NotNull、NotEmpty、NotBlank 的区别

@NotNull

The CharSequence, Collection, Map or Array object is not null, but can be empty.

@NotEmpty

The CharSequence, Collection, Map or Array object is not null and size > 0.

@NotBlank

The string is not null and the trimmed length is greater than zero.

Here are a few examples:

String name = null;
	@NotNull: false
	@NotEmpty: false
	@NotBlank: false
String name = "";
	@NotNull: true
	@NotEmpty: false
	@NotBlank: false
String name = " ";
	@NotNull: true
	@NotEmpty: true
	@NotBlank: false
String name = "Great answer!";
	@NotNull: true
	@NotEmpty: true
	@NotBlank: true