Java 使用Gson返回空值的嵌套Json

我正在从事的项目是尝试与FDA API进行通信并检索某些信息。但是，对于嵌套的JSON，我试图检索的对象返回一个

null

值。有人知道我做错了什么吗？谢谢，如果我遗漏了任何信息，请告诉我

我试图从中访问信息的URL:
?

JSON测试仪类

package com.example.user.searchbarapp;

import java.net.*;
import java.io.*;
import com.google.gson.*;

public class JSONTester {    
    public static void main(String[] args) throws Exception {
        Gson g = new Gson();
        URL FDAServer = new URL("https://api.fda.gov/drug/label.json?");
        HttpURLConnection conn = (HttpURLConnection)
        FDAServer.openConnection();
        conn.setRequestProperty("User-Agent", "Mozilla/5.0");
        InputStreamReader inputStream = new InputStreamReader(conn.getInputStream(), "UTF-8");
        Medication advil = g.fromJson(inputStream, Medication.class);
        System.out.print(advil);
    }
}

package com.example.user.searchbarapp;

import java.net.URL;
import java.util.Arrays;

public class Medication {

    private NestedMedication[] NestedMedication;

    public Medication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    public com.example.user.searchbarapp.NestedMedication[] getNestedMedication() {
        return NestedMedication;
    }

    public void setNestedMedication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    @Override
    public String toString() {
        return "Medication{" +
                "NestedMedication=" + Arrays.toString(NestedMedication) +
                '}';
    }
}

package com.example.user.searchbarapp;

public class NestedMedication {

    String route;

    @Override
    public String toString() {
        return "NestedMedication{" +
                "route='" + route + '\'' +
                '}';
    }
}

药物类

package com.example.user.searchbarapp;

import java.net.*;
import java.io.*;
import com.google.gson.*;

public class JSONTester {    
    public static void main(String[] args) throws Exception {
        Gson g = new Gson();
        URL FDAServer = new URL("https://api.fda.gov/drug/label.json?");
        HttpURLConnection conn = (HttpURLConnection)
        FDAServer.openConnection();
        conn.setRequestProperty("User-Agent", "Mozilla/5.0");
        InputStreamReader inputStream = new InputStreamReader(conn.getInputStream(), "UTF-8");
        Medication advil = g.fromJson(inputStream, Medication.class);
        System.out.print(advil);
    }
}

package com.example.user.searchbarapp;

import java.net.URL;
import java.util.Arrays;

public class Medication {

    private NestedMedication[] NestedMedication;

    public Medication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    public com.example.user.searchbarapp.NestedMedication[] getNestedMedication() {
        return NestedMedication;
    }

    public void setNestedMedication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    @Override
    public String toString() {
        return "Medication{" +
                "NestedMedication=" + Arrays.toString(NestedMedication) +
                '}';
    }
}

package com.example.user.searchbarapp;

public class NestedMedication {

    String route;

    @Override
    public String toString() {
        return "NestedMedication{" +
                "route='" + route + '\'' +
                '}';
    }
}

嵌套医疗类

package com.example.user.searchbarapp;

import java.net.*;
import java.io.*;
import com.google.gson.*;

public class JSONTester {    
    public static void main(String[] args) throws Exception {
        Gson g = new Gson();
        URL FDAServer = new URL("https://api.fda.gov/drug/label.json?");
        HttpURLConnection conn = (HttpURLConnection)
        FDAServer.openConnection();
        conn.setRequestProperty("User-Agent", "Mozilla/5.0");
        InputStreamReader inputStream = new InputStreamReader(conn.getInputStream(), "UTF-8");
        Medication advil = g.fromJson(inputStream, Medication.class);
        System.out.print(advil);
    }
}

package com.example.user.searchbarapp;

import java.net.URL;
import java.util.Arrays;

public class Medication {

    private NestedMedication[] NestedMedication;

    public Medication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    public com.example.user.searchbarapp.NestedMedication[] getNestedMedication() {
        return NestedMedication;
    }

    public void setNestedMedication(com.example.user.searchbarapp.NestedMedication[] nestedMedication) {
        NestedMedication = nestedMedication;
    }

    @Override
    public String toString() {
        return "Medication{" +
                "NestedMedication=" + Arrays.toString(NestedMedication) +
                '}';
    }
}

package com.example.user.searchbarapp;

public class NestedMedication {

    String route;

    @Override
    public String toString() {
        return "NestedMedication{" +
                "route='" + route + '\'' +
                '}';
    }
}

输出

Medication{NestedMedication=null}
Process finished with exit code 0

---

您链接的json没有

nestedmediation

节点。你的意思是

结果

？我需要用我试图访问的json节点命名我的类吗？我想如果我在NestedMedical中定义了route，它就会访问它