对象转Json字符串时如何忽略指定属性

package com.gomefinance.esign;
import com.alibaba.fastjson.annotation.JSONField;
import lombok.Getter;
import lombok.Setter;
import java.io.Serializable;
 
/**
 * 本地签署信息
 * Created by JHAO on 2017/5/31.
 */
@Setter
@Getter
public class FastJsonInputBean implements Serializable {
 
    // 合同模板ID
 
    private String contractTemplateId;
    // 合同号
    private String contractId;
    // Base64编码的合同
    @JSONField(serialize = false)
    private String contractImage;
    private String contractVersion;
 
}

 FastJsonInputBean inputBean = new FastJsonInputBean();
 inputBean.setContractImage("contractImage");
 inputBean.setContractTemplateId("templateId");
 inputBean.setContractId("comtractId");
 inputBean.setContractVersion("contractVersion");
 
 System.out.println("JSONField(serialize = false)忽略contractImage属性:"+JSON.toJSONString(inputBean));

SimplePropertyPreFilter filter = new SimplePropertyPreFilter(FastJsonInputBean.class, "contractTemplateId");
System.out.println("filter忽略contractTemplateId属性:"+JSONObject.toJSONString(inputBean, filter)); 

package com.gomefinance.esign;
import com.alibaba.fastjson.annotation.JSONField;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import lombok.Getter;
import lombok.Setter;
import java.io.Serializable;
 
/**
 * 本地签署信息
 * Created by JHAO on 2017/5/31.
 */
@Setter
@Getter
@JsonIgnoreProperties({"contractTemplateId", "contractImage"})
public class JackSonInputBean implements Serializable {
 
    // 合同模板ID
 
    private String contractTemplateId;
    // 合同号
    @JsonIgnore
    private String contractId;
    // Base64编码的合同
    private String contractImage;
    private String contractVersion;
 
}

 JackSonInputBean jackSonInputBean = new JackSonInputBean();
 jackSonInputBean.setContractImage("contractImage");
 jackSonInputBean.setContractTemplateId("templateId");
 jackSonInputBean.setContractId("comtractId");
 jackSonInputBean.setContractVersion("contractVersion");
 
 ObjectMapper objectMapper = new ObjectMapper();
 System.out.println("JackSon JsonIgnore忽略contractId属性:"+objectMapper.writeValueAsString(jackSonInputBean));