我通过Toast获得异常错误＆＃34; Error..2 JSONException：java.lang.String类型的值无法转换为JSONObject＆＃34;。 请建议一个解决方案！
IT_Faculty.java
package com.roadraz.vcademy1;
import android.app.ListActivity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class IT_Faculty extends AppCompatActivity {
private String jsonResult;
private String url = "<have added my server address>";
private ListView listView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_it__faculty);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
listView = (ListView) findViewById(R.id.faculty_listView);
accessWebService();
}
private class JsonReadTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... params) {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
try {
HttpResponse response = httpclient.execute(httppost);
jsonResult = inputStreamToString(response.getEntity().getContent()).toString();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private StringBuilder inputStreamToString(InputStream is) {
String rLine = "";
StringBuilder answer = new StringBuilder();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
try {
while ((rLine = rd.readLine()) != null) {
answer.append(rLine);
}
} catch (IOException e) {
//e.printStackTrace();
Toast.makeText(IT_Faculty.this, "Error...1" + e.toString(), Toast.LENGTH_LONG).show();
}
return answer;
}
@Override
protected void onPostExecute(String s) {
ListDrawer();
}
}//end async task
public void accessWebService() {
JsonReadTask task = new JsonReadTask();
task.execute(new String[]{url});
}
//build hash set for list view
public void ListDrawer() {
List<Map<String, String>> facultyList = new ArrayList<Map<String, String>>();
try {
JSONObject jsonResponse = new JSONObject(jsonResult);
JSONArray jsonMainNode = jsonResponse.optJSONArray("asdb");
for (int i = 0; i < jsonMainNode.length(); i++) {
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
String name = jsonChildNode.optString("name");
String number = jsonChildNode.optString("roll_no");
String outPut = name + "-" + number;
facultyList.add(createFaculty("faculties",outPut));
}
} catch (JSONException e) {
Toast.makeText(IT_Faculty.this, "Error...2" + e.toString(), Toast.LENGTH_LONG).show();
}
SimpleAdapter simpleAdapter= new SimpleAdapter(IT_Faculty.this,facultyList,
android.R.layout.simple_list_item_1,new String[]{"faculties"},new int[]{android.R.id.text1});
listView.setAdapter(simpleAdapter);
Toast.makeText(IT_Faculty.this, "c", Toast.LENGTH_SHORT).show();
}
private HashMap<String,String> createFaculty(String name,String roll_no){
HashMap<String,String> facultyNameNo=new HashMap<String,String>();
facultyNameNo.put(name,roll_no);
return facultyNameNo;
}
}
it__faculty.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:orientation="vertical"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/activity_it__faculty" tools:context="com.roadraz.vcademy1.IT_Faculty">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/faculty_listView">
</ListView>
</LinearLayout>
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.roadraz.vcademy1" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme" >
<activity
android:name=".FirstPage"
android:label="V-Cademy"
android:theme="@style/AppTheme.NoActionBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".IT_Faculty"
android:label="@string/title_activity_it__faculty"
android:theme="@style/AppTheme.NoActionBar" >
</activity>
</application>
</manifest>
faculty_fetch.php
<?php
$host="localhost";
$username="myusername";
$password="mypassword";
$db_name="asdb";
$con=mysql_connect("$host","$username","$password");
mysql_select_db=("$db_name");
$sql="select * from asdb where class='Faculty'";
$result=mysql_query($sql);
$json=array();
if(mysql_num_rows($result)){
while($row=mysql_fetch_assoc($result)){
$json['asdb']['sr_no']=$row['sr_no']
$json['asdb']['name']=$row['name']
$json['asdb']['email']=$row['email']
$json['asdb']['roll_no']=$row['roll_no']
$json['asdb']['class']=$row['class']
$json['asdb']['phone']=$row['phone']
$json['asdb']['password']=$row['password'];
}
}
mysql_close($con);
echo json_encode($json);
?>
这是Android监视器
03-25 01:43:08.802 28804-28804/? I/art: Not late-enabling -Xcheck:jni (already on)
03-25 01:43:08.802 28804-28804/? I/art: Late-enabling JIT
03-25 01:43:08.810 28804-28804/? I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
03-25 01:43:08.922 28804-28804/com.roadraz.vcademy1 W/System: ClassLoader referenced unknown path: /data/app/com.roadraz.vcademy1-1/lib/x86
03-25 01:43:09.445 28804-28811/com.roadraz.vcademy1 W/art: Suspending all threads took: 5.088ms
03-25 01:43:09.839 28804-28837/com.roadraz.vcademy1 D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
03-25 01:43:09.859 28804-28804/com.roadraz.vcademy1 D/: HostConnection::get() New Host Connection established 0xab8027b0, tid 28804
03-25 01:43:10.115 28804-28811/com.roadraz.vcademy1 W/art: Suspending all threads took: 164.743ms
03-25 01:43:10.269 28804-28837/com.roadraz.vcademy1 I/OpenGLRenderer: Initialized EGL, version 1.4
03-25 01:43:10.316 28804-28837/com.roadraz.vcademy1 W/EGL_emulation: eglSurfaceAttrib not implemented
03-25 01:43:10.316 28804-28837/com.roadraz.vcademy1 W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xabfbe100, error=EGL_SUCCESS
03-25 01:43:10.874 28804-28836/com.roadraz.vcademy1 W/MYAPP: org.apache.http.message.BasicHttpResponse@fed3d3f
03-25 01:43:10.875 28804-28836/com.roadraz.vcademy1 W/MYAPP: org.apache.http.message.BasicHttpResponse@fed3d3f
03-25 01:43:11.012 28804-28837/com.roadraz.vcademy1 W/EGL_emulation: eglSurfaceAttrib not implemented
03-25 01:43:11.012 28804-28837/com.roadraz.vcademy1 W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad7b4460, error=EGL_SUCCESS
03-25 01:43:14.417 28804-28837/com.roadraz.vcademy1 E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb4057390
03-25 01:43:14.491 28804-28837/com.roadraz.vcademy1 W/EGL_emulation: eglSurfaceAttrib not implemented
03-25 01:43:14.491 28804-28837/com.roadraz.vcademy1 W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad7cc3a0, error=EGL_SUCCESS
03-25 01:43:16.438 28804-28837/com.roadraz.vcademy1 E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb4053dc0
答案 0 :(得分：0)
尝试将其更改为以下
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