Host name may not be null problem

            
java.lang.IllegalArgumentException: Host name may not be null
Address no problem accessing do not know why there is this problem, seek help heroes.

The address is synthetic "htt :/ /" + xxx + "com" is obtained from the above problems xxx server side, then go visit this address will appear above problems, if not dead, then write xxx there. Addresses are the same, just do not know why there is this problem seek help
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Xxx is how you get that? It should not get to that xxx
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xxx is a network server through httpget acquired. Obtained before accessing the url output with no problem. But do not know why this exception will be reported
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Still feel further than to look after the string synthesis, see, and there is no written death subtle differences
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And death is written exactly the same
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Set breakpoints, ah, it is estimated that before you put the url request the assignment of the network, resulting in xxx is empty.
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xxx print it out and have no problem with url
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A few bars of it ... a closer look
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htt:? ? p where to go? ?

Determine whether the same two characters do not see with your eyes, and then print directly return value equals the value of the function