unknownHostException：无法解析主机“”：没有与主机名关联的地址

Question

我100%肯定电话有互联网连接。我可以浏览网站和连接工作。尽管如此，从我的应用程序中，我看到了这个错误：

java.net.UnknownHostException: Unable to resolve host "<url>": No address associated with hostname

在源代码中，我提供的URL从web浏览器工作，我可以访问它。

更新1：

我试图从应用程序访问的URL的代码：

public static final String MY_URL = CORE_URL + "Panama/products/json_index/";

当我访问存储在my_url中的URL时，我会在web浏览器中看到一个JSON响应：

{"result":"Success","Cities":[{"name":"Panama","slug":"panama-city"},{"name":"Colombia","slug":"Bogota"}]}

Util.requestGetData(Util.MY_URL, this, ResponseListener.REQUEST_MY_CITIES_LIST);

@Override
public void onResponse(final Response r, final int rid) {
    ...
    docment = new JSONObject(r.getData());
    ...
}

更新3：

如果我在使用Android4.x的手机上访问URL，我会得到以下信息：

{"result":"Success","Cities":[{"name":"Panama","slug":"panama-city"},{"name":"Colombia","slug":"Bogota"}]}

URL工作，我有互联网接入和WiFi很好，从我看到的，因为我可以浏览网站，一切正常。也许是断断续续的WiFi？对我来说，一切都很好，有了WiFi和互联网接入也很好。当我使用Android6.x及更高版本的r.getdata()时，应用程序不会出现任何问题。在Android4.x和5.x中发生了什么，我得到了这个错误。奇怪的是，它以前可以工作，但在过去的几周里，它突然停止工作，我根本没有改变代码。

07-01 19:28:58.791 28351-28399/com.myapp D/tag: http://www.google.com
07-01 19:28:59.171 28351-28351/com.myapp D/OpenGLRenderer: Enabling debug mode 0
07-01 19:28:59.171 28351-28351/com.myapp D/ProgressBar: updateDrawableBounds: left = 0
07-01 19:28:59.171 28351-28351/com.myapp D/ProgressBar: updateDrawableBounds: top = 0
07-01 19:28:59.171 28351-28351/com.myapp D/ProgressBar: updateDrawableBounds: right = 72
07-01 19:28:59.171 28351-28351/com.myapp D/ProgressBar: updateDrawableBounds: bottom = 72
07-01 19:28:59.231 28351-28407/com.myapp I/dalvikvm: Could not find method android.content.Context.checkSelfPermission, referenced from method com.urbanairship.analytics.EventApiClient.getLocationPermission
07-01 19:28:59.231 28351-28407/com.myapp W/dalvikvm: VFY: unable to resolve virtual method 138: Landroid/content/Context;.checkSelfPermission (Ljava/lang/String;)I
07-01 19:28:59.231 28351-28407/com.myapp D/dalvikvm: VFY: replacing opcode 0x6e at 0x000c
07-01 19:28:59.431 28351-28351/com.myapp E/ViewRootImpl: sendUserActionEvent() mView == null
07-01 19:28:59.471 28351-28351/com.myapp W/InputMethodManager: Ignoring onBind: cur seq=57, given seq=56

更新5：

07-01 19:36:31.931 28645-28645/com.myapp D/OpenGLRenderer: Enabling debug mode 0
07-01 19:36:31.931 28645-28645/com.myapp D/ProgressBar: updateDrawableBounds: left = 0
07-01 19:36:31.931 28645-28645/com.myapp D/ProgressBar: updateDrawableBounds: top = 0
07-01 19:36:31.931 28645-28645/com.myapp D/ProgressBar: updateDrawableBounds: right = 72
07-01 19:36:31.931 28645-28645/com.myapp D/ProgressBar: updateDrawableBounds: bottom = 72
07-01 19:36:32.011 28645-28705/com.myapp I/dalvikvm: Could not find method android.content.Context.checkSelfPermission, referenced from method com.urbanairship.analytics.EventApiClient.getLocationPermission
07-01 19:36:32.011 28645-28705/com.myapp W/dalvikvm: VFY: unable to resolve virtual method 138: Landroid/content/Context;.checkSelfPermission (Ljava/lang/String;)I
07-01 19:36:32.011 28645-28705/com.myapp D/dalvikvm: VFY: replacing opcode 0x6e at 0x000c
07-01 19:36:32.031 28645-28698/com.myapp W/System.err: javax.net.ssl.SSLPeerUnverifiedException: No peer certificate
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at com.android.org.conscrypt.SSLSessionImpl.getPeerCertificates(SSLSessionImpl.java:146)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.conn.ssl.AbstractVerifier.verify(AbstractVerifier.java:93)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.conn.ssl.SSLSocketFactory.createSocket(SSLSocketFactory.java:388)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:165)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
07-01 19:36:32.031 28645-28698/com.myapp W/System.err:     at com.myapp.Util.Util$1.run(Util.java:242)
07-01 19:36:32.041 28645-28698/com.myapp W/System.err:     at java.lang.Thread.run(Thread.java:841)
07-01 19:36:32.251 28645-28645/com.myapp E/ViewRootImpl: sendUserActionEvent() mView == null
07-01 19:36:32.301 28645-28645/com.myapp W/InputMethodManager: Ignoring onBind: cur seq=60, given seq=59

现在我一直看到这个错误，java.net.unknownHostException：无法解析主机“ ”：与主机名相关联的地址 再也不会出现在Android Studio Logcat中：

07-02 09:30:15.468 9350-9391/com.myapp W/System.err: javax.net.ssl.SSLPeerUnverifiedException: No peer certificate
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at com.android.org.conscrypt.SSLSessionImpl.getPeerCertificates(SSLSessionImpl.java:146)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.conn.ssl.AbstractVerifier.verify(AbstractVerifier.java:93)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.conn.ssl.SSLSocketFactory.createSocket(SSLSocketFactory.java:388)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:165)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at com.myapp.Util.Util$1.run(Util.java:242)
07-02 09:30:15.478 9350-9391/com.myapp W/System.err:     at java.lang.Thread.run(Thread.java:841)
07-02 09:30:15.628 9350-9350/com.myapp E/ViewRootImpl: sendUserActionEvent() mView == null
07-02 09:30:15.668 9350-9350/com.myapp W/InputMethodManager: Ignoring onBind: cur seq=77, given seq=76

也许真正的问题是SSL证书，它与WiFi问题或我正在使用的URL的可用性无关？

Answer 1

我想我现在需要结束这个问题，因为它已经与另一个问题直接相关：javax.net.ssl.sslpeerunverifiedException：在Android4.x和5.x上没有对等证书。因此，对另一个问题的解决方案也将成为对这个问题的解决方案。