try (CloseableHttpClient httpClient = HttpClients.createDefault())
时间: 2024-01-17 18:17:53 浏览: 31
这段代码是使用Java语言中的try-with-resources语法来创建一个CloseableHttpClient对象。try-with-resources语法可以确保在代码块执行完毕后,自动关闭资源,无需手动调用close()方法。在这个例子中,创建了一个CloseableHttpClient对象httpClient,并使用HttpClients.createDefault()方法进行初始化。接下来可以在try代码块中使用httpClient对象进行HTTP请求操作。当try代码块执行完毕后,httpClient对象会自动关闭。
范例:
```java
try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
// 在这里可以使用httpClient对象进行HTTP请求操作
// ...
} catch (Exception e) {
// 异常处理
// ...
}
```
相关问题
CloseableHttpClient httpClient = HttpClients.createDefault();
`CloseableHttpClient httpClient = HttpClients.createDefault();`是使用Apache HttpClient库创建一个默认的可关闭的HttpClient对象的代码。这个对象可以用来发送HTTP请求并与服务器进行通信。
这是一个简单的示例代码:
```java
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
public class HttpClientExample {
public static void main(String[] args) {
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet("http://www.example.com");
try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
// 处理响应
System.out.println(response.getStatusLine());
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
这个示例中,我们创建了一个默认的HttpClient对象,并使用HttpGet方法创建了一个GET请求。然后,我们使用`httpClient.execute(httpGet)`方法发送请求并获取响应。最后,我们可以处理响应,例如打印响应状态行。
优化这段代码@PostMapping("/login") @ResponseBody @PassToken public Object login(String username,String password) throws IOException { String url="http://42.177.95.222:9202/platform/yugang/task/getToken"; HttpClient client = HttpClients.createDefault(); //默认post请求 HttpPost post = new HttpPost(url); //拼接多参数 JSONObject json = new JSONObject(); json.put("username", "渔业协会"); json.put("password", "Yuye!@#qwe"); post.addHeader("Content-type", "application/json; charset=utf-8"); post.setHeader("Accept", "application/json"); post.setEntity(new StringEntity(json.toString(), Charset.forName("utf-8"))); HttpResponse httpResponse = client.execute(post); HttpEntity entity = httpResponse.getEntity(); String s = EntityUtils.toString(entity); JSONObject jo = JSONObject.parseObject(s); String token = jo.getJSONObject("data").getString("token"); System.out.println("dsadasdasdsadasd"+token); return verify(token); } public Object verify(String token) throws IOException { String url="http://42.177.95.222:9202/platform/yugang/task/verify"; HttpClient client = HttpClients.createDefault(); //默认post请求 HttpPost post = new HttpPost(url); //拼接多参数 JSONObject json = new JSONObject(); json.put("token",token); post.addHeader("Content-type", "application/json; charset=utf-8"); post.setHeader("Accept", "application/json"); post.setEntity(new StringEntity(json.toString(), Charset.forName("utf-8"))); HttpResponse httpResponse = client.execute(post); HttpEntity entity = httpResponse.getEntity(); String s = EntityUtils.toString(entity); JSONObject jo = JSONObject.parseObject(s); return jo; }
这段代码的优化点有以下几个:
1. 将重复的代码抽取成公共方法,避免代码冗余。
2. 使用连接池管理 HttpClient 的连接,提高连接的复用率和性能。
3. 使用 try-with-resources 语句关闭 HttpClient 和 HttpEntity 对象,避免资源泄漏。
下面是代码优化后的示例:
```
private static final String BASE_URL = "http://42.177.95.222:9202/platform/yugang/task";
private CloseableHttpClient httpClient = HttpClientBuilder.create()
.setMaxConnTotal(200)
.setMaxConnPerRoute(100)
.build();
@PostMapping("/login")
@ResponseBody
@PassToken
public Object login(String username, String password) throws IOException {
String token = getToken();
System.out.println("dsadasdasdsadasd" + token);
return verify(token);
}
private String getToken() throws IOException {
String url = BASE_URL + "/getToken";
HttpPost post = new HttpPost(url);
post.addHeader("Content-type", "application/json; charset=utf-8");
post.setHeader("Accept", "application/json");
JSONObject json = new JSONObject();
json.put("username", "渔业协会");
json.put("password", "Yuye!@#qwe");
post.setEntity(new StringEntity(json.toString(), Charset.forName("utf-8")));
try (CloseableHttpResponse response = httpClient.execute(post)) {
HttpEntity entity = response.getEntity();
if (entity != null) {
String s = EntityUtils.toString(entity);
JSONObject jo = JSONObject.parseObject(s);
return jo.getJSONObject("data").getString("token");
}
return null;
}
}
private JSONObject verify(String token) throws IOException {
String url = BASE_URL + "/verify";
HttpPost post = new HttpPost(url);
post.addHeader("Content-type", "application/json; charset=utf-8");
post.setHeader("Accept", "application/json");
JSONObject json = new JSONObject();
json.put("token", token);
post.setEntity(new StringEntity(json.toString(), Charset.forName("utf-8")));
try (CloseableHttpResponse response = httpClient.execute(post)) {
HttpEntity entity = response.getEntity();
if (entity != null) {
String s = EntityUtils.toString(entity);
return JSONObject.parseObject(s);
}
return null;
}
}
```
在优化后的代码中,我们将 HttpClient 对象的创建和关闭都放在了方法外部,使用连接池管理 HttpClient 的连接,提高连接的复用率和性能。同时,我们也将 getToken 和 verify 方法抽取出来,避免了代码冗余。最后,我们使用了 try-with-resources 语句来关闭 HttpClient 和 HttpEntity 对象,避免了资源泄漏。