如何在Java（Android Studio）中处理JSON

我是android新手，正在开发android应用程序，我想从URL获取JSON数据：

我有以下代码：

import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.Bundle;
import android.app.Activity;
import android.widget.TextView;

public class SingleContactActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        String url = "http://ana.fm/api/article/256281468161349/";
        TextView title = (TextView) findViewById(R.id.single_article_title);
        TextView desc = (TextView) findViewById(R.id.single_article_desc);


        String str = "";
        HttpResponse response;
        HttpClient myClient = new DefaultHttpClient();
        HttpGet myConnection = new HttpGet(url);

        try {
            response = myClient.execute(myConnection);
            str = EntityUtils.toString(response.getEntity(), "UTF-8");

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }


        try{
            JSONObject parent_obj = new JSONObject(str);
            JSONArray jArray= parent_obj.getJSONArray("article");
            JSONObject json = jArray.getJSONObject(0);


            title.setText(json.getString("title"));
            desc.setText(json.getString("description"));


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

    }


}

这是article.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Article Cover Photo -->
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/single_article_cover_photo"
        android:layout_gravity="center_horizontal" />

    <!-- Article Title -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/single_article_title"
        android:layout_gravity="center_horizontal"
        android:textColor="#acacac" />

    <!-- Article Description -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/single_article_desc"
        android:layout_gravity="center_horizontal" />


</LinearLayout>

我已经在AndroidManifest.xml中设置了internet权限：

<uses-permission android:name="android.permission.INTERNET" />

但当我运行模拟器时，我得到： 无效的 空的

我在代码中找不到任何错误

我用这个代码得到了它：

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;

import java.io.InputStream;


public class SingleContactActivity extends Activity {

    public static String myArticleUrl = "http://ana.fm/api/article/256281468161349/";
    TextView title;
    TextView desc;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        title = (TextView) findViewById(R.id.single_article_title);
        desc = (TextView) findViewById(R.id.single_article_desc);

        new LoadAllArticles().execute();

    }

    // LOADING THE ARTICLE CONTENTS IN THE BACKGROUND
    class LoadAllArticles extends AsyncTask<String, String, Void> {

        private ProgressDialog progressDialog = new ProgressDialog(SingleContactActivity.this);
        InputStream inputStream = null;
        String result = "";
        HttpResponse httpResponse;
        HttpEntity httpEntity;

        protected void onPreExecute() {
            progressDialog.setMessage("Downloading article...");
            progressDialog.show();
            progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface arg0) {
                    LoadAllArticles.this.cancel(true);
                }
            });
        }

        @Override
        protected Void doInBackground(String... params) {

            String url_select = myArticleUrl;

            // Set up HTTP Get
            HttpClient httpClient = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(url_select);

            try {


                httpResponse = httpClient.execute(httpGet);
                result = EntityUtils.toString(httpResponse.getEntity(), "UTF-8");

            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        protected void onPostExecute(Void v) {
            //parse JSON data
            try {

                JSONObject parent_obj = new JSONObject(result);
                JSONArray jArray= parent_obj.getJSONArray("article");
                JSONObject json = jArray.getJSONObject(0);

                title.setText(json.getString("title"));
                desc.setText(json.getString("description"));
                this.progressDialog.dismiss();
            } catch (JSONException e) {
                Log.e("JSONException", "Error: " + e.toString());
            } // catch (JSONException e)
        }
    }
}

