学步园

项目里用到了一些数组排序，求和的方法，总算是有点自己的成果，不用总算COPY别人的过来了。import java.util.Arrays;<br /> import java.util.ArrayList;<br /> import java.util.Collections;<br /> import java.util.Comparator;<br /> import java.util.Iterator;<br /> import java.util.LinkedHashMap;<br /> import java.util.List;<br /> import java.util.Map;</p> <p>public class MyTools {</p> <p> /**<br /> * 字符串转换成整型数组<br /> * @param str String<br /> * @return result int[]<br /> */<br /> public int[] stringToIntArray(String str){ </p> <p> int[] result = new int[str.length()-1];</p> <p> for(int i=0;i<str.split(",").length;i++){ </p> <p> result[i] = Integer.valueOf(str.split(",")[i].toString());<br /> }</p> <p> return result;<br /> }</p> <p> /**<br /> * 字符串数组转换成用“--”连接的字符串<br /> * @param str String[]<br /> * @return result String<br /> */<br /> public String strArrayToString(String[] array){ </p> <p> String str = "--";<br /> String result = new String();</p> <p> if(array!=null&&array.length>0){ </p> <p> result = java.util.Arrays.toString(array);<br /> result = result.substring(1,result.length()-1); </p> <p> }<br /> result = str+ result.replace(", ", "--");<br /> return result;<br /> }</p> <p> /**<br /> * 整型数组转换成用“--”连接的字符串<br /> * @param array int[]<br /> * @return result String<br /> */<br /> public String arrayToString(int[] array){ </p> <p> String str = "--";<br /> String result = "";</p> <p> if(array!=null&&array.length>0){ </p> <p> result = java.util.Arrays.toString(array);<br /> result = result.substring(1,result.length()-1);<br /> result = str+ result.replace(", ", "--");<br /> }<br /> return result;<br /> } </p> <p> /**<br /> * 数组元素求和<br /> * @param array int[]<br /> * @return result int<br /> */<br /> public int addNumbers(int[] array){ </p> <p> int result = 0;</p> <p> if(array!=null&&array.length>0){</p> <p> for(int i=0;i< array.length;i++){</p> <p> result = result+array[i];<br /> }<br /> }</p> <p> return result;<br /> } </p> <p> /**<br /> * 去除字符串数组中重复元素<br /> * @param array String[]<br /> * @return result String[]<br /> */<br /> public String[] getDistinctStr(String[] array){ </p> <p> ArrayList list=new ArrayList(); </p> <p> for(int i=0;i<array.length;i++) { </p> <p> if(!list.contains(array[i])) {</p> <p> list.add(array[i]);<br /> }<br /> } </p> <p> String[] result=new String[list.size()]; </p> <p> for(int i=0;i<result.length;i++){</p> <p> result[i] = (String)list.get(i);<br /> }<br /> return result;<br /> }</p> <p> /**<br /> * 数组排序并且取前topNum项返回<br /> * @param array int[]<br /> * @param topNum int<br /> * @return result int[]<br /> */<br /> public int[] arraySort(int[] array,int topNum){ </p> <p> ArrayList list=new ArrayList(); </p> <p> Arrays.sort(array);</p> <p> for(int i=array.length-1;i>=array.length-topNum;i--){</p> <p> list.add(array[i]);<br /> } </p> <p> int[] result=new int[list.size()]; </p> <p> for(int i=0;i<list.size();i++){</p> <p> result[i] = Integer.valueOf(list.get(i).toString());<br /> }<br /> return result;<br /> }</p> <p> /**<br /> * 字符串数组取前topNum项返回<br /> * @param array String[]<br /> * @param topNum int<br /> * @return result String[]<br /> */<br /> public String[] topStrArray(String[] array,int topNum){ </p> <p> ArrayList list=new ArrayList(); </p> <p> if (topNum >array.length){</p> <p> topNum = array.length;</p> <p> }<br /> for(int i=0;i<topNum;i++){</p> <p> list.add(array[i]);<br /> } </p> <p> String[] result=new String[list.size()]; </p> <p> for(int i=0;i<list.size();i++){</p> <p> result[i] = list.get(i).toString();<br /> }<br /> return result;<br /> }</p> <p> /**<br /> * LinkedHashMap排序并且取前topNum项返回<br /> * @param topMap LinkedHashMap<String, Integer><br /> * @param topNum int<br /> * @return resultStrArray String[]<br /> */<br /> public String[] MapSort(LinkedHashMap<String, Integer> topMap,int topNum){ </p> <p> LinkedHashMap<String, Integer> result = new LinkedHashMap<String, Integer>();<br /> int StrIndex = 0;<br /> List<Map.Entry<String, Integer>> topMapList =<br /> new ArrayList<Map.Entry<String, Integer>>(topMap.entrySet()); </p> <p> /**<br /> * 排序<br /> */<br /> Collections.sort(topMapList, new Comparator<Map.Entry<String, Integer>>() { </p> <p> public int compare(Map.Entry<String, Integer> topMapObj1,<br /> Map.Entry<String, Integer> topMapObj2) {<br /> return (topMapObj2.getValue() - topMapObj1.getValue());<br /> }<br /> }); </p> <p> if (topNum >topMap.size()){</p> <p> topNum = topMap.size();<br /> }</p> <p> /**<br /> * 将排序后结果放回一个新的LinkedHashMap中<br /> */<br /> for (int i = 0; i<topNum; i++) {</p> <p> result.put(topMapList.get(i).getKey(),topMapList.get(i).getValue());<br /> }</p> <p> String[] resultStrArray = new String[result.size()];</p> <p> Iterator it = result.entrySet().iterator();</p> <p> /**<br /> * 将LinkedHashMap中的内容放到数组中<br /> */<br /> while (it.hasNext()) {</p> <p> Map.Entry entry = (Map.Entry) it.next();</p> <p> resultStrArray[StrIndex] = entry.getKey().toString();<br /> StrIndex++;<br /> }</p> <p> return resultStrArray;<br /> }<br /> }<br />