如何使用 Java 中的 Exclude Filter 将 bean 转换为 JSON 对象?
javajsonobject oriented programmingprogramming
JsonConfig 类可用于配置序列化过程。我们可以使用 JsonConfig 的 setJsonPropertyFilter() 方法在序列化为 JSON 时设置属性过滤器。我们需要通过重写 PropertyFilter 接口的 apply() 方法来实现 custom PropertyFilter 类。如果属性将被过滤掉，则返回 true，否则返回 false。
语法
public void setJsonPropertyFilter(PropertyFilter jsonPropertyFilter)
示例
import net.sf.json.JSONObject;
import net.sf.json.JsonConfig;
import net.sf.json.util.PropertyFilter;
public class ConvertBeanToJsonExcludeFilterTest {
public static void main(String[] args) {
Student student = new Student("Sai", "Chaitanya", 20, "Hyderabad");
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.setJsonPropertyFilter(new CustomPropertyFilter());
JSONObject jsonObj = JSONObject.fromObject(student, jsonConfig);
System.out.println(jsonObj.toString(3)); //pretty print JSON
}
public static class Student {
private String firstName, lastName, address;
public int age;
public Student(String firstName, String lastName, int age, String address) {
super();
this.firstName = firstName;
this.lastName = lastName;
this.age = age;
this.address = address;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public int getAge() {
return age;
}
public String getAddress() {
return address;
}
}
}
// CustomPropertyFilter class
class CustomPropertyFilter implements PropertyFilter {
@Override
public boolean apply(Object source, String name, Object value) {
if(Number.class.isAssignableFrom(value.getClass()) || String.class.isAssignableFrom(value.getClass())) {
return false;
}
return true;
}
}
输出
{
"firstName": "Sai",
"lastName": "Chaitanya",
"address": "Hyderabad",
"age": 20
}
