I want to set the value in the private field, but it doesn't work.

package test;

import java.lang.reflect.Field;

public classSetCallTest{
    private HasPrivate hasPrivate;
    private Nakaminakami;

    public static void main(String[]args) {
        SetCallTest = newSetCallTest();
        System.out.println("Set Nakami".");
        test.setNakami();
        System.out.println("Retrieves the set Nakami.");
        test.getNakami();
        System.out.println("Retrieve the original Nakami.");
        test.getArimasu();
    }

    publicSetCallTest(){
        hasPrivate = new HasPrivate();
        Nakami=new Nakami();
    }

    public void setNakami(){
        try{
            Field privateField=HasPrivate.class.getDeclaredField("nakami");
            privateField.setAccessible(true);
            privateField.set(hasPrivate,nakami);
        } catch(NoSuchFieldException | SecurityException){
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch(IllegalArgumentExceptione){
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch(IllegalAccessExceptione){
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch(NullPointerExceptione){
            e.printStackTrace();
        }
    }

    public void getNakami(){
        try{
            Field privateField=HasPrivate.class.getDeclaredField("nakami");
            privateField.setAccessible(true);
            Nakaminakami2=(Nakami)privateField.get(hasPrivate);
            System.out.println("Retrieved Nakami:"+nakami2);
            System.out.println("Nakami:" + hasPrivate.getNakami());
            System.out.println("Nakami's nakami:"+nakami2.nakami);
        } catch(Exceptione){
            e.printStackTrace();
        }
    }

    public void getArimasu() {
        try{
            Field arimasu=HasPrivate.class.getDeclaredField("arimasu");
            arimasu.setAccessible(true);
            Nakaminakami2=(Nakami)arimasu.get(hasPrivate);
            System.out.println("Retrieved arimasu:"+nakami2);
            System.out.println("ariamsu:" + hasPrivate.getArimasu());
            System.out.println("arimasu no nakami:"+nakami2.nakami);
        } catch(Exceptione){
            e.printStackTrace();
        }
    }
}

package test;

public class HasPrivate {
    private Nakaminakami;
    private Nakami arimasu=new Nakami();

    public Nakami getNakami(){
        return nakami;
    }

    public NakamigetArimasu(){
        return arimasu;
    }
}

package test;

public class Nakami {
    public String Nakami="Contents";
}

package com.example.sakaguchi.test.all.model;

import android.support.test.runner.AndroidJUnit4;
import android.test.suitebuilder.annotation.LargeTest;

import org.json.JSONException;
import org.json.JSONObject;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import java.lang.reflect.Method;
import java.util.ArrayList;

import com.example.sakaguchi.model.PriceItem;
import com.example.sakaguchi.model.PriceListDataLoader;
import com.example.sakaguchi.model.PriceListData;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;

/**
 * PhotoListData testing.
 * A dummy json is passed to test whether data can be acquired accordingly.
 * Currently, the following three patterns are available.
 * ·Group photo
 * ·Snap photographs, data sales available, development sales available
 * ·Session expired
 */
@LargeTest
@RunWith (AndroidJUnit4.class)
public class PriceListDataLoaderTest{
    PriceListDataLoader mPriceListDataLoader;
    PriceListDataPriceListData;
    JSONObject mPriceListJson, mSessionOutJson;

    @Before
    public void setUp(){
        mPriceListData=newPriceListDataLoader();

        mPriceListData = newPriceListData();
        Field priceListData=HasPrivate.class.getDeclaredField("mPriceListData");
    priceListData.setAccessible(true);
    priceListData.set(mPriceListDataLoader, mPriceListData);

        try{
            // Create json
        } catch(JSONExceptione){
            e.printStackTrace();
        }
    }

    /* The test method follows.
    * Invoke this private method of mPriceListDataLoader.
    * In the method, data obtained and processed from the argument json is put into PriceListData.
    * I would like to check the PriceListData to see if it contains the expected data.
    * However, it should have been set to mPriceListDataLoader in the first place.
    * mPriceListData is said to be null */
}