JSONの使用.

場合によっては、あるオブジェクトをJSON文字列に変換する場合、そのオブジェクトのいくつかの属性をオブジェクトに変換する必要がない場合がありますが、次の方法を使用します.
Pojoオブジェクトを定義する

package com.zf.vo;
import java.sql.Timestamp;
import java.util.Date;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.zf.control.JsonDateFormate;
import com.zf.control.JsonTimestampFormater;

public class Person {
  
	private String name ; 
	
	//     
	@JsonIgnore			
	private int age ;      
	
	//             yyyy-MM-dd hh:mm:ss
	@JsonSerialize(using = JsonTimestampFormater.class)
	private Timestamp birthday ;
	
	//             yyyy-MM-dd 
	@JsonSerialize(using = JsonDateFormate.class)
	private Date updateTime ;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	public Timestamp getBirthday() {
		return birthday;
	}
	      
	public void setBirthday(Timestamp birthday) {
		this.birthday = birthday;
	}
	public Date getUpdateTime() {
		return updateTime;
	}
	public void setUpdateTime(Date updateTime) {
		this.updateTime = updateTime;
	}
	
}

次に、タイプ変換器を定義します.

package com.zf.control;
import java.io.IOException;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
public class JsonTimestampFormater extends JsonSerializer<Timestamp> {
	private final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
	@Override
	public void serialize(Timestamp value, JsonGenerator jgen,
			SerializerProvider sp) throws IOException,
			JsonProcessingException {
		jgen.writeString(sdf.format(value));
	}

}

package com.zf.control;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
public class JsonDateFormate extends JsonSerializer<Date> {
	private final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
	@Override
	public void serialize(Date value, JsonGenerator jgen, SerializerProvider sp)
			throws IOException, JsonProcessingException {
		jgen.writeString(sdf.format(value));
	}
}

再テスト:

public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException, InterruptedException {
		Person person = new Person();
		person.setAge(19);
		person.setName("xxxxx");     
		person.setBirthday(new Timestamp(System.currentTimeMillis()));
		ObjectMapper mapper = new ObjectMapper();      
		String jsonstr = mapper.writeValueAsString(person);
		System.out.println(jsonstr); }

出力結果:
{"name":"xxxxx","birthday":"2012-08-21 03:27:07","updateTime":"2012-08-21"}