我在我的Android应用程序中使用asp.net web api。但它给了我一个错误。我的返回字符串是JSON格式 下面是我的日志猫
11-30 12:44:02.760: W/ActivityThread(821): Application com.example.test is waiting for the debugger on port 8100...
11-30 12:44:02.811: I/System.out(821): Sending WAIT chunk
11-30 12:44:02.820: I/dalvikvm(821): Debugger is active
11-30 12:44:02.900: I/System.out(821): Debugger has connected
11-30 12:44:02.900: I/System.out(821): waiting for debugger to settle...
11-30 12:44:03.099: I/System.out(821): waiting for debugger to settle...
11-30 12:44:03.299: I/System.out(821): waiting for debugger to settle...
11-30 12:44:03.509: I/System.out(821): waiting for debugger to settle...
11-30 12:44:03.709: I/System.out(821): waiting for debugger to settle...
11-30 12:44:03.910: I/System.out(821): waiting for debugger to settle...
11-30 12:44:04.113: I/System.out(821): waiting for debugger to settle...
11-30 12:44:04.319: I/System.out(821): waiting for debugger to settle...
11-30 12:44:04.519: I/System.out(821): waiting for debugger to settle...
11-30 12:44:04.721: I/System.out(821): waiting for debugger to settle...
11-30 12:44:04.930: I/System.out(821): debugger has settled (1324)
11-30 12:46:27.210: E/log_tag(821): Error converting result org.json.JSONException: Value [{"Name":"Panadol","Batch":"B030","Id":1,"Expiry":"12\/11\/2013","Type":"Tablet","Price":"12"},{"Name":"Velosef 500mg","Batch":"B069","Id":2,"Expiry":"06\/12\/2014","Type":"Capsule","Price":"100"},{"Name":"Tandegyl 120ml","Batch":"B097","Id":3,"Expiry":"09\/08\/2015","Type":"Syrup","Price":"120"},{"Name":"Acefyl","Batch":"B78","Id":4,"Expiry":"03\/12\/2014","Type":"Syrup","Price":"50"},{"Name":"Tyno","Batch":"B79","Id":5,"Expiry":"03\/06\/2015","Type":"Syrup","Price":"48"},{"Name":"Nocid 40mg","Batch":"BN09","Id":6,"Expiry":"11\/09\/2013","Type":"Tablet","Price":"60"},{"Name":"Lipiget 100mg","Batch":"B090","Id":7,"Expiry":"09\/09\/2015","Type":"Tablet","Price":"250"}] of type org.json.JSONArray cannot be converted to JSONObject
11-30 12:46:42.319: D/dalvikvm(821): Debugger has detached; object registry had 498 entries
11-30 12:46:42.333: I/dalvikvm(821): ignoring registerObject request in thread=1
11-30 12:46:42.333: I/dalvikvm(821): ignoring registerObject request in thread=1
11-30 12:46:42.333: D/AndroidRuntime(821): Shutting down VM
11-30 12:46:42.333: W/dalvikvm(821): threadid=1: thread exiting with uncaught exception (group=0x40015560)
11-30 12:46:42.399: E/AndroidRuntime(821): FATAL EXCEPTION: main
11-30 12:46:42.399: E/AndroidRuntime(821): java.lang.NullPointerException
11-30 12:46:42.399: E/AndroidRuntime(821): at com.example.test.Test$1$1$1.run(Test.java:63)
11-30 12:46:42.399: E/AndroidRuntime(821): at android.os.Handler.handleCallback(Handler.java:587)
11-30 12:46:42.399: E/AndroidRuntime(821): at android.os.Handler.dispatchMessage(Handler.java:92)
11-30 12:46:42.399: E/AndroidRuntime(821): at android.os.Looper.loop(Looper.java:123)
11-30 12:46:42.399: E/AndroidRuntime(821): at android.app.ActivityThread.main(ActivityThread.java:3683)
11-30 12:46:42.399: E/AndroidRuntime(821): at java.lang.reflect.Method.invokeNative(Native Method)
11-30 12:46:42.399: E/AndroidRuntime(821): at java.lang.reflect.Method.invoke(Method.java:507)
11-30 12:46:42.399: E/AndroidRuntime(821): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
11-30 12:46:42.399: E/AndroidRuntime(821): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
11-30 12:46:42.399: E/AndroidRuntime(821): at dalvik.system.NativeStart.main(Native Method)
这是我的测试课 Test.java
package com.example.test;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.Bundle;
import android.os.Handler;
import android.os.StrictMode;
import android.app.Activity;
import android.util.Log;
import android.view.View;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
public class Test extends Activity {
AutoCompleteTextView acw;
Button click;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
acw=(AutoCompleteTextView)findViewById(R.id.AndroidBooks);
click=(Button)findViewById(R.id.button1);
final Handler threadHandler;
threadHandler = new Handler();
new Thread(new Runnable(){
@Override
public void run() {
final String url="http://10.0.2.2:3325/api/ProductType";
click.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
threadHandler.post(new Runnable(){
@Override
public void run() {
List<String> temp=new ArrayList<String>();
try {
JSONObject json=executeGet(url);
Log.v("Response", json.toString());
} catch (JSONException e) {
e.printStackTrace();
}
}
});
}
});
}
}).start();
}
public static JSONObject executeGet(String url) throws JSONException
{
InputStream is = null;
String result = "";
JSONObject jArray = null;
int response=0;
HttpURLConnection connection = null;
try
{
connection = (HttpURLConnection) new URL(url).openConnection();
connection.setDoInput(true);
connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestMethod("GET");
connection.connect();
response=connection.getResponseCode();
is=connection.getInputStream();
}
catch(Exception e)
{
e.printStackTrace();
Log.e("HTTP Response", e.toString());
}
try
{
if(response==200)
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
jArray = new JSONObject(result);
}
}
catch (IOException e) {
e.printStackTrace();
}
catch(Exception e)
{
Log.e("log_tag", "Error converting result "+e.toString());
}
return jArray;
}
}
我在google上发现数据不是JSON格式。根据我的日志，我的数据是JSON格式。所以代码中有什么不对。我也使用UTF-8编码。但同样的问题。
答案 0 :(得分：1)
您正在JSONArray内阅读JSONObject ..
你需要改变：
jArray = new JSONObject(result);
要：
JSONArray jArray = new JSONArray(result);
检查http://www.androidhive.info/2012/01/android-json-parsing-tutorial/
答案 1 :(得分：1)
您正在尝试将JsonArray转换为JsonObject，因此请更改您的代码，因为在当前的json字符串中包含JsonArray而不是JsonObejct作为根元素：
try {
JSONArray jsonarray=executeGet(url);
for (int i = 0; i < jsonarray.length(); ++i) {
JSONObject jsonobject = jsonarray.getJSONObject(i);
String str_name=jsonobject.getString("Name");
String str_Batch=jsonobject.getString("Batch");
String str_Id=jsonobject.getString("Id");
String str_Expiry=jsonobject.getString("Expiry");
String str_Type=jsonobject.getString("Type");
String str_Price=jsonobject.getString("Price");
} catch (JSONException e) {
e.printStackTrace();
}
并将executeGet(String url)方法的后退类型从JsonObject更改为JSONArray
public static JSONArray executeGet(String url) throws JSONException