Android 如何发送多个Json请求并用数据填充ReyclView

我正在练习为wordpress博客构建一个android应用程序，我基本上想做的是展示文章标题和作者。我能够毫不费力地获取和显示文章标题，但让人头痛的是文章作者

这是json的链接

这是我的密码

positems

public class PostItems implements Parcelable {
    private String post_title;
    private String post_author;

    public String getPost_title() {
        return post_title;
    }

    public void setPost_title(String post_title) {
        this.post_title = post_title;
    }



    public String getPost_author() {
        return post_author;
    }

    public void setPost_author(String post_author) {
        this.post_author = post_author;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.post_title);
        dest.writeString(this.post_author);
    }

    public PostItems() {
    }

    protected PostItems(Parcel in) {
        this.post_title = in.readString();
        this.post_author = in.readString();
    }

    public static final Parcelable.Creator<PostItems> CREATOR = new Parcelable.Creator<PostItems>() {
        @Override
        public PostItems createFromParcel(Parcel source) {
            return new PostItems(source);
        }

        @Override
        public PostItems[] newArray(int size) {
            return new PostItems[size];
        }
    };
}

public类positems实现可包裹{
私有字符串post_title；
私有字符串post_作者；
公共字符串getPost_title（）{
返回帖子标题；
}
公共void setPost_title（字符串post_title）{
this.post\u title=post\u title；
}
公共字符串getPost_author（）{
回邮作者；
}
public void setPost_author（字符串post_author）{
this.post_author=post_author；
}
@凌驾
公共int描述内容（）{
返回0；
}
@凌驾
公共无效写入包裹（包裹目的地，内部标志）{
目的地书面记录（此邮政标题）；
目的地写作网（本帖作者）；
}
公共职位（）{
}
受保护邮件项（包裹中）{
this.post_title=in.readString（）；
this.post_author=in.readString（）；
}
public static final Parcelable.Creator=新建Parcelable.Creator（）{
@凌驾
公共PostItems createFromParcel（地块源）{
返回新帖子（来源）；
}
@凌驾
public PostItems[]新数组（整数大小）{
返回新的positem[大小]；
}
};
}

帖子列表的一部分

...
private void getData(){
         Log.d(TAG, "getData called");
         final ProDialoFrag dialoFrag = ProDialoFrag.newInstance();
         dialoFrag.show(getFragmentManager(), "fragmentDialog");


         //Creating a json request
         jsonArrayRequest = new JsonArrayRequest(GET_URL,
                 new Response.Listener<JSONArray>() {
                     @Override
                     public void onResponse(JSONArray response) {
                         Log.d(TAG, "onResponse called");
                         //Dismissing the progress dialog
                         if (dialoFrag != null ) {
                             dialoFrag.dismiss();
                         }
                         //calling method to parse json array
                         parseData(response);

                     }
                 },
                 new Response.ErrorListener() {
                     @Override
                     public void onErrorResponse(VolleyError error) {
                         if (dialoFrag != null) {
                             dialoFrag.dismiss();
                         }
                         if (sthWrongAlert != null) {
                             sthWrongAlert.show();
                         }

                     }
                 }) {

         };

         //Creating request queue
         RequestQueue requestQueue = Volley.newRequestQueue(getActivity());

         //Adding request to the queue
         requestQueue.add(jsonArrayRequest);

     }

     //This method will parse json data
     private void parseData(JSONArray array){
         Log.d(TAG, "Parsing array");

         mPostItemsList.clear();


         for(int i = 0; i<array.length(); i++) {
             PostItems postItem = new PostItems();
             JSONObject jsonObject = null;
             try {
                 jsonObject = array.getJSONObject(i);

                 JSONObject postTitle = jsonObject.getJSONObject("title");
                 postItem.setPost_title(postTitle.getString("rendered"));

                 JSONObject links = jsonObject.getJSONObject("_links");
                 JSONArray authorLink = links.getJSONArray("author");
                 String authorhref = authorLink.getJSONObject(0).getString("name")



                 postItem.setPostId(jsonObject.getString("link"));
             } catch (JSONException w) {
                 w.printStackTrace();
                 //Toast.makeText(this, "Error in parsing Json", Toast.LENGTH_LONG).show();
             }

             mPostItemsList.add(postItem);