import java.io.IOException；
导入org.apache.http.HttpEntity；
导入org.apache.http.HttpResponse；
导入org.apache.http.client.ClientProtocolException；
导入org.apache.http.client.HttpClient；
导入org.apache.http.client.methods.HttpGet；
导入org.apache.http.impl.client.DefaultHttpClient；
导入org.apache.http.util.EntityUtils；
导入org.json.JSONArray；
导入org.json.JSONException；
导入org.json.JSONObject；
导入android.app.ProgressDialog；
导入android.content.DialogInterface；
导入android.os.AsyncTask；
导入android.os.Bundle；
导入android.app.Activity；
导入android.util.Log；
导入android.widget.TextView；
导入java.io.InputStream；
公共类SingleContactActivity扩展了活动{
公共静态字符串myArticleUrl=”http://ana.fm/api/article/256281468161349/";
文本视图标题；
文本视图描述；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.article）；
title=（TextView）findViewById（R.id.single\u article\u title）；
desc=（TextView）findViewById（R.id.single\u article\u desc）；
新建LoadAllArticles（）.execute（）；
}
//在后台加载文章内容
类LoadAllArticles扩展了AsyncTask{
private ProgressDialog ProgressDialog=新建ProgressDialog（SingleContactActivity.this）；
InputStream InputStream=null；
字符串结果=”；
HttpResponse HttpResponse；
HttpEntity HttpEntity；
受保护的void onPreExecute（）{
setMessage（“下载文章…”）；
progressDialog.show（）；
progressDialog.setOnCancelListener（新的DialogInterface.OnCancelListener（）{
public void onCancel（对话框接口arg0）{
LoadAllArticles.this.cancel（true）；
}
});
}
@凌驾
受保护的Void doInBackground（字符串…参数）{
字符串url\u select=myArticleUrl；
//设置HTTP Get
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpGet HttpGet=新的HttpGet（url\u选择）；
试一试{
httpResponse=httpClient.execute（httpGet）；
结果=EntityUtils.toString（httpResponse.getEntity（），“UTF-8”）；
}捕获（客户端协议例外e）{
e、 printStackTrace（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
返回null；
}
受保护的void onPostExecute（void v）{
//解析JSON数据
试一试{
JSONObject父对象=新JSONObject（结果）；
JSONArray jArray=父对象getJSONArray（“文章”）；
JSONObject json=jArray.getJSONObject（0）；
title.setText（json.getString（“title”）；
desc.setText（json.getString（“description”）；
此.progressDialog.discouse（）文件；
}捕获（JSONException e）{
Log.e（“JSONException”，“Error:+e.toString（））；
}//catch（JSONException e）
}
}
}

---

但是现在我需要处理HTML标记，有人知道我如何处理JSON中的HTML标记吗？

编辑：好的，我终于设法进入我的工作PC，所以我纠正了所有错误，现在可以工作了：

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import java.io.InputStream;
import java.util.ArrayList;

public class SingleContactActivity extends Activity {
    String myArticleUrl = "http://ana.fm/api/article/256281468161349/";
    TextView txtTitle;
    TextView txtDesc;
    JSONParser jParser = new JSONParser();
    JSONArray articles = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        txtTitle = (TextView) findViewById(R.id.single_article_title);
        txtDesc = (TextView) findViewById(R.id.single_article_desc);

        new LoadAllArticles().execute();
    }

    // LOADING ALL ARTICLES IN THE BACKGROUND
    class LoadAllArticles extends AsyncTask<String, String, String> {

        private ProgressDialog progressDialog = new ProgressDialog(SingleContactActivity.this);
        InputStream inputStream = null;
        String result = "";
        String title = "";
        String description = "";

        protected void onPreExecute() {
            progressDialog.setMessage("Downloading articles...");
            progressDialog.show();
            progressDialog.setOnCancelListener(new     DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface arg0) {
                    LoadAllArticles.this.cancel(true);
                }
            });
        }

        @Override
        protected String doInBackground(String... params) {

        String url_select = myArticleUrl;

        ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();

        try {
            JSONObject json = jParser.makeHttpRequest(url_select,
                    "GET", param);  // Change "GET" to "POST" if you want the POST method

            articles = json.getJSONArray("article");

            JSONObject jsonObj = articles.getJSONObject(0);

            title = jsonObj.getString("title");
            description = jsonObj.getString("description");

        }
        catch (IllegalStateException e3) {
            Log.e("IllegalStateException", e3.toString());
            e3.printStackTrace();
        }
        catch (JSONException e5) {
            Log.e("JSONException", e5.toString());
            e5.printStackTrace();
        }

        return null;
        }

        @Override
        protected void onPostExecute(String s) {
            try {
                String newTitle = Html.fromHtml(title).toString();
                txtTitle.setText(newTitle);
                String newDesc = Html.fromHtml(description).toString();
                txtDesc.setText(newDesc);
                progressDialog.dismiss();
            } catch (Exception e) {
                Log.e("JSONException", "Error: " + e.toString());
            }
        }

