Android URL and HTTP Post Error

Question

当我尝试使用HTTP POST将数据传递到服务器时遇到问题。我想将这些数据插入数据库。但是，当我测试它时，错误显示如下"不幸的是，......已经停止了。

测试活动.java

public class TestActivity extends AppCompatActivity {
    ArrayList<Cart> cartList;
    String URL_SEND;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test);
        cartList = new ArrayList<>();
        URL_SEND = "http://192.168.56.1/api.php";
        new SendOrder().execute();
    }
    class SendOrder extends AsyncTask<Void,Void,Void> {
        @Override
        protected Void doInBackground(Void... params) {
            Cart cart1 = new Cart("1", 3);
            cartList.add(cart1);
            Cart cart2 = new Cart("2", 2);
            cartList.add(cart2);
            try {
                URL url = new URL(URL_SEND);
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setRequestProperty("Content-Type", "application/json");
                httpURLConnection.connect();
                JSONObject jsonObject = new JSONObject();
                jsonObject.put("idUser", "1");
                jsonObject.put("total", 50000);
                jsonObject.put("cartArray", new JSONArray(cartList));
                jsonObject.put("key", "12345");
                OutputStreamWriter writer = new OutputStreamWriter(httpURLConnection.getOutputStream());
                writer.write(jsonObject.toString());
                writer.flush();
                Toast.makeText(TestActivity.this, "Order success", Toast.LENGTH_LONG).show();
                cartList.clear();
            } catch (Exception e) {
                Toast.makeText(TestActivity.this, "Server error", Toast.LENGTH_LONG).show();
            }
            return null;
        }
    }
}

购物车.java

public class Cart {
    private String idMenu;
    private int quantity = 0;
    public Cart() {
    }
    public Cart(String idMenu, int quantity){
        this.idMenu = idMenu;
        this.quantity = quantity;
    }
    public String getIdMenu(){
        return idMenu;
    }
    public void setIdMenu(String idMenu) {
        this.idMenu = idMenu;
    }
    public int getQuantity() {
        return quantity;
    }
    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }
}

接口.php

<?php
if ($_SERVER['REQUEST_METHOD']=='POST'){
    include_once('../admin/connect_database.php');
    $user_id = $_POST['idUser'];
    $cartArray = $_POST['cartArray'];
    $key = $_POST['key'];
    $total= $_POST['total'];
    $status = "PENDING";
    if ($key == $keyapi) {
        $sth = $dbh->prepare("INSERT INTO order(user_id, total, status_order, time)
            VALUES(:idUser, :total, :status, :waktu)");
        $res = $sth->execute(array(
            'idUser' => $user_id,
            'total' => $total,
            'status' => $status,
            'waktu' => date()
        ));
        $id = $dbh->lastInsertId();
        foreach ($cartArray as $cart) {
            $idProduct = $cart->idMenu;
            $qty = $cart->quantity;
            $sth = $dbh->prepare('INSERT INTO order_detail(id_order, id_product, qty) VALUES (:idOrder, :idProduct, :qty)');
            $res = $sth->execute(array(
                'idOrder' => $id,
                'idProduct' => $idProduct,
                'qty' => $qty
            ));
        }
    }
}
?>

似乎 URL 本身有问题。当我只用URL url = new URL(URL_SEND);运行它时，发生了同样的错误。我不知道为什么这段代码不起作用。

编辑

这是我得到的错误。

FATAL EXCEPTION: AsyncTask #1
Process: com.catering.catering, PID: 5219
java.lang.RuntimeException: An error occurred while executing doInBackground()
    at android.os.AsyncTask$3.done(AsyncTask.java:309)
    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
    at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
    at java.util.concurrent.FutureTask.run(FutureTask.java:242)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
    at java.lang.Thread.run(Thread.java:818)
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$TN.<init>(Toast.java:345)
    at android.widget.Toast.<init>(Toast.java:101)
    at android.widget.Toast.makeText(Toast.java:259)
    at com.catering.catering.TestActivity$SendOrder.doInBackground(TestActivity.java:90)
    at com.catering.catering.TestActivity$SendOrder.doInBackground(TestActivity.java:57)
    at android.os.AsyncTask$2.call(AsyncTask.java:295)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
    at java.lang.Thread.run(Thread.java:818) 

Answer 1

你不应该在后台线程中做UI的东西。删除 doInBackground(( 中 Toast 的显示。如果您想确定 POST 是否成功，我建议您根据您的实现返回一个布尔对象。

public class SendOrder extends AsyncTask<Void,Void,Boolean> {
            @Override
            public void onPostExecute(Boolean result) {
                if(result != null && result) {
                   Toast.makeText(TestActivity.this, "Order success", Toast.LENGTH_LONG).show();
                }
                else {
                   Toast.makeText(TestActivity.this, "Order error", Toast.LENGTH_LONG).show();
                }
            }

            @Override
            protected Boolean doInBackground(Void... params) {
                Cart cart1 = new Cart("1", 3);
                cartList.add(cart1);
                Cart cart2 = new Cart("2", 2);
                cartList.add(cart2);
                try {
                    URL url = new URL(URL_SEND);
                    HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                    httpURLConnection.setDoOutput(true);
                    httpURLConnection.setRequestMethod("POST");
                    httpURLConnection.setRequestProperty("Content-Type", "application/json");
                    httpURLConnection.connect();
                    JSONObject jsonObject = new JSONObject();
                    jsonObject.put("idUser", "1");
                    jsonObject.put("total", 50000);
                    jsonObject.put("cartArray", new JSONArray(cartList));
                    jsonObject.put("key", "12345");
                    OutputStreamWriter writer = new OutputStreamWriter(httpURLConnection.getOutputStream());
                    writer.write(jsonObject.toString());
                    writer.flush();
                    cartList.clear();
                    return true;
                } catch (Exception e) {
                    // Your code to Log the error 
                    return false;
                }

            }
        }
}

Answer 2

从 doInBackground(( 中删除这些行：

Toast.makeText(TestActivity.this, "Order success", Toast.LENGTH_LONG).show();

和

Toast.makeText(TestActivity.this, "Server error", Toast.LENGTH_LONG).show();

你不能在doInBackground((中做UI工作：你必须在onPostExecute((中烘烤这些数据：

请参阅此链接： https://stackoverflow.com/a/18948837/6756514