         }
         adapter.notifyItemRangeChanged(0, adapter.getItemCount());


     }

public class PostFragment extends Fragment{

    private List<PostItems> mPostItemsList = new ArrayList<>();
    ...
    // Nothing changed here, just added it so you will understand my code better
    ObservableRecyclerView recyclerView;
        private RecyclerView.Adapter adapter;
        LinearLayoutManager mLayoutManager;


        public PostFragment() {
            // Required empty public constructor
        }


        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            String title = getArguments().getString("title");
            // Inflate the layout for this fragment
            view = inflater.inflate(R.layout.fragment_post, container, false);
            //Initializing Views
            recyclerView = (ObservableRecyclerView) view.findViewById(R.id.post_recycler);
            recyclerView.setScrollViewCallbacks(this);
            mLayoutManager = new LinearLayoutManager(getActivity());
            recyclerView.setLayoutManager( mLayoutManager);
            ...

    //This method will get data from the web api
        private void getData(){
            Log.d(TAG, "getData called");
            final ProDialoFrag dialoFrag = ProDialoFrag.newInstance();
            dialoFrag.show(getFragmentManager(), "fragmentDialog");


            //Creating a json request
            jsonArrayRequest = new JsonArrayRequest(GET_URL,
                    new Response.Listener<JSONArray>() {
                        @Override
                        public void onResponse(JSONArray response) {
                            Log.d(TAG, "onResponse called");
                            //Dismissing the progress dialog
                            if (dialoFrag == null ) {
                                dialoFrag.dismiss();
                            }
                            //calling method to parse json array
                            parseData(response);

                        }
                    },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            if (dialoFrag != null) {
                                dialoFrag.dismiss();
                            }
                            if (sthWrongAlert != null) {
                                sthWrongAlert.show();
                            }

                        }
                    }) {
                n Response.success(resp.result, entry);
                }
            };

            //Creating request queue
            RequestQueue requestQueue = Volley.newRequestQueue(getActivity());

            //Adding request to the queue
            requestQueue.add(jsonArrayRequest);

        }

        //This method will parse json data
        private void parseData(JSONArray array){
            Log.d(TAG, "Parsing array");

            for(int i = 0; i<array.length(); i++) {

                JSONObject jsonObject;
                try {
                    jsonObject = array.getJSONObject(i);

                    JSONObject postTitle = jsonObject.getJSONObject("title");
                    String title = postTitle.getString("rendered"));

                    JSONObject links = jsonObject.getJSONObject("_links");
                    JSONArray authorLink = links.getJSONArray("author");
                    String authorhref = authorLink.getJSONObject(0).getString("href");

                    PostItems postItem = new PostItems();
                    postItem.setPost_title(title);
                    postItem.setPostAuthorUrl(authorhref);
                    mPostItemsList.add(postItem);

                    if (adapter.getAuthor(authorhref) == null) {
                        getAuthor(authorhref);
                    }
                } catch (JSONException w) {
                    w.printStackTrace();
                    //Toast.makeText(this, "Error in parsing Json", Toast.LENGTH_LONG).show();
                }



            }
            adapter.setPostItems(mPostItemsList);


        }

        private void getAuthor (String authorhref) {
            Log.d(TAG, "getAuthor called");

            JsonObjectRequest authorRequest = new JsonObjectRequest(authorhref, null,
                    new Response.Listener<JSONObject>() {
                        @Override
                        public void onResponse(JSONObject response) {
                            Log.d(TAG, "onResponse called");
                            parseAuthor(response);
                        }
                    },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            //Do nothing
                        }
                    });
            authorRequest.setShouldCache(false);
            RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
            requestQueue.add(authorRequest);
        }
        private void parseAuthor (JSONObject object) {
            Log.d(TAG, "Parsing auhor");
            try {
                JSONObject links = object.getJSONObject("_links");
                JSONArray self = links.getJSONArray("self");
                String href = self.getJSONObject(0).getString("href");

                String authorname = object.getString("name");
                adapter.putAuthor(href, authorname);
            } catch (JSONException w) {
                w.printStackTrace();
            }
        }

