Question

让我给您一些有关我的数据库的信息。我使用xampp连接到MySQL。

我的问题：

以下证明我的编码没有错误。
以下证明我的应用无法检测数据库。
我认为我对BufferedReader使用了错误的ISO编码。 Youtube告诉我，不同的android studio具有不同的ISO编码。
我的数据库连接确实是真的吗？

这是我的一些代码。

数据库连接：background.java

package com.example.whatisthat;

import android.app.AlertDialog;
import android.content.Context;
import android.os.AsyncTask;

import java.io.BufferedReader;
import java.io.BufferedWriter;
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.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class background extends AsyncTask <String, Void, String> {

AlertDialog dialog;
Context context;
public background(Context context)
{
    this.context = context;
}

@Override
protected void onPreExecute() {
    dialog = new AlertDialog.Builder(context).create();
    dialog.setTitle("Login Status");
}

@Override
protected void onPostExecute(String s) {
   dialog.setMessage(s);
   dialog.show();
}

@Override
protected String doInBackground(String... voids) {
    String result = "";
    String user = voids[0];
    String pass = voids[1];

    String connstr = "http://localhost:8080/login1.php";

    try
    {
        URL url = new URL (connstr);
        HttpURLConnection http = (HttpURLConnection)    url.openConnection();
        http.setRequestMethod("POST");
        http.setDoInput(true);
        http.setDoOutput(true);

        OutputStream ops = http.getOutputStream();
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(ops, "UTF-8"));
        String data = URLEncoder.encode("user", "UTF-8")+"="+URLEncoder.encode(user, "UTF-8")
                +"&&"+URLEncoder.encode("pass", "UTF-8")+"="+URLEncoder.encode(pass, "UTF-8");
        writer.write(data);
        writer.flush();
        writer.close();
        ops.close();

        InputStream ips = http.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(ips, "ISO-8859-1"));
        String line = "";
        while ((line = reader.readLine()) != null)
        {
            result += line;
        }
        reader.close();
        ips.close();
        http.disconnect();
        return result;
    }
    catch (MalformedURLException e)
    {
        result = e.getMessage();
    }
    catch (IOException e)
    {
        result = e.getMessage();
    }

    return result;
}
}

我的登录页面：login1.java

package com.example.whatisthat;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import java.sql.Connection;

public class Login1 extends AppCompatActivity {

Button btnLogin;
EditText etUsername, etPass;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login1);

    btnLogin = findViewById(R.id.Login);
    etUsername = findViewById(R.id.Username);
    etPass = findViewById(R.id.Password);
}

public void btnRegister(View view) {
    startActivity(new Intent(getApplicationContext(), SignUp.class));
}

public void loginBtn(View view) {
    String user = etUsername.getText().toString();
    String pass = etPass.getText().toString();

    background bg = new background(this);
    bg.execute(user, pass);
}
}

我的登录页面XML文件：activity_login1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".Login1"
android:gravity="center">

<ImageView
    android:layout_width="345dp"
    android:layout_height="200dp"
    android:padding="30dp"
    android:src="@drawable/people" />

<com.google.android.material.textfield.TextInputLayout
    android:layout_width="345dp"
    android:layout_height="wrap_content"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:textColorHint="@color/colorPrimary">

    <EditText
        android:id="@+id/Username"
        android:layout_width="306dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:ems="10"
        android:hint="Username "
        android:inputType="text"
        android:textSize="20sp" />
</com.google.android.material.textfield.TextInputLayout>

<com.google.android.material.textfield.TextInputLayout
    android:layout_width="344dp"
    android:layout_height="wrap_content"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:textColorHint="@color/colorPrimary"
    app:passwordToggleEnabled="true">

    <EditText
        android:id="@+id/Password"
        android:layout_width="307dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:ems="10"
        android:hint="Password"
        android:inputType="textPassword"
        android:textSize="20sp" />
</com.google.android.material.textfield.TextInputLayout>

<Button
    android:id="@+id/Login"
    android:layout_width="281dp"
    android:layout_height="60dp"
    android:layout_marginTop="40dp"
    android:background="@drawable/button_rounded"
    android:text="Login "
    android:textColor="@color/colorAccent"
    android:textSize="20sp"
    android:onClick="loginBtn" />

<Button
    android:id="@+id/Register"
    android:layout_width="281dp"
    android:layout_height="60dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/button_rounded"
    android:onClick="btnRegister"
    android:text="Register "
    android:textColor="@color/colorAccent"
    android:textSize="20sp" />
</LinearLayout>

我的讲师说我为连接数据库输入了错误的IP地址。有人可以帮助我使此代码成功连接到我的数据库。

为什么我的数据库无法连接到登录页面？

0 个答案: