Android-PHP/MYSQL示例

我是一个机器人初学者

我使用的是安卓1.0版

我尝试从网页复制代码并修改

hishttp://www.tutorialspoint.com/android/android_php_mysql.htm

my src/com.example.phpmysql/MainActivity.java

    package com.example.a014.phpmysql;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    private EditText usernameField,passwordField;
    private TextView status,role,method;

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

        usernameField = (EditText)findViewById(R.id.editText1);
        passwordField = (EditText)findViewById(R.id.editText2);

        status = (TextView)findViewById(R.id.textView6);
        role = (TextView)findViewById(R.id.textView7);
        method = (TextView)findViewById(R.id.textView9);
    }



    public void login(View view){
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Get Method");
        new SigninActivity(this,status,role,0).execute(username,password);

    }

    public void loginPost(View view){
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Post Method");
        new SigninActivity(this,status,role,1).execute(username,password);
    }
}

package com.example.a014.phpmysql;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.content.Context;
import android.os.AsyncTask;
import android.widget.TextView;

public class SigninActivity  extends AsyncTask{
    private TextView statusField,roleField;
    private Context context;
    private int byGetOrPost = 0;

    //flag 0 means get and 1 means post.(By default it is get.)
    public SigninActivity(Context context,TextView statusField,TextView roleField,int flag) {
        this.context = context;
        this.statusField = statusField;
        this.roleField = roleField;
        byGetOrPost = flag;
    }

    protected void onPreExecute(){
    }

    @Override
    protected String doInBackground(String... arg0) {
        if(byGetOrPost == 0){ //means by Get Method

            try{
                String username = (String)arg0[0];
                String password = (String)arg0[1];
                String link = "http://myphpmysqlweb.hostei.com/login.php?username="+username+"& password="+password;

                URL url = new URL(link);
                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet();
                request.setURI(new URI(link));
                HttpResponse response = client.execute(request);
                BufferedReader in = new BufferedReader(new
                        InputStreamReader(response.getEntity().getContent()));

                StringBuffer sb = new StringBuffer("");
                String line="";

                while ((line = in.readLine()) != null) {
                    sb.append(line);
                    break;
                }

                in.close();
                return sb.toString();
            } catch(Exception e){
                return new String("Exception: " + e.getMessage());
            }
        } else{
            try{
                String username = (String)arg0[0];
                String password = (String)arg0[1];

                String link="http://myphpmysqlweb.hostei.com/loginpost.php";
                String data  = URLEncoder.encode("username", "UTF-8") + "=" +
                        URLEncoder.encode(username, "UTF-8");
                data += "&" + URLEncoder.encode("password", "UTF-8") + "=" +
                        URLEncoder.encode(password, "UTF-8");

                URL url = new URL(link);
                URLConnection conn = url.openConnection();

                conn.setDoOutput(true);
                OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

                wr.write( data );
                wr.flush();

                BufferedReader reader = new BufferedReader(new
                        InputStreamReader(conn.getInputStream()));

                StringBuilder sb = new StringBuilder();
                String line = null;

                // Read Server Response
                while((line = reader.readLine()) != null) {
                    sb.append(line);
                    break;
                }

                return sb.toString();
            } catch(Exception e){
                return new String("Exception: " + e.getMessage());
            }
        }
    }

    @Override
    protected void onPostExecute(String result){
        this.statusField.setText("Login Successful");
        this.roleField.setText(result);
    }
}

my src/com.example.phpmysql/SigninActivity.java

    package com.example.a014.phpmysql;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    private EditText usernameField,passwordField;
    private TextView status,role,method;

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

        usernameField = (EditText)findViewById(R.id.editText1);
        passwordField = (EditText)findViewById(R.id.editText2);

        status = (TextView)findViewById(R.id.textView6);
        role = (TextView)findViewById(R.id.textView7);
        method = (TextView)findViewById(R.id.textView9);
    }



    public void login(View view){
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Get Method");
        new SigninActivity(this,status,role,0).execute(username,password);

    }

    public void loginPost(View view){
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Post Method");
        new SigninActivity(this,status,role,1).execute(username,password);
    }
}

package com.example.a014.phpmysql;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.content.Context;
import android.os.AsyncTask;
import android.widget.TextView;

public class SigninActivity  extends AsyncTask{
    private TextView statusField,roleField;
    private Context context;
    private int byGetOrPost = 0;

    //flag 0 means get and 1 means post.(By default it is get.)
    public SigninActivity(Context context,TextView statusField,TextView roleField,int flag) {
        this.context = context;
        this.statusField = statusField;
        this.roleField = roleField;
        byGetOrPost = flag;
    }

    protected void onPreExecute(){
    }

    @Override
    protected String doInBackground(String... arg0) {
        if(byGetOrPost == 0){ //means by Get Method

            try{
                String username = (String)arg0[0];
                String password = (String)arg0[1];
                String link = "http://myphpmysqlweb.hostei.com/login.php?username="+username+"& password="+password;

                URL url = new URL(link);
                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet();
                request.setURI(new URI(link));
                HttpResponse response = client.execute(request);
                BufferedReader in = new BufferedReader(new
                        InputStreamReader(response.getEntity().getContent()));

