Java GET 请求没有协议(protocol)？

Question

我已经向我的本地主机发出了 GET 请求(只是测试一些东西)，但我不断收到此错误!

java.net.MalformedURLException: no protocol: localhost/register.php?username=chris&password=chris&email=chris@gmail.com
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at com.mcmonitor.sys.HttpUtility.sendGetRequest(HttpUtility.java:34)
at com.mcmonitor.sys.Main.sendGet(Main.java:28)
at com.mcmonitor.screens.LoginScreen$3.actionPerformed(LoginScreen.java:94)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

这是什么？下面是发送 GET 请求的方法:

public static HttpURLConnection sendGetRequest(String requestURL)
    throws IOException {
    URL url = new URL(requestURL);
    httpConn = (HttpURLConnection) url.openConnection();
    httpConn.setUseCaches(false);
    httpConn.setDoInput(true); // true if we want to read server's response
    httpConn.setDoOutput(false); // false indicates this is a GET request
    return httpConn;
}

从互联网上复制的，因为我已经尝试了 20 分钟了。有人能解释一下吗？非常感谢

顺便说一句，这是请求:localhost/register.php?用户名=chris&密码=chris&email=chris@gmail.com

Answer 1

java.net.MalformedURLException: no protocol: localhost/register.php?

这告诉您需要一个协议(protocol)(例如 HTTP 或 HTTPS)。将您的请求更改为 http://localhost/register.php?...。 Java 与 Chrome 不同，它会推断出您指的是 http/s。您必须提供完整的 URL。