从网址获取http响应代码

Question

我想编写一个Java程序，它将点击一个URL并打印状态代码（即200,404等）。 我这样做是使用HttpUrlConnection api，但它只显示异常，并且不打印状态代码。

URL url = new URL("https://abc.com/test.html");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.connect();

int code = connection.getResponseCode();  
System.out.println("code: "+code);

Answer 1

我尝试了你的代码如下，它对我来说很好：

import java.net.*;

public class Action 
{

    public static void main(String[] args)
    {
        try
        {
            URL url = new URL("http://localhost:8888");
            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();

            int code = connection.getResponseCode();  
            System.out.println("code: "+code);
        }
        catch(Exception e)
        {

        }

    }
}

还有谷歌。

Answer 2

只有当您能够访问该URL时，您才会从URL获得响应代码。 在您的代码中，您似乎使用的是非现有URL，因此必须获得无法访问的主机异常。

尝试访问有效的URL并检查响应代码：

URL url = new URL("https://google.com");

Answer 3

URL url = new URL("https://www.google.com");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.connect();

int code = connection.getResponseCode();  
System.out.println("code: "+code);

尝试使用其他网址，因为您使用的网址无效。 ' https://abc.com/test.html ' - 不存在此类页面，因此它提供了异常。 尝试一个有效的网址，它会正常工作。

Answer 4

即使我得到相同的异常，即java.net.ConnectException：连接超时：如果我没有在您的代码中添加代理和端口连接。

java.net.ConnectException: Connection timed out: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(Unknown Source)
    at com.sun.net.ssl.internal.ssl.BaseSSLSocketImpl.connect(Unknown Source)
    at sun.net.NetworkClient.doConnect(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
    at edu.sandip.TestURLConnection.main(TestURLConnection.java:23)

您获得此异常是因为您在组织代理后面的组织上执行代码。

请使用以下修改后的代码。 你将得到200 OK作为responseCode。

    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.net.URLConnection;

    import javax.net.ssl.HttpsURLConnection;



    public class TestURLConnection {

        /**
         * @param args
         */
        public static void main(String[] args) {
            try{
                URL url = new URL("https://www.google.com/");
                System.setProperty("https.proxyHost", "XXX.XXX.XXX.XX");
                System.setProperty("https.proxyPort", "80"); 
                HttpURLConnection connection = (HttpURLConnection)url.openConnection();
                //HttpsURLConnection connection = (HttpsURLConnection)url.openConnection();
                connection.setRequestMethod("GET");
                connection.connect();

                int code = connection.getResponseCode();  
                System.out.println("code: "+code);
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }

注意：1。您需要从组织网络管理员处获取proxyHost IP。 2.您应该使用HttpsURLConnection访问https URL。