Die folgende Klasse ApiUrlClass.java verfügt über alle Methoden, die Sie benötigen. Bitte lies die Kommentare der Klasse, die ich geschrieben habe. Das wird Ihnen helfen, das zu tun, was Sie benötigen. Dies nutzt auch transparent.
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.util.Log;
import org.apache.http.entity.mime.HttpMultipartMode;
import org.apache.http.entity.mime.content.ByteArrayBody;
import org.apache.http.entity.mime.content.ContentBody;
import org.apache.http.entity.mime.content.StringBody;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.net.UnknownHostException;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLPeerUnverifiedException;
/*
Usage of the class
Create all the necessary API Call methods you need.
And either use a Thread or AsyncTask to call the following.
JSONObject response = ApiUrlCalls.login("username", "passowrd");
After the response is obtained, check for status code like
if(response.getInt("status_code") == 200){
//TODO: code something
} else {
//TODO: code something
}
*/
public class ApiUrlCalls {
private String HOST = "https://domain/path/"; //This will be concated with the function needed. Ref:1
/*
Now utilizing the method is so simple. Lets consider a login function, which sends username and password.
See below for example.
*/
public static JSONObject login(String username, String password){
String functionCall = "login";
Uri.Builder builder = new Uri.Builder()
.appendQueryParameter("username", username)
.appendQueryParameter("password", password);
/*
The return calls the apiPost method for processing.
Make sure this should't happen in the UI thread, orelse, NetworkOnMainThread exception will be thrown.
*/
return apiPost(builder, functionCall);
}
/*
This method is the one which performs POST operation. If you need GET, just change it
in like Connection.setRequestMethod("GET")
*/
private static JSONObject apiPost(Uri.Builder builder, String function){
try {
int TIMEOUT = 15000;
JSONObject jsonObject = new JSONObject();
try {
URL url = null;
String response = "";
/*
Ref:1
As mentioned, here below, in case the function is "login",
url looks like https://domain/path/login
This is generally a rewrited form by .htaccess in server.
If you need knowledge on RESTful API in PHP, refer
http://stackoverflow.com/questions/34997738/creating-restful-api-what-kind-of-headers-should-be-put-out-before-the-response/35000332#35000332
I have answered how to create a RESTful API. It matches the above URL format, it also includes the .htaccess
*/
url = new URL(HOST + function);
HttpsURLConnection conn = null;
conn = (HttpsURLConnection) url.openConnection();
assert conn != null;
conn.setReadTimeout(TIMEOUT);
conn.setConnectTimeout(TIMEOUT);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
String query = builder.build().getEncodedQuery();
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
conn.connect();
int responseCode = conn.getResponseCode();
String responseMessage = conn.getResponseMessage();
jsonObject.put("status_code", responseCode);
jsonObject.put("status_message", responseMessage);
/*The if condition below will check if status code is greater than 400 and sets error status
even before trying to read content, because HttpUrlConnection classes will throw exceptions
for status codes 4xx and 5xx. You cannot read content for status codes 4xx and 5xx in HttpUrlConnection
classes.
*/
if (jsonObject.getInt("status_code") >= 400) {
jsonObject.put("status", "Error");
jsonObject.put("msg", "Something is not good. Try again later.");
return jsonObject;
}
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = br.readLine()) != null) {
response += line;
}
//Log.d("RESP", response);
/*
After the actual payload is read as a string, it is time to change it into JSON.
Simply when it starts with "[" it should be a JSON array and when it starts with "{"
it is a JSONObject. That is what hapenning below.
*/
if(response.startsWith("[")) {
jsonObject.put("content", new JSONArray(response));
}
if(response.startsWith("{")){
jsonObject.put("content", new JSONObject(response));
}
} catch(UnknownHostException e) {
//No explanation needed :)
jsonObject.put("status", "UnknownHostException");
jsonObject.put("msg", "Check your internet connection");
} catch (SocketTimeoutException){
//This is when the connection timeouts. Timeouts can be modified by TIMEOUT variable above.
jsonObject.put("status", "Timeout");
jsonObject.put("msg", "Check your internet connection");
} catch (SSLPeerUnverifiedException se) {
//When an untrusted SSL Certificate is received, this happens. (Only for https.)
jsonObject.put("status", "SSLException");
jsonObject.put("msg", "Unable to establish secure connection.");
se.printStackTrace();
} catch (IOException e) {
//This generally happens when there is a trouble in connection
jsonObject.put("status", "IOException");
jsonObject.put("msg", "Check your internet connection");
e.printStackTrace();
} catch(FileNotFoundException e){
//There is no chance that this catch block will execute as we already checked for 4xx errors
jsonObject.put("status", "FileNotFoundException");
jsonObject.put("msg", "Some 4xx Error");
e.printStackTrace();
} catch (JSONException e){
//This happens when there is a troble reading the content, or some notice or warnings in content,
//which generally happens while we modify the server side files. Read the "msg", and it is clear now :)
jsonObject.put("status", "JSONException");
jsonObject.put("msg", "We are experiencing a glitch, try back in sometime.");
e.printStackTrace();
} return jsonObject;
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
Können Sie angeben, wie groß ist es? wie über xxx Mb? Laden Sie den gesamten JSON herunter und das Parsen kann teuer sein. – sakiM
Warum holen Sie es von einem Server und warum speichern Sie es als JSON, wenn es statisch ist und in der App versendet werden kann? – rds
Dieses Problem ist nicht wegen der JSON-Datei, es gibt etwas anderes, das Sie übersehen. Sie sollten logcat-Ausgabe anhängen, wenn Sie eine Lösung wünschen. – chandil03