java数组使用技巧

参考网上文章，总结了一下java数组使用技巧，如下：

package com.beijing.array;



import java.nio.ByteBuffer;

import java.util.Arrays;

import java.util.HashSet;

import java.util.Set;



import org.apache.commons.lang.ArrayUtils;



/**

 * 

 * @description java数组使用技巧

 * @author liuchao

 * @createTime 2013年10月10日上午10:27:15

 */

public class ArrayTest {



	public static void main(String[] args) {



		// 1.声明数组

		/*

		 * String[] a = new String[5]; String[] b = {"a","b","c","d","e"};

		 * String[] c = new String[]{"a","b","c","d","e"};

		 */



		// 2.在java中输出一个数组

		/*

		 * int[] intArray = {1,2,3,4,5}; String intArrayString =

		 * Arrays.toString(intArray);

		 * 

		 * System.out.println(intArray);//[I@de6ced

		 * System.out.println(intArrayString);//[1, 2, 3, 4, 5]

		 */



		// 3.从数组中创建列表

		/*

		 * String[] stringArray = {"a","b","c","d","e"}; ArrayList<String>

		 * arrayList = new ArrayList<String>(Arrays.asList(stringArray));

		 * System.out.println(arrayList);//[a, b, c, d, e]

		 */



		// 4.检查数组中是否包含特定值

		/*

		 * String[] stringArray = {"a","b","c","d","e"}; boolean b =

		 * Arrays.asList(stringArray).contains("a");

		 * System.out.println(b);//true

		 */

		// 5.连接连个数组

		/*

		 * int[] intArray = {1,2,3,4,5}; int[] intArray2 = {6,7,8,9,10};

		 * 

		 * //use apache commons lang library int[] combinedIntArray =

		 * ArrayUtils.addAll(intArray, intArray2); for (int i = 0; i <

		 * combinedIntArray.length; i++) {

		 * System.out.print(combinedIntArray[i]+","); }

		 * 

		 * //1,2,3,4,5,6,7,8,9,10,

		 */

		// 6.将数组元素加入到一个独立的字符串中（即用独立的字符串分割数组元素）

		/*

		 * String str = StringUtils.join(new String[]{"a","b","c"}, ",");

		 * System.out.println(str);//a,b,c

		 */

		

		//7.将数组列表转换成一个数组

		/*String[] stringArray = { "a", "b", "c", "d", "e" };

		ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));

		

		String[] stringArr = new String[arrayList.size()];

		arrayList.toArray(stringArr);

		

		for(String s : stringArr){

			 System.out.println(s);

		}*/

		

		

		

		//8.将数组转换成一个集合

		/*String[] stringArray = { "a", "b", "c", "d", "e" };

		Set<String> set = new HashSet<String>(Arrays.asList(stringArray));

		System.out.println(set);//[d, e, b, c, a]

*/		

		

		//9.反向数组

		/*int[] intArray = {1,2,3,4,5};

		ArrayUtils.reverse(intArray);

		System.out.println(Arrays.toString(intArray));//[5, 4, 3, 2, 1]

*/		

		

		//10.删除数组元素

		/*int[] intArray = {1,34,3,2,56,13,13,45,2};

		int[] removed = ArrayUtils.removeElement(intArray, 2);//删除第一个匹配的元素

		System.out.println(Arrays.toString(removed));*/

		

		//11.把整数转换成字节数组

		/*byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();

		   

		for (byte t : bytes) {

		   System.out.format("0x%x ", t);//0x0 0x0 0x0 0x8

		}*/

		

		//一个整数与0xFF进行&操作，得到该整数的二进制表示

		

		/*ByteBuffer buffer = ByteBuffer.allocate(1024); //分配一定的空间,1024

		int i = 90;

		buffer.putInt(i);

		byte[] array = buffer.array(); //获取该buffer的数组,这个数组是跟该buffer一一对应的

		for(int j =0; j <4;j++){

			System.out.println(Integer.toBinaryString(array[j] & 0xFF));//1011010

		}*/



		

	}

}