目錄
使用
HttpClient和OkHttp一般用於調用其它服務，一般服務暴露出來的接口都爲http，http常用請求類型就爲GET、PUT、POST和DELETE，因此主要介紹這些請求類型的調用
HttpClient使用介紹
使用HttpClient發送請求主要分爲以下幾步驟：
- 創建 CloseableHttpClient對象或CloseableHttpAsyncClient對象，前者同步，後者爲異步
- 創建Http請求對象
- 調用execute方法執行請求，如果是異步請求在執行之前需調用start方法
創建連接：
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
該連接爲同步連接
GET請求：
@Test
public void testGet() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
HttpGet httpGet = new HttpGet(url);
CloseableHttpResponse response = httpClient.execute(httpGet);
System.out.println(EntityUtils.toString(response.getEntity()));
}
使用HttpGet表示該連接爲GET請求，HttpClient調用execute方法發送GET請求
PUT請求：
@Test
public void testPut() throws IOException {
String api = "/api/user";
String url = String.format("%s%s", BASE_URL, api);
HttpPut httpPut = new HttpPut(url);
UserVO userVO = UserVO.builder().name("h2t").id(16L).build();
httpPut.setHeader("Content-Type", "application/json;charset=utf8");
httpPut.setEntity(new StringEntity(JSONObject.toJSONString(userVO), "UTF-8"));
CloseableHttpResponse response = httpClient.execute(httpPut);
System.out.println(EntityUtils.toString(response.getEntity()));
}
POST請求：
添加對象
@Test
public void testPost() throws IOException {
String api = "/api/user";
String url = String.format("%s%s", BASE_URL, api);
HttpPost httpPost = new HttpPost(url);
UserVO userVO = UserVO.builder().name("h2t2").build();
httpPost.setHeader("Content-Type", "application/json;charset=utf8");
httpPost.setEntity(new StringEntity(JSONObject.toJSONString(userVO), "UTF-8"));
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));
}
該請求是一個創建對象的請求，需要傳入一個json字符串
上傳文件
@Test
public void testUpload1() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
HttpPost httpPost = new HttpPost(url);
File file = new File("C:/Users/hetiantian/Desktop/學習/docker_practice.pdf");
FileBody fileBody = new FileBody(file);
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
builder.addPart("file", fileBody); //addPart上傳文件
HttpEntity entity = builder.build();
httpPost.setEntity(entity);
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));
}
通過addPart上傳文件
DELETE請求：
@Test
public void testDelete() throws IOException {
String api = "/api/user/12";
String url = String.format("%s%s", BASE_URL, api);
HttpDelete httpDelete = new HttpDelete(url);
CloseableHttpResponse response = httpClient.execute(httpDelete);
System.out.println(EntityUtils.toString(response.getEntity()));
}
請求的取消：
@Test
public void testCancel() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
HttpGet httpGet = new HttpGet(url);
httpGet.setConfig(requestConfig); //設置超時時間
//測試連接的取消
long begin = System.currentTimeMillis();
CloseableHttpResponse response = httpClient.execute(httpGet);
while (true) {
if (System.currentTimeMillis() - begin > 1000) {
httpGet.abort();
System.out.println("task canceled");
break;
}
}
System.out.println(EntityUtils.toString(response.getEntity()));
}
調用abort方法取消請求 執行結果：
task canceled
cost 8098 msc
Disconnected from the target VM, address: '127.0.0.1:60549', transport: 'socket'
java.net.SocketException: socket closed...【省略】
OkHttp使用
使用OkHttp發送請求主要分爲以下幾步驟：
- 創建OkHttpClient對象
- 創建Request對象
- 將Request 對象封裝爲Call
- 通過Call 來執行同步或異步請求，調用execute方法同步執行，調用enqueue方法異步執行
創建連接：
private OkHttpClient client = new OkHttpClient();
GET請求：
@Test
public void testGet() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
Request request = new Request.Builder()
.url(url)
.get()
.build();
final Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}
PUT請求：
@Test
public void testPut() throws IOException {
String api = "/api/user";
String url = String.format("%s%s", BASE_URL, api);
