java - 简单的java代码行捕获了UnsupportedEncodingException，我不明白为什么

Question

我完全被这个问题困住了。我知道我的代码是正确的。这很简单。我尝试使用 .equals 与 null 进行比较，现在使用 .length()，但它不断捕获此异常。有谁知道这是怎么回事吗？

public static void findLocations(String what, String near, String near2, String type) {
    StringBuilder responseBuilder = new StringBuilder();
    try {
        URL url;
        String tempURL = "http://.........";

        if (what.length() != 0) { // This line is catching UnsupportedEncodingException
            tempURL += "&category=" + URLEncoder.encode(what, "UTF-8");
        }

        if (near.length() != 0) {


Thread [<1> main] (Suspended)   
LocationSet.findLocations(String, String, String, String) line: 85  
SearchAlgorithm.editNear() line: 322    
SearchAlgorithm.search(String, String) line: 90 
SearchView.onClick(View) line: 281  
Button(View).performClick() line: 2408  
View$PerformClick.run() line: 8816  
ViewRoot(Handler).handleCallback(Message) line: 587 
ViewRoot(Handler).dispatchMessage(Message) line: 92 
Looper.loop() line: 123 
ActivityThread.main(String[]) line: 4627    
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
Method.invoke(Object, Object...) line: 521  
ZygoteInit$MethodAndArgsCaller.run() line: 868  
ZygoteInit.main(String[]) line: 626 
NativeStart.main(String[]) line: not available [native method]  

Answer 1

http://download.oracle.com/javase/1.4.2/docs/api/java/net/URLEncoder.html#encode%28java.lang.String,%20java.lang.String%29

public static String encode(String s, String enc) throws UnsupportedEncodingException

方法“URLENCODER.encode(what, "UTF-8") 是在其中出现异常的行。