replaceAll替换字符串中的一个或多个空格

使用replaceAll替换字符串中的一个或多个空格：

package think.in.java.test;

/**
 * 测试replaceAll去除多个空格
 * @author Administrator
 *
 */
public class Test_ReplaceAll {

    public static void main(String args[]) {
        //使用  replaceAll(" +"," ") 匹配一个或多个空格，然后替换成一个空格
        String s1 = "    SELECT     ID,NAME,   CODE FROM    TABLE1 WHERE ID = '0101'    ";
        s1 = s1.replaceAll(" +"," ");
        System.out.println("s1: "+ s1);
        
        //replace则不行
        String s2 = "    SELECT     ID,NAME,   CODE FROM    TABLE1 WHERE ID = '0101'    ";
        s2 = s2.replace(" +", " ");
        System.out.println("s2: " + s2);
    }
}

执行结果：

s1:  SELECT ID,NAME, CODE FROM TABLE1 WHERE ID = '0101' 
s2:     SELECT     ID,NAME,   CODE FROM    TABLE1 WHERE ID = '0101'