    }
}

---

试试这个，它对我有效，我可以看到一堆阿拉伯语文本…

编辑：好的，我终于设法进入我的工作电脑，所以我纠正了所有错误，现在可以了：

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import java.io.InputStream;
import java.util.ArrayList;

public class SingleContactActivity extends Activity {
    String myArticleUrl = "http://ana.fm/api/article/256281468161349/";
    TextView txtTitle;
    TextView txtDesc;
    JSONParser jParser = new JSONParser();
    JSONArray articles = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        txtTitle = (TextView) findViewById(R.id.single_article_title);
        txtDesc = (TextView) findViewById(R.id.single_article_desc);

        new LoadAllArticles().execute();
    }

    // LOADING ALL ARTICLES IN THE BACKGROUND
    class LoadAllArticles extends AsyncTask<String, String, String> {

        private ProgressDialog progressDialog = new ProgressDialog(SingleContactActivity.this);
        InputStream inputStream = null;
        String result = "";
        String title = "";
        String description = "";

        protected void onPreExecute() {
            progressDialog.setMessage("Downloading articles...");
            progressDialog.show();
            progressDialog.setOnCancelListener(new     DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface arg0) {
                    LoadAllArticles.this.cancel(true);
                }
            });
        }

        @Override
        protected String doInBackground(String... params) {

        String url_select = myArticleUrl;

        ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();

        try {
            JSONObject json = jParser.makeHttpRequest(url_select,
                    "GET", param);  // Change "GET" to "POST" if you want the POST method

            articles = json.getJSONArray("article");

            JSONObject jsonObj = articles.getJSONObject(0);

            title = jsonObj.getString("title");
            description = jsonObj.getString("description");

        }
        catch (IllegalStateException e3) {
            Log.e("IllegalStateException", e3.toString());
            e3.printStackTrace();
        }
        catch (JSONException e5) {
            Log.e("JSONException", e5.toString());
            e5.printStackTrace();
        }

        return null;
        }

        @Override
        protected void onPostExecute(String s) {
            try {
                String newTitle = Html.fromHtml(title).toString();
                txtTitle.setText(newTitle);
                String newDesc = Html.fromHtml(description).toString();
                txtDesc.setText(newDesc);
                progressDialog.dismiss();
            } catch (Exception e) {
                Log.e("JSONException", "Error: " + e.toString());
            }
        }

    }
}

---

试试这个，它对我有效，我可以看到一堆阿拉伯语文本…

编辑：好的，我终于设法进入我的工作电脑，所以我纠正了所有错误，现在可以了：

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import java.io.InputStream;
import java.util.ArrayList;

public class SingleContactActivity extends Activity {
    String myArticleUrl = "http://ana.fm/api/article/256281468161349/";
    TextView txtTitle;
    TextView txtDesc;
    JSONParser jParser = new JSONParser();
    JSONArray articles = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        txtTitle = (TextView) findViewById(R.id.single_article_title);
        txtDesc = (TextView) findViewById(R.id.single_article_desc);

        new LoadAllArticles().execute();
    }

    // LOADING ALL ARTICLES IN THE BACKGROUND
    class LoadAllArticles extends AsyncTask<String, String, String> {

        private ProgressDialog progressDialog = new ProgressDialog(SingleContactActivity.this);
        InputStream inputStream = null;
        String result = "";
        String title = "";
        String description = "";

        protected void onPreExecute() {
            progressDialog.setMessage("Downloading articles...");
            progressDialog.show();
            progressDialog.setOnCancelListener(new     DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface arg0) {
                    LoadAllArticles.this.cancel(true);
                }
            });
        }

        @Override
        protected String doInBackground(String... params) {

        String url_select = myArticleUrl;

        ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();

        try {
            JSONObject json = jParser.makeHttpRequest(url_select,
                    "GET", param);  // Change "GET" to "POST" if you want the POST method

            articles = json.getJSONArray("article");

            JSONObject jsonObj = articles.getJSONObject(0);

            title = jsonObj.getString("title");
            description = jsonObj.getString("description");

