如何解决 org.json.JSONException 中的错误？
How to solve error in org.json.JSONException?
我正在创建一个可以通过将 ID 号放入 editText 来检索单词的应用程序。我不断收到此错误。如何解决这个问题呢？ org.json.JSONException：{"server_response" 没有值："Bird"}
这是我的主要内容Activity.java
package com.example.keam.lastnato;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
public class MainActivity extends Activity {
String id;
String word;
InputStream is=null;
String result=null;
String line=null;
String data ="";
TextView disp;
String url = "http://192.168.0.10/checkpls.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText e_id=(EditText) findViewById(R.id.editText1);
Button select=(Button) findViewById(R.id.button1);
disp = (TextView)findViewById(R.id.textView);
select.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
id = e_id.getText().toString();
select();
}
});
}
public void select()
{
class readThis extends AsyncTask<String, Void, String> {
protected String doInBackground(String... params){
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",id));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line);
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
try
{
JSONObject json_data = new JSONObject(result);
word = json_data.getString(result);
Toast.makeText(getBaseContext(), "Name: " + word,
Toast.LENGTH_SHORT).show();
}
catch(JSONException e)
{
Log.e("Fail 3", e.toString());
Log.e("log_tag", "Failed data was: " + result);
}
return word;
}
}
readThis hello = new readThis();
hello.execute(new String[] {url});
}
}
这是我的 activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.keam.lastnato.MainActivity">
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="39dp"
android:padding="11dp"
android:hint="Id"
android:ems="10"
android:inputType="number">
<requestFocus />
</EditText>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginTop="24dp"
android:onClick="parseJSON"
android:padding="11dp"
android:text="Select" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
这是我的 PHP 文件 "checkpls.php"
<?php
$con = mysqli_connect("localhost", "root", "1234", "check") or die ("Error ".mysqli_error($con));
$id = $_POST['id'];
$sql = "SELECT * FROM tblcheckword where id like '$id';";
$result = mysqli_query($con, $sql) or die("Error in selecting ".mysqli_error($con));
$response = array();
if(mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_array($result))
{
array_push($response, array("id"=>$row[0],"word"=>$row[1],"meaning"=>$row[2]));
$retrieve = $row[1];
}
echo json_encode(array("server_response" => $retrieve));
}else{
echo "Retrieve failed";
}
mysqli_close($con);
?>
这是我在 WAMP phpmyadmin 中的 tblcheckword
数据库名称="check"
这是我的 logcat 错误。
08-19 14:10:48.367 23305-23536/com.example.keam.lastnato E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.example.keam.lastnato, PID: 23305
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:200)
at android.os.Handler.<init>(Handler.java:114)
at android.widget.Toast$TN.<init>(Toast.java:372)
at android.widget.Toast.<init>(Toast.java:105)
at android.widget.Toast.makeText(Toast.java:264)
at com.example.keam.lastnato.MainActivityreadThis.doInBackground(MainActivity.java:120)
at com.example.keam.lastnato.MainActivityreadThis.doInBackground(MainActivity.java:61)
at android.os.AsyncTask.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
08-19 14:10:49.969 23305-23536/com.example.keam.lastnato I/Process: Sending signal. PID: 23305 SIG: 9
将word = json_data.getString(result);更改为word = json_data.getString("server_response");
更新：
public void select(){
readThis hello = new readThis();
hello.execute(new String[] {url});
}
private class ReadThis extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... params) {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",id));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line);
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
}
return result ;
}
@Override
protected void onPostExecute(String result) {
try
{
JSONObject json_data = new JSONObject(result);
word = json_data.getString("server_response");
Toast.makeText(getBaseContext(), "Name: " + word,
Toast.LENGTH_SHORT).show();
}
catch(JSONException e)
{
Log.e("Fail 3", e.toString());
Log.e("log_tag", "Failed data was: " + result);
}
}
@Override
protected void onPreExecute() {}
@Override
protected void onProgressUpdate(Void... values) {}
}
JSON 是键值对，例如 {"key","value"};
您要做的是使用 JSON 对象本身获取值。
将行 word = json_data.getString(result); 更改为 word = json_data.getString("YOUR_KEY");
