如何使用Java中的排除过滤器将bean转换为JSON对象？
该JsonConfig 类可用于配置序列化进程。我们可以使用setJsonPropertyFilter()的方法JsonConfig 序列化到JSON时设置属性过滤器。我们需要通过重写PropertyFilter 接口的apply()方法来实现自定义 PropertyFilter 类。如果将滤除该属性，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类
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;
}
}输出结果
{
"firstName": "Sai",
"lastName": "Chaitanya",
"address": "Hyderabad",
"age": 20
}