java代码怎么获取请求的header
时间: 2024-02-18 19:59:56 浏览: 20
在Java中,可以通过HttpServletRequest对象的getHeader()方法来获取请求的header。例如,以下代码可以获取名为"User-Agent"的header:
``` java
String userAgent = request.getHeader("User-Agent");
```
类似地,你可以使用getHeader()方法获取其他header,例如"Accept-Language"、"Authorization"等。
相关问题
java代码http请求
以下是Java中发送HTTP请求的两种方式:
1.使用HttpURLConnection发送HTTP请求
```java
import java.net.HttpURLConnection;
import java.net.URL;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class HttpURLConnectionExample {
public static void main(String[] args) {
try {
URL url = new URL("http://www.example.com");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/json");
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println(output);
}
conn.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
2.使用HttpClient发送HTTP请求
```java
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class HttpClientExample {
public static void main(String[] args) {
try {
HttpClient client = HttpClientBuilder.create().build();
HttpGet request = new HttpGet("http://www.example.com");
request.addHeader("User-Agent", "Mozilla/5.0");
HttpResponse response = client.execute(request);
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer result = new StringBuffer();
String line = "";
while ((line = rd.readLine()) != null) {
result.append(line);
}
System.out.println(result.toString());
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
java中httpservletrequest获取header
中的参数应该怎么做?
您可以使用HttpServletRequest的getHeader()方法来获取HTTP请求头部的参数。例如,若要获取名为"User-Agent"的请求头参数,请使用以下代码:
```
String userAgent = request.getHeader("User-Agent");
```
在上面的代码中,request是一个HttpServletRequest对象,userAgent变量将保存"User-Agent"请求头部参数的值。
另外,如果您要获取所有的请求头部参数,您可以使用以下代码:
```
Enumeration<String> headerNames = request.getHeaderNames();
while(headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
String headerValue = request.getHeader(headerName);
// 处理请求头部参数
}
```
在上面的代码中,headerNames对象包含所有HTTP请求头部参数的名称,我们可以通过遍历来获取它们,并使用request.getHeader()方法来获取每个参数的值。