result: "yoyo":"hogehoge","num":25,"flg":false,"listMember":["hoge","fuga","derodero"],"listmember2":[{"serviceUrl":"yoyoyousei","message":"genki","imageUrl":"url","version":100},{"serviceUrl":"yoyoyousei","message":"genki","imageUrl":"url","version":100}]}

1jacksontest.java

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by souichi_sumi on 2017/06/19.
 */
public class Main {

    public static void main(String args[]) throws JsonProcessingException{
        System.out.println("こんにちは");
        System.out.println("jacksonのテストをします");
        Target taa = new Target();

        taa.getListMember().add("hoge");
        taa.getListMember().add("fuga");
        taa.getListMember().add("derodero");

        InnerTarget inner =new InnerTarget();

        taa.listmember2.add(inner);
        taa.listmember2.add(inner);

        ObjectMapper om = new ObjectMapper();

        String json = om.writeValueAsString(taa);
        System.out.println(json);
    }
}

innertarget.java

/**
 * Created by souichi_sumi on 2017/06/19.
 */
public class InnerTarget {
    private String serviceUrl = "yoyoyousei";

    private String message = "genki";

    private String imageUrl = "url";

    private Integer version = 100;

    public String getServiceUrl() {
        return serviceUrl;
    }

    public void setServiceUrl(String serviceUrl) {
        this.serviceUrl = serviceUrl;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }

    public Integer getVersion() {
        return version;
    }

    public void setVersion(Integer version) {
        this.version = version;
    }

    public InnerTarget() {

    }

    public InnerTarget(String serviceUrl, String message, String imageUrl, Integer version) {

        this.serviceUrl = serviceUrl;
        this.message = message;
        this.imageUrl = imageUrl;
        this.version = version;
    }
}

target.java

import java.util.ArrayList;
import java.util.List;

/**
 * Created by souichi_sumi on 2017/06/19.
 */
public class Target {
    public String yoyo = "hogehoge";
    public Integer num = 25;
    public Boolean flg = false;
    private List<String> listMember = new ArrayList<String>();
    protected List<InnerTarget> listmember2=new ArrayList<InnerTarget>();
    public String getYoyo() {
        return yoyo;
    }

    public List<InnerTarget> getListmember2() {
        return listmember2;
    }

    public void setListmember2(List<InnerTarget> listmember2) {
        this.listmember2 = listmember2;
    }

    public void setYoyo(String yoyo) {
        this.yoyo = yoyo;
    }

    public Integer getNum() {
        return num;
    }

    public void setNum(Integer num) {
        this.num = num;
    }

    public Boolean getFlg() {
        return flg;
    }

    public void setFlg(Boolean flg) {
        this.flg = flg;
    }

    public List<String> getListMember() {
        return listMember;
    }

    public void setListMember(List<String> listMember) {
        this.listMember = listMember;
    }

    public Target() {

    }
}