        }
        catch (IllegalStateException e3) {
            Log.e("IllegalStateException", e3.toString());
            e3.printStackTrace();
        }
        catch (JSONException e5) {
            Log.e("JSONException", e5.toString());
            e5.printStackTrace();
        }

        return null;
        }

        @Override
        protected void onPostExecute(String s) {
            try {
                String newTitle = Html.fromHtml(title).toString();
                txtTitle.setText(newTitle);
                String newDesc = Html.fromHtml(description).toString();
                txtDesc.setText(newDesc);
                progressDialog.dismiss();
            } catch (Exception e) {
                Log.e("JSONException", "Error: " + e.toString());
            }
        }

    }
}

---

试试这个，它对我有效，我可以看到一堆阿拉伯语文本…

编辑：好的，我终于设法进入我的工作电脑，所以我纠正了所有错误，现在可以了：

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import java.io.InputStream;
import java.util.ArrayList;

public class SingleContactActivity extends Activity {
    String myArticleUrl = "http://ana.fm/api/article/256281468161349/";
    TextView txtTitle;
    TextView txtDesc;
    JSONParser jParser = new JSONParser();
    JSONArray articles = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article);

        txtTitle = (TextView) findViewById(R.id.single_article_title);
        txtDesc = (TextView) findViewById(R.id.single_article_desc);

        new LoadAllArticles().execute();
    }

    // LOADING ALL ARTICLES IN THE BACKGROUND
    class LoadAllArticles extends AsyncTask<String, String, String> {

        private ProgressDialog progressDialog = new ProgressDialog(SingleContactActivity.this);
        InputStream inputStream = null;
        String result = "";
        String title = "";
        String description = "";

        protected void onPreExecute() {
            progressDialog.setMessage("Downloading articles...");
            progressDialog.show();
            progressDialog.setOnCancelListener(new     DialogInterface.OnCancelListener() {
                public void onCancel(DialogInterface arg0) {
                    LoadAllArticles.this.cancel(true);
                }
            });
        }

        @Override
        protected String doInBackground(String... params) {

        String url_select = myArticleUrl;

        ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();

        try {
            JSONObject json = jParser.makeHttpRequest(url_select,
                    "GET", param);  // Change "GET" to "POST" if you want the POST method

            articles = json.getJSONArray("article");

            JSONObject jsonObj = articles.getJSONObject(0);

            title = jsonObj.getString("title");
            description = jsonObj.getString("description");

        }
        catch (IllegalStateException e3) {
            Log.e("IllegalStateException", e3.toString());
            e3.printStackTrace();
        }
        catch (JSONException e5) {
            Log.e("JSONException", e5.toString());
            e5.printStackTrace();
        }

        return null;
        }

        @Override
        protected void onPostExecute(String s) {
            try {
                String newTitle = Html.fromHtml(title).toString();
                txtTitle.setText(newTitle);
                String newDesc = Html.fromHtml(description).toString();
                txtDesc.setText(newDesc);
                progressDialog.dismiss();
            } catch (Exception e) {
                Log.e("JSONException", "Error: " + e.toString());
            }
        }

    }
}

---

试试这个，它对我有用，我可以看到一堆阿拉伯文本…

而不是肛门解析，你可以使用

---

. 您将得到您的发布是java对象。

您可以使用

---

. 您将得到您的发布是java对象。

您可以使用

---

. 您将得到您的发布是java对象。

您可以使用

---

. 您将得到您的发布是java对象。

首先，不要在主线程中执行HTTP请求。您受到NetworkOnMainThread异常的影响。将用于获取JSON数据的代码移动到asynctask。我如何才能做到这一点@ZouZouIt在文档中：-您还可以使用更简单的方法：有几个库专门用于异步网络，例如volley或首先，不要在主线程中执行HTTP请求。您受到NetworkOnMainThread异常的影响。将用于获取JSON数据的代码移动到asynctask。我如何才能做到这一点@ZouZouIt在文档中：-您还可以使用更简单的方法：有几个库专门用于异步网络，例如volley或首先，不要在主线程中执行HTTP请求。您受到NetworkOnMainThread异常的影响。将用于获取JSON数据的代码移动到asynctask。我如何才能做到这一点@ZouZouIt在文档中：-您还可以使用一种更简单的方法：有几个库专门为异步网络而设计，比如volley或首先，不做HTTP请求