entrySet怎么用的。。。
请求地址:http://localhost:8080/yhrecord/projman/test.jsp?name=sky&age=12
<br> Map<String,String> map=request.getParameterMap();<br> Set<Map.Entry<String, String>> entry=map.entrySet();<br> for(Map.Entry<String,String> entry_:entry){<br> System.out.println(entry_.getKey().toString()+":"+entry_.getValue().toString());<br> }<br>
System.out.println(entry_.getKey().toString()+”:”+entry_.getValue().toString());
这行会报:java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.String
请问怎么破。。。
——解决方案——————–
import java.util.HashMap;<br> import java.util.Map;<br> import java.util.Set;<br><br> public class Test17 {<br><br> public static void main(String[] args) {<br><br> Map<String, String[]> map = new HashMap<String,String[]>();<br> map.put("B", new String[]{"B","C","D"});<br> map.put("A", new String[]{"B","C","D"});<br> Set<Map.Entry<String, String[]>> entry = map.entrySet();<br> for (Map.Entry<String, String[]> entry_ : entry) {<br> System.out.println(entry_.getKey().toString() + ":"<br> + java.util.Arrays.toString(entry_.getValue()));<br> }<br><br> }<br><br> }