ValidateUtil判断字符串工具

package Utils.validate;


import java.io.File;

public class ValidateUtil {

    public static void checkFile(String filePath) {
        File target = new File(filePath);
        if (target.exists()) {
            target.delete();
        }
    }
    
    public static boolean isNotNull(String string) {
        return  string!=null && !("").equals(string.trim()) && !("null").equals(string);
    }
    
    public static boolean NotNvl(String str) {
        return (str != null) && (!("").equals(str.trim()));
    }
    
    public static boolean isNull(String string) {
        
        return  string==null || ("").equals(string.trim()) || ("null").equals(string);
     
    }
}

package Utils.validate;

import org.junit.Test;

public class ValidateTest {

    @Test
    public void test1(){
        System.out.println(ValidateUtil.isNotNull("     "));
        System.out.println(ValidateUtil.isNotNull("www"));
        System.out.println(ValidateUtil.isNull("     "));
    }
}