}

。。。
私有void getData（）{
Log.d（标记“getData called”）；
final ProDialoFrag dialoFrag=ProDialoFrag.newInstance（）；
show（getFragmentManager（），“fragmentDialog”）；
//创建json请求
jsonArrayRequest=新的jsonArrayRequest（获取URL，
新的Response.Listener（）{
@凌驾
公共void onResponse（JSONArray响应）{
Log.d（标记“onResponse called”）；
//取消“进度”对话框
如果（dialoFrag！=null）{
dialoFrag.disclose（）；
}
//调用方法来解析json数组
解析数据（响应）；
}
},
新的Response.ErrorListener（）{
@凌驾
公共无效onErrorResponse（截击错误）{
如果（dialoFrag！=null）{
dialoFrag.disclose（）；
}
如果（sthWrongAlert！=null）{
sthWrongAlert.show（）；
}
}
}) {
};
//创建请求队列
RequestQueue RequestQueue=Volley.newRequestQueue（getActivity（））；
//将请求添加到队列
add（jsonArrayRequest）；
}
//此方法将解析json数据
私有void parseData（JSONArray数组）{
d（标记，“解析数组”）；
mPostItemsList.clear（）；
对于（int i=0；i如果您使用的是
HttpURLConnection
和
AsyncTask
，则可以在一个后台操作中发出这两个请求，并且没有问题

但是，由于您似乎致力于使用截击，我建议您使用两个阶段的方法。在第1阶段，您解析帖子并保存帖子的作者url。在第2阶段，您将作者名称添加到按url索引的映射中


让
positem
包含作者url而不是作者姓名：

public class PostItem implements Parcelable {
    private String post_title;
    private String post_author_url;
    // also change all the getters/setters/parceling etc.
}

（我把它做成PostItem——单数形式——因为它不是任何类型的同质集合。）

将
映射添加到适配器以包含作者姓名：

    /** posts, which contain author url */
    private List<PostItem> mPostItems;

    /** authors by url */
    private Map<String, String> mAuthorMap;



请注意，我将您的
getAuthor
方法更改为获取参数（而不是使用成员变量）：


收到作者后，将其添加到适配器

        private void parseAuthor (JSONObject object) {

            Log.d(TAG, "Parsing author");
            try {
                JSONObject links = jsonObject.getJSONObject("_links");
                JSONArray self = links.getJSONArray("self");
                String href = authorLink.getJSONObject(0).getString("href");

                String authorname = object.getString("name");
                mAdapter.putAuthor(href, name);

            } catch (JSONException w) {
                w.printStackTrace();
            }

       }


下面是新的适配器方法：

    public void setPostItems(List<PostItem> postItems) {
        mPostItems = postItems;
        notifyDataSetChanged();
    }

    public void putAuthor(String url, String name) {
        mAuthorMap.put(url, name);
        notifyDataSetChanged();
    }

    public String getAuthor(String url) {
        return mAuthorMap.get(url);
    }




编辑：获取作者url的不同方式，无需解析作者JSON->\u links->self[0]->href

        // notice that authorhref is final
        private void getAuthor (final String authorhref) {
            Log.d(TAG, "getAuthor called");

            JsonObjectRequest authorRequest = new JsonObjectRequest(authorhref, null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d(TAG, "onResponse called");
                        parseAuthor(authorhref, response);  // pass authorhref with response
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        //Do nothing
                    }
                });
                authorRequest.setShouldCache(false);
                RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
                requestQueue.add(authorRequest);
            }

            private void parseAuthor (String authorhref, JSONObject object) {

                Log.d(TAG, "Parsing author");
                try {
                    String authorname = object.getString("name");
                    mAdapter.putAuthor(authorhref, name);

                } catch (JSONException w) {
                    w.printStackTrace();
                }