                StringBuffer sb = new StringBuffer("");
                String line="";

                while ((line = in.readLine()) != null) {
                    sb.append(line);
                    break;
                }

                in.close();
                return sb.toString();
            } catch(Exception e){
                return new String("Exception: " + e.getMessage());
            }
        } else{
            try{
                String username = (String)arg0[0];
                String password = (String)arg0[1];

                String link="http://myphpmysqlweb.hostei.com/loginpost.php";
                String data  = URLEncoder.encode("username", "UTF-8") + "=" +
                        URLEncoder.encode(username, "UTF-8");
                data += "&" + URLEncoder.encode("password", "UTF-8") + "=" +
                        URLEncoder.encode(password, "UTF-8");

                URL url = new URL(link);
                URLConnection conn = url.openConnection();

                conn.setDoOutput(true);
                OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

                wr.write( data );
                wr.flush();

                BufferedReader reader = new BufferedReader(new
                        InputStreamReader(conn.getInputStream()));

                StringBuilder sb = new StringBuilder();
                String line = null;

                // Read Server Response
                while((line = reader.readLine()) != null) {
                    sb.append(line);
                    break;
                }

                return sb.toString();
            } catch(Exception e){
                return new String("Exception: " + e.getMessage());
            }
        }
    }

    @Override
    protected void onPostExecute(String result){
        this.statusField.setText("Login Successful");
        this.roleField.setText(result);
    }
}

我的身材，格雷德尔

apply plugin: 'com.android.application'

android {
    useLibrary 'org.apache.http.legacy'
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.a014.phpmysql"
        minSdkVersion 17
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'org.jbundle.util.osgi.wrapped:org.jbundle.util.osgi.wrapped.org.apache.http.client:4.1.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.android.volley:volley:1.1.0'
}

my activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText1"
        android:layout_alignRight="@+id/editText1"
        android:ems="10"
        android:inputType="textPassword"
        tools:layout_editor_absoluteX="85dp"
        tools:layout_editor_absoluteY="90dp"></EditText>

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:ems="10"
        tools:layout_editor_absoluteX="85dp"
        tools:layout_editor_absoluteY="164dp">

        <requestFocus android:layout_width="wrap_content" />

    </EditText>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/editText1"
        android:layout_alignParentLeft="true"
        android:text="@string/Username"
        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="105dp" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:text="@string/App"
        android:textAppearance="?android:attr/textAppearanceLarge"
        tools:layout_editor_absoluteX="136dp"
        tools:layout_editor_absoluteY="22dp" />

    <TextView
        android:id="@+id/textView7"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_alignLeft="@+id/textView6"
        android:layout_alignBottom="@+id/textView5"
        android:text="@string/Role"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textSize="10sp"
        tools:layout_editor_absoluteX="136dp"
        tools:layout_editor_absoluteY="432dp" />

    <TextView
        android:id="@+id/textView5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView6"
        android:layout_toLeftOf="@+id/editText1"
        android:text="@string/LoginRole"
        tools:layout_editor_absoluteX="7dp"
        tools:layout_editor_absoluteY="345dp" />

    <TextView
        android:id="@+id/textView8"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textView6"
        android:layout_alignLeft="@+id/textView5"
        android:text="@string/method"
        tools:layout_editor_absoluteX="7dp"
        tools:layout_editor_absoluteY="428dp" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_alignLeft="@+id/textView8"
        android:text="@string/LoginStatus"
        tools:layout_editor_absoluteX="7dp"
        tools:layout_editor_absoluteY="383dp" />


    <TextView
        android:id="@+id/textView6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/textView4"
        android:layout_centerHorizontal="true"
        android:text="@string/Status"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textSize="10sp"
        tools:layout_editor_absoluteX="136dp"
        tools:layout_editor_absoluteY="383dp" />

    <TextView
        android:id="@+id/textView9"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView6"
        android:layout_alignBottom="@+id/textView8"
        android:text="@string/Choose"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textSize="10sp"
        tools:layout_editor_absoluteX="136dp"
        tools:layout_editor_absoluteY="345dp" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/textView6"
        android:onClick="loginPost"
        android:text="@string/LoginPost"
        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="260dp" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button2"
        android:layout_alignLeft="@+id/textView2"
        android:layout_alignBottom="@+id/button2"
        android:onClick="login"
        android:text="@string/LoginGet"
        tools:layout_editor_absoluteX="238dp"
        tools:layout_editor_absoluteY="260dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/editText2"
        android:layout_alignBottom="@+id/editText2"
        android:layout_alignParentLeft="true"
        android:text="@string/Password"
        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="179dp" />


</android.support.constraint.ConstraintLayout>

故障管理员告诉我如何纠正错误，以便他可以运行此步骤

转到文件->使缓存无效/重新启动

关闭Android Studio

重命名/删除用户主目录中的.gradle文件夹

重新启动Android Studio（它将下载gradle元数据和数据）

渐变构建成功

重建项目。完成了

---

检查此消息上方的日志。它将显示您需要修复的确切内容我很好奇，为什么您不通过一个易于调用的api简单地公开您的mysql数据库呢？php的方式似乎很复杂