我正在尝试解析JSON，我之前已经在那里完成了，但这种方式并不安静。我花了好几个小时试图解决问题，但我不知道代码有什么问题。我附加了活动，Web请求类和布局的整个代码。任何帮助将不胜感激。
我收到此错误
java.io.FileNotFoundException: /data/system/users/sdp_engine_list.xml: open failed: ENOENT (No such file or directory)
05-19 18:17:27.427 3450-3450/? W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
05-19 18:17:28.232 3450-3592/? W/DisplayManagerService: Failed to notify process 20004 that displays changed, assuming it died.
这是活动交易类。
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
import com.rectuca.iyzicodemo.Classes.Transaction;
import com.rectuca.iyzicodemo.Library.WebRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class Transactions extends ListActivity {
// URL to get contacts JSON
private static String url = "http://www.mocky.io/v2/573dbd243700005f194dcdcc";
// JSON Node names
private static final String TAG_PAYMENTS= "payments";
private static final String TAG_PAYMENT_ID = "paymentId";
private static final String TAG_SENT_BY = "sentBy";
private static final String TAG_DATE_TIME = "dateTime";
private static final String TAG_SENT_TO = "sentTo";
private static final String TAG_BANK_NAME = "bankName";
private static final String TAG_INSTALLMENTS = "installments";
private static final String TAG_AMOUNT = "amount";
private static final String TAG_3DS = "threeDs";
private static final String TAG_CANCELLED = "cancelled";
private static final String TAG_RETURNED = "returned";
private static final String TAG_TRANSACTION_STATUS = "transactionStatus";
private static final String TAG_BLOCKAGE_AMOUNT = "blockage_amount";
private static final String TAG_BLOCKAGE_RELEASE_DATE = "blockageReleaseDate";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_transactions);
// Calling async task to get json
new GetInfo().execute();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetInfo extends AsyncTask<Void, Void, Void> {
// Hashmap for ListView
ArrayList<HashMap<String, String>> transactionInfoList;
ProgressDialog proDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress loading dialog
proDialog = new ProgressDialog(Transactions.this);
proDialog.setMessage("Please Wait...");
proDialog.setCancelable(false);
proDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
WebRequest webReq = new WebRequest();
// Making a request to url and getting response
String jsonStr = webReq.makeWebServiceCall(url, WebRequest.GET);
Log.d("Response: ", "> " + jsonStr);
transactionInfoList = ParseJSON(jsonStr);
return null;
}
@Override
protected void onPostExecute(Void requestresult) {
super.onPostExecute(requestresult);
// Dismiss the progress dialog
if (proDialog.isShowing())
proDialog.dismiss();
/**
* Updating received data from JSON into ListView
* */
transactionInfoList=new ArrayList<HashMap<String, String>>();
ListAdapter adapter = new SimpleAdapter(
Transactions.this, transactionInfoList,
R.layout.row_layout, new String[]{TAG_SENT_TO,TAG_DATE_TIME
,TAG_BANK_NAME,TAG_AMOUNT,TAG_3DS, TAG_CANCELLED,
TAG_RETURNED},
new int[]{R.id.name,R.id.dateTime ,R.id.bankName,R.id.amount,
R.id.threeDS, R.id.cancelled, R.id.returned});
setListAdapter(adapter);
}
}
private ArrayList<HashMap<String, String>> ParseJSON(String json) {
if (json != null) {
try {
// Hashmap for ListView
ArrayList<HashMap<String, String>> paymentList = new ArrayList<HashMap<String, String>>();
JSONObject jsonObj = new JSONObject(json);
// Getting JSON Array node
JSONArray payments = jsonObj.getJSONArray(TAG_PAYMENTS);
// looping through All Payments
for (int i = 0; i < payments.length(); i++) {
JSONObject c = payments.getJSONObject(i);
String dateTime =c.getString(TAG_DATE_TIME);
String sentTo =c.getString(TAG_SENT_TO);
String bankName =c.getString(TAG_BANK_NAME)+" ( "+c.getString(TAG_INSTALLMENTS)+" ) " ;
String amount =c.getString(TAG_AMOUNT);
String threeDS =c.getString(TAG_3DS);
String cancelled =c.getString(TAG_CANCELLED);
String returned =c.getString(TAG_RETURNED);
// temporary hashmap for a single payment
HashMap<String, String> payment = new HashMap<String, String>();
// adding every child node to HashMap key => value
payment.put(TAG_DATE_TIME, dateTime);
payment.put(TAG_SENT_TO, sentTo);
payment.put(TAG_BANK_NAME, bankName);
payment.put(TAG_AMOUNT, amount);
payment.put(TAG_3DS, threeDS);
payment.put(TAG_CANCELLED, cancelled);
payment.put(TAG_RETURNED, returned);
// adding student to students list
paymentList.add(payment);
}
return paymentList;
} catch (JSONException e) {
e.printStackTrace();
return null;
}
} else {
Log.e("ServiceHandler", "No data received from HTTP Request");
return null;
}
}
}
这是WebRequest类
package com.rectuca.iyzicodemo.Library;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import javax.net.ssl.HttpsURLConnection;
public class WebRequest {
static String response = null;
public final static int GET = 1;
public final static int POST = 2;
//Constructor with no parameter
public WebRequest() {
}
/**
* Making web service call
*
* @url - url to make request
* @requestmethod - http request method
*/
public String makeWebServiceCall(String url, int requestmethod) {
return this.makeWebServiceCall(url, requestmethod, null);
}
/**
* Making service call
*
* @url - url to make request
* @requestmethod - http request method
* @params - http request params
*/
public String makeWebServiceCall(String urladdress, int requestmethod,
HashMap<String, String> params) {
URL url;
String response = "";
try {
url = new URL(urladdress);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(15000);
conn.setConnectTimeout(15000);
conn.setDoInput(true);
conn.setDoOutput(true);
if (requestmethod == POST) {
conn.setRequestMethod("POST");
} else if (requestmethod == GET) {
conn.setRequestMethod("GET");
}
if (params != null) {
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
StringBuilder result = new StringBuilder();
boolean first = true;
for (Map.Entry<String, String> entry : params.entrySet()) {
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
writer.write(result.toString());
writer.flush();
writer.close();
os.close();
}
int responseCode = conn.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK) {
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = br.readLine()) != null) {
response += line;
}
} else {
response = "";
}
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
}
这就是我想要做的事情
答案 0 :(得分：1)
我建议你使用 谷歌的VOLLEY网络库
您应该尝试使用Volley JSONOBJECTREQUEST（）并且在解析之后您将不会遇到任何问题。
将此添加到应用的依赖项部分
function convertImgToDataURLviaCanvas(url){
var img = new Image();
img.crossOrigin = 'Anonymous';
img.onload = function(){
var canvas = document.createElement('CANVAS');
var ctx = canvas.getContext('2d');
var dataURL;
canvas.height = this.height;
canvas.width = this.width;
ctx.drawImage(this, 0, 0);
dataURL = canvas.toDataURL("image/png");
canvas = null;
};
img.src = url;
}
function convertFileToDataURLviaFileReader(url){
var xhr = new XMLHttpRequest();
xhr.responseType = 'blob';
xhr.onload = function() {
var reader = new FileReader();
reader.onloadend = function () {
console.log(reader.result);
}
reader.readAsDataURL(xhr.response);
};
xhr.open('GET', url);
xhr.send();
}