//請求參數
UserVO userVO = UserVO.builder().name("h2t").id(11L).build();
RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"),
JSONObject.toJSONString(userVO));
Request request = new Request.Builder()
.url(url)
.put(requestBody)
.build();
final Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}
POST請求：
添加對象
@Test
public void testPost() throws IOException {
String api = "/api/user";
String url = String.format("%s%s", BASE_URL, api);
//請求參數
JSONObject json = new JSONObject();
json.put("name", "hetiantian");
RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), String.valueOf(json));
Request request = new Request.Builder()
.url(url)
.post(requestBody) //post請求
.build();
final Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}
上傳文件
@Test
public void testUpload() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
RequestBody requestBody = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("file", "docker_practice.pdf",
RequestBody.create(MediaType.parse("multipart/form-data"),
new File("C:/Users/hetiantian/Desktop/學習/docker_practice.pdf")))
.build();
Request request = new Request.Builder()
.url(url)
.post(requestBody) //默認爲GET請求，可以不寫
.build();
final Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}
通過addFormDataPart方法模擬表單方式上傳文件
DELETE請求：
@Test
public void testDelete() throws IOException {
String url = String.format("%s%s", BASE_URL, api);
//請求參數
Request request = new Request.Builder()
.url(url)
.delete()
.build();
final Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}
請求的取消：
@Test
public void testCancelSysnc() throws IOException {
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
Request request = new Request.Builder()
.url(url)
.get()
.build();
final Call call = client.newCall(request);
Response response = call.execute();
long start = System.currentTimeMillis();
//測試連接的取消
while (true) {
//1分鐘獲取不到結果就取消請求
if (System.currentTimeMillis() - start > 1000) {
call.cancel();
System.out.println("task canceled");
break;
}
}
System.out.println(response.body().string());
}
調用cancel方法進行取消 測試結果：
task canceled
cost 9110 msc
java.net.SocketException: socket closed...【省略】
小結
OkHttp使用build模式創建對象來的更簡潔一些，並且使用.post/.delete/.put/.get方法表示請求類型，不需要像HttpClient創建HttpGet、HttpPost等這些方法來創建請求類型
依賴包上，如果HttpClient需要發送異步請求、實現文件上傳，需要額外的引入異步請求依賴
<!---文件上傳-->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.5.3</version>
</dependency>
<!--異步請求-->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.5.3</version>
</dependency>
請求的取消，HttpClient使用abort方法，OkHttp使用cancel方法，都挺簡單的，如果使用的是異步client，則在拋出異常時調用取消請求的方法即可
超時設置
HttpClient超時設置：
在HttpClient4.3+版本以上，超時設置通過RequestConfig進行設置
private CloseableHttpClient httpClient = HttpClientBuilder.create().build();
private RequestConfig requestConfig = RequestConfig.custom()
.setSocketTimeout(60 * 1000)
.setConnectTimeout(60 * 1000).build();
String api = "/api/files/1";
String url = String.format("%s%s", BASE_URL, api);
HttpGet httpGet = new HttpGet(url);
httpGet.setConfig(requestConfig); //設置超時時間
超時時間是設置在請求類型HttpGet上，而不是HttpClient上
OkHttp超時設置：
直接在OkHttp上進行設置
private OkHttpClient client = new OkHttpClient.Builder()
.connectTimeout(60, TimeUnit.SECONDS)//設置連接超時時間
.readTimeout(60, TimeUnit.SECONDS)//設置讀取超時時間
.build();
小結：
如果client是單例模式，HttpClient在設置超時方面來的更靈活，針對不同請求類型設置不同的超時時間，OkHttp一旦設置了超時時間，所有請求類型的超時時間也就確定
HttpClient和OkHttp性能比較
測試環境：
- CPU 六核
- 內存 8G
- windows10
每種測試用例都測試五次，排除偶然性
client連接爲單例：
client連接不爲單例：
單例模式下，HttpClient的響應速度要更快一些，單位爲毫秒，性能差異相差不大
非單例模式下，OkHttp的性能更好，HttpClient創建連接比較耗時，因爲多數情況下這些資源都會寫成單例模式，因此圖一的測試結果更具有參考價值
總結
OkHttp和HttpClient在性能和使用上不分伯仲，根據實際業務選擇即可
示例代碼
https://github.com/TiantianUpup/http-call