Java StringUtil 用法示例

package com.xx.zhj.Study;



import junit.framework.TestCase;



import org.apache.commons.lang.StringUtils;



public class StringUtilTest extends TestCase {

	  public void testStringUtils()

	    {

	 	// data setup   

	        String str1 = "";   

	        String str2 = " ";   

	        String str3 = "\t";   

	        String str4 = null;   

	        String str5 = "123";   

	        String str6 = "ABCDEFG";   

	        String str7 = "It feels good to use StringUtils \r\n";   

	           

	        // check for empty strings   检查字符串是否为空或null或仅仅包含空格

	        System.out.println("==============================");   

	        System.out.println("Is str1 blank? " + StringUtils.isBlank(str1));   

	        System.out.println("Is str2 blank? " + StringUtils.isBlank(str2));   

	        System.out.println("Is str3 blank? " + StringUtils.isBlank(str3));   

	        System.out.println("Is str4 blank? " + StringUtils.isBlank(str4));   

	           

	        // check for numerics   检查字符串是否仅仅包含数字

	        System.out.println("==============================");   

	        System.out.println("Is str5 numeric? " + StringUtils.isNumeric(str5));   

	        System.out.println("Is str6 numeric? " + StringUtils.isNumeric(str6));   

	           

	        // reverse strings / whole words   

	        System.out.println("==============================");   

	        System.out.println("str6: " + str6);   

	      //字符的全部反转

	        System.out.println("str6 reversed: " + StringUtils.reverse(str6));   

	        System.out.println("str7: " + str7);   

	        String str8 = StringUtils.chomp(str7);   

	        str8 = StringUtils.reverseDelimited(str8, ' ');   

	        System.out.println("str7 reversed whole words : \r\n" + str8);         

	       

	       	// build header (useful to print log messages that are easy to locate)   

	        System.out.println("==============================");   

	        System.out.println("print header:");   

	        String padding = StringUtils.repeat("=", 50); 

	        String msg = StringUtils.center(" Customised Header ", 50, "%");   //使一个字符串居中（在输出的时候）

	        Object[] raw = new Object[]{padding, msg, padding};   

	        String header = StringUtils.join(raw, "\r\n");   

	        System.out.println(header);   

	        

	        //数字前后加入某符号

	        System.out.println(StringUtils.leftPad("34", 8, "0"));

	    }   

}

　输出

==============================

Is str1 blank? true

Is str2 blank? true

Is str3 blank? true

Is str4 blank? true

==============================

Is str5 numeric? true

Is str6 numeric? false

==============================

str6: ABCDEFG

str6 reversed: GFEDCBA

str7: It feels good to use StringUtils 



str7 reversed whole words : 

StringUtils use to good feels It

==============================

print header:

==================================================

%%%%%%%%%%%%%%% Customised Header %%%%%%%%%%%%%%%%

==================================================

00000034