我正在创建一个可以通过将 ID 号放入 editText 来检索单词的应用程序。我不断收到此错误。如何解决这个问题呢？ org.json.JSONException：{"server_response" 没有值："Bird"}
这是我的主要内容Activity.java
package com.example.keam.lastnato;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
public class MainActivity extends Activity {
String id;
String word;
InputStream is=null;
String result=null;
String line=null;
String data ="";
TextView disp;
String url = "http://192.168.0.10/checkpls.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText e_id=(EditText) findViewById(R.id.editText1);
Button select=(Button) findViewById(R.id.button1);
disp = (TextView)findViewById(R.id.textView);
select.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
id = e_id.getText().toString();
select();
}
});
}
public void select()
{
class readThis extends AsyncTask<String, Void, String> {
protected String doInBackground(String... params){
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",id));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line);
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
try
{
JSONObject json_data = new JSONObject(result);
word = json_data.getString(result);
Toast.makeText(getBaseContext(), "Name: " + word,
Toast.LENGTH_SHORT).show();
}
catch(JSONException e)
{
Log.e("Fail 3", e.toString());
Log.e("log_tag", "Failed data was: " + result);
}
return word;
}
}
readThis hello = new readThis();
hello.execute(new String[] {url});
}
}
这是我的 activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.keam.lastnato.MainActivity">
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="39dp"
android:padding="11dp"
android:hint="Id"
android:ems="10"
android:inputType="number">
<requestFocus />
</EditText>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginTop="24dp"
android:onClick="parseJSON"
android:padding="11dp"
android:text="Select" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
这是我的 PHP 文件 "checkpls.php"
<?php
$con = mysqli_connect("localhost", "root", "1234", "check") or die ("Error ".mysqli_error($con));
$id = $_POST['id'];
$sql = "SELECT * FROM tblcheckword where id like '$id';";
$result = mysqli_query($con, $sql) or die("Error in selecting ".mysqli_error($con));
$response = array();
if(mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_array($result))
{
array_push($response, array("id"=>$row[0],"word"=>$row[1],"meaning"=>$row[2]));
$retrieve = $row[1];
}
echo json_encode(array("server_response" => $retrieve));
}else{
echo "Retrieve failed";
}
mysqli_close($con);
?>
这是我在 WAMP phpmyadmin 中的 tblcheckword
数据库名称="check"
这是我的 logcat 错误。
08-19 14:10:48.367 23305-23536/com.example.keam.lastnato E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.example.keam.lastnato, PID: 23305
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:200)
at android.os.Handler.<init>(Handler.java:114)
at android.widget.Toast$TN.<init>(Toast.java:372)
at android.widget.Toast.<init>(Toast.java:105)
at android.widget.Toast.makeText(Toast.java:264)
at com.example.keam.lastnato.MainActivityreadThis.doInBackground(MainActivity.java:120)
at com.example.keam.lastnato.MainActivityreadThis.doInBackground(MainActivity.java:61)
at android.os.AsyncTask.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
08-19 14:10:49.969 23305-23536/com.example.keam.lastnato I/Process: Sending signal. PID: 23305 SIG: 9
将word = json_data.getString(result);更改为word = json_data.getString("server_response");
更新：
public void select(){
readThis hello = new readThis();
hello.execute(new String[] {url});
}
private class ReadThis extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... params) {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",id));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line);
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
}
return result ;
}
@Override
protected void onPostExecute(String result) {
try
{
JSONObject json_data = new JSONObject(result);
word = json_data.getString("server_response");
Toast.makeText(getBaseContext(), "Name: " + word,
Toast.LENGTH_SHORT).show();
}
catch(JSONException e)
{
Log.e("Fail 3", e.toString());
Log.e("log_tag", "Failed data was: " + result);
}
}
@Override
protected void onPreExecute() {}
@Override
protected void onProgressUpdate(Void... values) {}
}
JSON 是键值对，例如 {"key","value"};
您要做的是使用 JSON 对象本身获取值。
将行 word = json_data.getString(result); 更改为 word = json_data.getString("YOUR_KEY");