[网络协议]Java技能树-网络-HTTP-HttpURLConnection

1 需求

2 接口

Class HttpURLConnection

java.lang.Object?
????????java.net.URLConnection?
????????????????java.net.HttpURLConnection?

public abstract class HttpURLConnection extends URLConnection

Field Detail

Constructor Detail

• protected HttpURLConnection(URL u)

Method Detail

• public void setRequestMethod(String method) throws ProtocolException
• public int getResponseCode() throws IOException

Class URLConnection

java.lang.Object?
????????java.net.URLConnection

public abstract class URLConnection extends Object

Field Detail

Constructor Detail

Method Detail

• public InputStream getInputStream() throws IOException
  ?

Class URL

java.lang.Object?
????????java.net.URL

public final class URL extends Object implements Serializable

Constructor Detail

• public URL(String spec) throws MalformedURLException

Method Detail

• public URLConnection openConnection() throws IOException
• public URLConnection openConnection(Proxy proxy) throws IOException

3 示例

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * 第一步，创建远程连接
 * 第二步，设置连接方式（get、post、put。。。）
 * 第三步，设置连接超时时间
 * 第四步，设置响应读取时间
 * 第五步，发起请求
 * 第六步，获取请求数据
 * 第七步，关闭连接
 */
public class Test {
    public static void main(String[] args) {

        StringBuffer result = new StringBuffer();

        try {
            // 创建连接
            URL url = new URL("http://www.dvwa.com/login.php");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            // 设置请求方式
            connection.setRequestMethod("GET");
            // 设置连接超时时间
            connection.setReadTimeout(15000);

            // 开始连接
            connection.connect();

            // 获取请求数据
            if (connection.getResponseCode() == 200) {
                InputStream is = connection.getInputStream();
                if (is != null) {
                    InputStreamReader ir = new InputStreamReader(is, "UTF-8");
                    BufferedReader br = new BufferedReader(ir);
                    String line = null;
                    while ((line = br.readLine()) != null) {
                        result.append(line);
                    }
                }
            }

            //
            connection.disconnect();
        } catch (IOException e) {
            e.printStackTrace();
        }

        System.out.println(result);
    }
}

4 参考资料

java实现调用http请求的几种常见方式_qq_duhai的博客-CSDN博客_java http

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