用java语言完成1、运用URLConnection类下载一个WEB页面。 2、运用URLConnection类以正确的字符集下载一个web页面。 3、运用URLConnection类显示整个HTTP首部。
时间: 2024-06-10 15:05:19 浏览: 10
回答:
您好,我会尽力回答您的问题。我理解您需要在Java中使用URLConnection类来下载一个WEB页面,并且按照正确的字符集显示整个HTTP首部。以下是一些示例代码来完成这些任务:
1、下载一个WEB页面:
```java
import java.io.*;
import java.net.*;
public class DownloadWebpage {
public static void main(String[] args) throws Exception {
URL url = new URL("http://www.example.com");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream inputStream = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
reader.close();
}
}
```
2、以正确的字符集下载一个web页面:
```java
import java.io.*;
import java.net.*;
public class DownloadWebpageWithCharset {
public static void main(String[] args) throws Exception {
URL url = new URL("http://www.example.com");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
String charset = "UTF-8"; // 设置字符集为UTF-8,可根据需求更改
InputStream inputStream = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, charset));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
reader.close();
}
}
```
3、显示整个HTTP首部:
```java
import java.io.*;
import java.net.*;
public class DisplayHTTPHeaders {
public static void main(String[] args) throws Exception {
URL url = new URL("http://www.example.com");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
for (int i = 0;; i++) {
String headerName = conn.getHeaderFieldKey(i);
String headerValue = conn.getHeaderField(i);
if (headerName == null && headerValue == null) {
break;
}
System.out.println(headerName + ": " + headerValue);
}
}
}
```
这些示例代码可以帮助您完成您提供的任务。如果您还有其他问题,请随时问我。