Java中Jackson @ JsonInclude注释的重要性？
Jackson @JsonInclude注解可以用于在特定条件下排除类的属性或字段，并且可以使用JsonInclude定义它。包括枚举。JsonInclude。Include enum包含几个常量，如"ALWAYS"，"NON_DEFAULT"， "NON_EMPTY"和"NON_NULL"，以确定是否排除该属性(字段)。
语法
public static enum JsonInclude.Include extends Enum<JSonInclude.Include>
示例
import com.fasterxml.jackson.annotation.*;
import com.fasterxml.jackson.databind.*;
import java.io.*;
public class JsonIncludeTest {
public static void main(String args[]) throws IOException {
ObjectMapper objectMapper = new ObjectMapper();
Employee emp = new Employee();
String jsonString = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(emp);
System.out.println(jsonString);
}
}
// Employee class
@JsonInclude(JsonInclude.Include.NON_EMPTY)
class Employee {
public int empId = 115;
public String empName = null;
@Override
public String toString() {
return "Employee{" +
"empId=" + empId +
", empName='" + empName + '\'' +
'}';
}
}输出结果
{
"empId" : 115
}