            }

//注意authorhref是final
私有void getAuthor（最终字符串authorhref）{
Log.d（标记“getAuthor called”）；
JsonObjectRequest authorRequest=新的JsonObjectRequest（authorhref，null，
新的Response.Listener（）{
@凌驾
公共void onResponse（JSONObject响应）{
Log.d（标记“onResponse called”）；
parseAuthor（authorhref，response）；//传递authorhref和response
}
},
新的Response.ErrorListener（）{
@凌驾
公共无效onErrorResponse（截击错误）{
//无所事事
}
});
authorRequest.setShouldCache（false）；
RequestQueue RequestQueue=Volley.newRequestQueue（getActivity（））；
添加（authorRequest）；
}
私有void parseAuthor（字符串authorhref，JSONObject对象）{
Log.d（标记“解析作者”）；
试一试{
字符串authorname=object.getString（“名称”）；
mAdapter.putAuthor（authorhref，名称）；
}捕获（JSONException w）{
w、 printStackTrace（）；
}
}
谢谢！我真的很感谢你的回答。我已经更新了我的问题，以反映应用你的答案后所做的更改以及我遇到的问题。请看一看。我为什么
public PostAdapter(List<PostItems> postItems, Context context) {
    super();

    //Getting all posts
    this.mPostItems = postItems;
    this.mContext = context;
    this.mAuthorMap = new HashMap<>();
}

    private void parseData(JSONArray array){

        Log.d(TAG, "Parsing array");

        // Collect all the PostItems and add to adapter all at once
        List<PostItem> postItems = new ArrayList<>();

        for (int i = 0; i<array.length(); i++) {
            JSONObject jsonObject;
            try {
                jsonObject = array.getJSONObject(i);

                JSONObject postTitle = jsonObject.getJSONObject("title");
                String title = postTitle.getString("rendered");

                JSONObject links = jsonObject.getJSONObject("_links");
                JSONArray authorLink = links.getJSONArray("author");
                String authorhref = authorLink.getJSONObject(0).getString("href");

                PostItem postItem = new PostItem();
                postItem.setPostTitle(title);
                postItem.setPostAuthorUrl(authorhref);
                postItems.add(postItem);

                if (mAdapter.getAuthor(authorhref) == null) {
                    getAuthor(authorhref);
                }

            } catch (JSONException w) {
                w.printStackTrace();
                //Toast.makeText(this, "Error in parsing Json", Toast.LENGTH_LONG).show();
            }
        }

        mAdapter.setPostItems(postItems);
    }

        private void getAuthor(String authorhref) {
            ...

        private void parseAuthor (JSONObject object) {

            Log.d(TAG, "Parsing author");
            try {
                JSONObject links = jsonObject.getJSONObject("_links");
                JSONArray self = links.getJSONArray("self");
                String href = authorLink.getJSONObject(0).getString("href");

                String authorname = object.getString("name");
                mAdapter.putAuthor(href, name);

            } catch (JSONException w) {
                w.printStackTrace();
            }

       }

    public void setPostItems(List<PostItem> postItems) {
        mPostItems = postItems;
        notifyDataSetChanged();
    }

    public void putAuthor(String url, String name) {
        mAuthorMap.put(url, name);
        notifyDataSetChanged();
    }

    public String getAuthor(String url) {
        return mAuthorMap.get(url);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        if (holder instanceof CardDetails) {
            final PostItem postItem = mPostItems.get(position);
            ((CardDetails) holder).postTitle.setText(Html.fromHtml(postItem.getPostTitle()));

            String name = mAuthorMap.get(postItem.getPostAuthorUrl());

            if (name != null) {
                ((CardDetails) holder).postAuthor.setText(name);
            }
            // don't worry if author name is null, when it's retrieved
            // the adapter will be notified to refresh the list

        } else {
            ((ProgressViewHolder)  holder).progressBar.setIndeterminate(true);
        }
    }

        // notice that authorhref is final
        private void getAuthor (final String authorhref) {
            Log.d(TAG, "getAuthor called");

            JsonObjectRequest authorRequest = new JsonObjectRequest(authorhref, null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d(TAG, "onResponse called");
                        parseAuthor(authorhref, response);  // pass authorhref with response
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        //Do nothing
                    }
                });
                authorRequest.setShouldCache(false);
                RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
                requestQueue.add(authorRequest);
            }

            private void parseAuthor (String authorhref, JSONObject object) {

                Log.d(TAG, "Parsing author");
                try {
                    String authorname = object.getString("name");
                    mAdapter.putAuthor(authorhref, name);

                } catch (JSONException w) {
                    w.printStackTrace();
                }

            }