我应该如何解决 java.lang.IllegalArgumentException: protocol = https host = null Exception？
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How should I resolve java.lang.IllegalArgumentException: protocol = https host = null Exception?
提问by Chathuranga Chandrasekara
I am working on a SSL client server program and I have to reuse the following method.
我正在开发一个 SSL 客户端服务器程序，我必须重用以下方法。
private boolean postMessage(String message){
try{
String serverURLS = getRecipientURL(message);
serverURLS = "https:\\abc.my.domain.com:55555\update";
if (serverURLS != null){
serverURL = new URL(serverURLS);
}
HttpsURLConnection conn = (HttpsURLConnection)serverURL.openConnection();
conn.setHostnameVerifier(new HostnameVerifier() {
public boolean verify(String arg0, SSLSession arg1) {
return true;
}
});
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
OutputStreamWriter wr = new OutputStreamWriter(os);
wr.write(message);
wr.flush();
if (conn.getResponseCode() != HttpsURLConnection.HTTP_OK)
return false;
else
return true;
}
Here ServerURL is initialized as
这里 ServerURL 被初始化为
private URL serverURL = null;
When I try to execute this method I get an exception at Line,
当我尝试执行此方法时，我在 Line 处遇到异常，
OutputStream os = conn.getOutputStream();
OutputStream os = conn.getOutputStream();
The exception is
例外是
java.lang.IllegalArgumentException: protocol = https host = null
What is the reason for this?
这是什么原因？
采纳答案by Aaron Digulla
URLs use forward slashes (/), not backward ones (as windows). Try:
URL 使用正斜杠 (/)，而不是反斜杠（作为窗口）。尝试：
serverURLS = "https://abc.my.domain.com:55555/update";
The reason why you get the error is that the URL class can't parse the host part of the string and therefore, hostis null.
出现错误的原因是 URL 类无法解析字符串的主机部分，因此host是null.
回答by matt b
This code seems completely unnecessary:
这段代码似乎完全没有必要：
String serverURLS = getRecipientURL(message);
serverURLS = "https:\\abc.my.domain.com:55555\update";
if (serverURLS != null){
serverURL = new URL(serverURLS);
}
serverURLSis assigned the result ofgetRecipientURL(message)- Then immediately you overwrite the value of
serverURLS, making the previous statement a dead store - Then, because
if (serverURLS != null)evaluates totrue, since you justassigned the variable a value in the preceding statement, you assign a value toserverURL. It is impossible forif (serverURLS != null)to evaluate tofalse! - You never actually use the variable
serverURLSbeyond the previous line of code.
serverURLS被赋值为getRecipientURL(message)- 然后立即覆盖 的值
serverURLS，使之前的语句成为死存储 - 然后，因为
if (serverURLS != null)计算结果为true，因为您刚刚在前面的语句中为变量分配了一个值，所以您为 分配了一个值serverURL。无法if (serverURLS != null)评价false！ - 您实际上从未使用过
serverURLS前一行代码之外的变量。
You could replace all of this with just:
您可以将所有这些替换为：
serverURL = new URL("https:\\abc.my.domain.com:55555\update");
