isEmpty系列

StringUtils.isEmpty()

是否为空. 可以看到 “ “ 空格是会绕过这种空判断,因为是一个空格,并不是严格的空值,会导致 isEmpty(“ “)=false

  1. StringUtils.isEmpty(null) = true
  2. StringUtils.isEmpty("") = true
  3. StringUtils.isEmpty(" ") = false
  4. StringUtils.isEmpty("bob") = false
  5. StringUtils.isEmpty(" bob ") = false
  1. /**
  2.  *
  3.  * <p>NOTE:This method changed in Lang version 2.0. 
  4.  * It no longer trims the CharSequence. 
  5.  * That functionality is available in isBlank().</p> 
  6.  * 
  7.  * @paramcs the CharSequence to check, may be null 
  8.  * @return{@codetrue} if the CharSequence is empty or null 
  9.  * @since3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence) 
  10.  */
  11. publicstaticbooleanisEmpty(finalCharSequence cs){
  12.     returncs ==null|| cs.length() ==0;
  13. }

StringUtils.isNotEmpty()

相当于不为空 , = !isEmpty()

  1. publicstaticbooleanisNotEmpty(finalCharSequence cs){
  2.     return!isEmpty(cs);
  3. }

StringUtils.isAnyEmpty()

是否有一个为空,只有一个为空,就为true.

  1. StringUtils.isAnyEmpty(null) =true
  2. StringUtils.isAnyEmpty(null,"foo") =true
  3. StringUtils.isAnyEmpty("","bar") =true
  4. StringUtils.isAnyEmpty("bob","") =true
  5. StringUtils.isAnyEmpty("bob ",null) =true
  6. StringUtils.isAnyEmpty(" ","bar") =false
  7. StringUtils.isAnyEmpty("foo","bar") =false
  8. /** 
  9.  * @paramcss the CharSequences to check, may be null or empty 
  10.  * @return{@codetrue} if any of the CharSequences are empty or null 
  11.  * @since3.2 
  12.  */
  13. publicstaticbooleanisAnyEmpty(finalCharSequence... css){
  14.     if(ArrayUtils.isEmpty(css)) {
  15.         returntrue;
  16.     }
  17.     for(finalCharSequence cs : css){
  18.         if(isEmpty(cs)) {
  19.             returntrue;
  20.         }
  21.     }
  22.     returnfalse;
  23. }

StringUtils.isNoneEmpty()

相当于!isAnyEmpty(css) , 必须所有的值都不为空才返回true

  1. /** 
  2.  * <p>Checks if none of the CharSequences are empty ("") or null.</p> 
  3.  * 
  4.  * <pre> 
  5.  * StringUtils.isNoneEmpty(null) = false 
  6.  * StringUtils.isNoneEmpty(null, "foo") = false 
  7.  * StringUtils.isNoneEmpty("", "bar") = false 
  8.  * StringUtils.isNoneEmpty("bob", "") = false 
  9.  * StringUtils.isNoneEmpty(" bob ", null) = false 
  10.  * StringUtils.isNoneEmpty(" ", "bar") = true 
  11.  * StringUtils.isNoneEmpty("foo", "bar") = true 
  12.  * </pre> 
  13.  * 
  14.  * @param css the CharSequences to check, may be null or empty 
  15.  * @return {@code true} if none of the CharSequences are empty or null 
  16.  * @since 3.2 
  17.  */
  18. public static boolean isNoneEmpty(final CharSequence... css) {

isBank系列

StringUtils.isBlank()

是否为真空值(空格或者空值)

  1. StringUtils.isBlank(null) =true
  2. StringUtils.isBlank("") =true
  3. StringUtils.isBlank(" ") =true
  4. StringUtils.isBlank("bob") =false
  5. StringUtils.isBlank("bob ") =false
  1. /** 
  2.  * <p>Checks if a CharSequence is whitespace, empty ("") or null.</p> 
  3.  * @paramcs the CharSequence to check, may be null 
  4.  * @return{@codetrue} if the CharSequence is null, empty or whitespace 
  5.  * @since2.0 
  6.  * @since3.0 Changed signature from isBlank(String) to isBlank(CharSequence) 
  7.  */
  8. publicstaticbooleanisBlank(finalCharSequence cs){
  9.     intstrLen;
  10.     if(cs ==null|| (strLen = cs.length()) ==0) {
  11.         returntrue;
  12.     }
  13.     for(inti =0; i < strLen; i++) {
  14.         if(Character.isWhitespace(cs.charAt(i)) ==false) {
  15.             returnfalse;
  16.         }
  17.     }
  18.     returntrue;
  19. }

StringUtils.isNotBlank()

是否真的不为空,不是空格或者空值 ,相当于!isBlank();

  1. publicstaticbooleanisNotBlank(finalCharSequence cs){
  2.     return!isBlank(cs);
  3. }

StringUtils.isAnyBlank()

是否包含任何真空值(包含空格或空值)

  1. StringUtils.isAnyBlank(null) =true
  2. StringUtils.isAnyBlank(null,"foo") =true
  3. StringUtils.isAnyBlank(null,null) =true
  4. StringUtils.isAnyBlank("","bar") =true
  5. StringUtils.isAnyBlank("bob","") =true
  6. StringUtils.isAnyBlank("bob ",null) =true
  7. StringUtils.isAnyBlank(" ","bar") =true
  8. StringUtils.isAnyBlank("foo","bar") =false
  1. /** 
  2.  * <p>Checks if any one of the CharSequences are blank ("") or null and not whitespace only..</p> 
  3.  * @paramcss the CharSequences to check, may be null or empty 
  4.  * @return{@codetrue} if any of the CharSequences are blank or null or whitespace only 
  5.  * @since3.2 
  6.  */
  7. publicstaticbooleanisAnyBlank(finalCharSequence... css){
  8.     if(ArrayUtils.isEmpty(css)) {
  9.         returntrue;
  10.     }
  11.     for(finalCharSequence cs : css){
  12.         if(isBlank(cs)) {
  13.             returntrue;
  14.         }
  15.     }
  16.     returnfalse;
  17. }

StringUtils.isNoneBlank()

是否全部都不包含空值或空格

  1. StringUtils.isNoneBlank(null) =false
  2. StringUtils.isNoneBlank(null,"foo") =false
  3. StringUtils.isNoneBlank(null,null) =false
  4. StringUtils.isNoneBlank("","bar") =false
  5. StringUtils.isNoneBlank("bob","") =false
  6. StringUtils.isNoneBlank("bob ",null) =false
  7. StringUtils.isNoneBlank(" ","bar") =false
  8. StringUtils.isNoneBlank("foo","bar") =true
  1. /** 
  2.  * <p>Checks if none of the CharSequences are blank ("") or null and whitespace only..</p> 
  3.  * @paramcss the CharSequences to check, may be null or empty 
  4.  * @return{@codetrue} if none of the CharSequences are blank or null or whitespace only 
  5.  * @since3.2 
  6.  */
  7. publicstaticbooleanisNoneBlank(finalCharSequence... css){
  8.     return!isAnyBlank(css);
  9. }

StringUtils的其他方法

可以参考官方的文档,里面有详细的描述,有些方法还是很好用的.
https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html