20非常有用的Java程序片段(19-20)

19. 發送代數據的HTTP 請求

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importjava.io.BufferedReader;   importjava.io.InputStreamReader;   importjava.net.URL;   publicclassMain {   publicstaticvoidmain(String[] args)  {   try{   URL my_url = newURL("http://coolshell.cn/");   BufferedReader br = newBufferedReader(newInputStreamReader(my_url.openStream()));   String strTemp = "";   while(null!= (strTemp = br.readLine())){   System.out.println(strTemp);   }   } catch(Exception ex) {   ex.printStackTrace();   }   }   }

20. 改變數組的大小

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/** * Reallocates an array with a new size, and copies the contents * of the old array to the new array. * @param oldArray  the old array, to be reallocated. * @param newSize   the new array size. * @return          A new array with the same contents. */ privatestaticObject resizeArray (Object oldArray, intnewSize) {   intoldSize = java.lang.reflect.Array.getLength(oldArray);   Class elementType = oldArray.getClass().getComponentType();   Object newArray = java.lang.reflect.Array.newInstance(   elementType,newSize);   intpreserveLength = Math.min(oldSize,newSize);   if(preserveLength > 0)   System.arraycopy (oldArray,0,newArray,0,preserveLength);   returnnewArray;   }   // Test routine for resizeArray().   publicstaticvoidmain (String[] args) {   int[] a = {1,2,3};   a = (int[])resizeArray(a,5);   a[3] = 4;   a[4] = 5;   for(inti=0; i<a.length; i++)   System.out.println (a[i]);   }