity requestEntity = RequestEntity.get(new URI(uri)).build(); ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class); User user3 = responseEntity2.getBody();
方式一：
Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/{1}/{2}"
, Notice.class,1,5);
方式二：
Map<String,String> map = new HashMap();
map.put("start","1");
map.put("page","5");
Notice notice = restTemplate.getForObject("http://fantj.top/notice/list/"
, Notice.class,map);
3、post請求
// 1-postForObject() User user1 = this.restTemplate.postForObject(uri, user, User.class); // 2-postForEntity() ResponseEntity<User> responseEntity1 = this.restTemplate.postForEntity(uri, user, User.class); // 3-exchange() RequestEntity<User> requestEntity = RequestEntity.post(new URI(uri)).body(user); ResponseEntity<User> responseEntity2 = this.restTemplate.exchange(requestEntity, User.class);
方式一：
String url = "http://demo/api/book/";
HttpHeaders headers = new HttpHeaders();
MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
headers.setContentType(type);
String requestJson = "{...}";
HttpEntity<String> entity = new HttpEntity<String>(requestJson,headers);
String result = restTemplate.postForObject(url, entity, String.class);
System.out.println(result);
方式二：
@Test
public void rtPostObject(){
RestTemplate restTemplate = new RestTemplate();
String url = "http://47.xxx.xxx.96/register/checkEmail";
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
MultiValueMap<String, String> map= new LinkedMultiValueMap<>();
map.add("email", "[email protected]");
HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
ResponseEntity<String> response = restTemplate.postForEntity( url, request , String.class );
System.out.println(response.getBody());
}
使用RestTemplate需註意：
使用RestTemplate發送請求，當請求體是String時，應這樣配置：
RestTemplate restTemplate = new RestTemplate(factory);
restTemplate
.getMessageConverters()
.set(1, new StringHttpMessageConverter(StandardCharsets.UTF_8));
如果沒有自定義StringHttpMessageConverter，默認的StringHttpMessageConverter使用的字符集是ISO_8859_1，當請求體包含中文時，會亂碼。
以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。
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