Android开发学习笔记整理（16）-网络请求
16lz
2021-01-23
代码部分：
part1：
logo.png
mobile.png
secret.png
btn_shape.xml
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"> <solid android:color="#32C999"/> <corners android:radius="30dp"/>shape>效果图：
activity_main.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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"> <ImageView android:id="@+id/imageView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="50dp" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@drawable/logo" /> <LinearLayout android:id="@+id/linearLayout" android:layout_width="0dp" android:layout_height="60dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginTop="30dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/imageView"> <ImageView android:id="@+id/imageView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" app:srcCompat="@drawable/mobile" /> <EditText android:id="@+id/et_mobile" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:background="@null" android:ems="10" android:hint="请输入手机号" android:inputType="phone" /> LinearLayout> <View android:id="@+id/view" android:layout_width="0dp" android:layout_height="1dp" android:background="#DFDDDD" app:layout_constraintEnd_toEndOf="@+id/linearLayout" app:layout_constraintStart_toStartOf="@+id/linearLayout" app:layout_constraintTop_toBottomOf="@+id/linearLayout" /> <LinearLayout android:id="@+id/linearLayout2" android:layout_width="match_parent" android:layout_height="60dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginTop="30dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="@+id/view"> <ImageView android:id="@+id/imageView3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" app:srcCompat="@drawable/secret" /> <EditText android:id="@+id/et_password" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:background="@null" android:ems="10" android:hint="请输入密码" android:inputType="textPassword" /> LinearLayout> <View android:id="@+id/view2" android:layout_width="0dp" android:layout_height="1dp" android:background="#DFDDDD" app:layout_constraintEnd_toEndOf="@+id/linearLayout2" app:layout_constraintStart_toStartOf="@+id/linearLayout2" app:layout_constraintTop_toBottomOf="@+id/linearLayout2" /> <Button android:id="@+id/button" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginTop="40dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:background="@drawable/btn_shape" android:onClick="login" android:text="登录" android:textColor="#FFFFFF" android:textSize="20sp" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/view2" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:background="@null" android:text="忘记密码" app:layout_constraintStart_toStartOf="@+id/button" app:layout_constraintTop_toBottomOf="@+id/button" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:background="@null" android:onClick="register" android:text="注册" app:layout_constraintEnd_toEndOf="@+id/button" app:layout_constraintTop_toBottomOf="@+id/button" />androidx.constraintlayout.widget.ConstraintLayout>效果图：
activity_register.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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=".RegisterActivity"> <ImageView android:id="@+id/imageView4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="30dp" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@drawable/logo" /> <LinearLayout android:id="@+id/linearLayout3" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginTop="30dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/imageView4"> <ImageView android:id="@+id/imageView5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" app:srcCompat="@drawable/mobile" /> <EditText android:id="@+id/et_mobile" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:background="@null" android:ems="10" android:hint="请输入手机号" android:inputType="phone" /> LinearLayout> <View android:id="@+id/view3" android:layout_width="0dp" android:layout_height="1dp" android:background="#DFdddd" app:layout_constraintEnd_toEndOf="@+id/linearLayout3" app:layout_constraintStart_toStartOf="@+id/linearLayout3" app:layout_constraintTop_toBottomOf="@+id/linearLayout3" /> <LinearLayout android:id="@+id/linearLayout4" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginTop="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="@+id/linearLayout3" app:layout_constraintStart_toStartOf="@+id/linearLayout3" app:layout_constraintTop_toBottomOf="@+id/linearLayout3"> <ImageView android:id="@+id/imageView6" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" app:srcCompat="@drawable/secret" /> <EditText android:id="@+id/et_password" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:background="@null" android:ems="10" android:hint="请输入密码" android:inputType="textPassword" /> LinearLayout> <View android:id="@+id/view4" android:layout_width="0dp" android:layout_height="1dp" android:background="#DFDDDD" app:layout_constraintEnd_toEndOf="@+id/linearLayout4" app:layout_constraintStart_toStartOf="@+id/linearLayout4" app:layout_constraintTop_toBottomOf="@+id/linearLayout4" /> <LinearLayout android:id="@+id/linearLayout5" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginTop="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="@+id/linearLayout4" app:layout_constraintStart_toStartOf="@+id/linearLayout4" app:layout_constraintTop_toBottomOf="@+id/view4"> <ImageView android:id="@+id/imageView7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" app:srcCompat="@drawable/secret" /> <EditText android:id="@+id/et_repassword" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:background="@null" android:ems="10" android:hint="请确认密码" android:inputType="textPassword" /> LinearLayout> <View android:id="@+id/view5" android:layout_width="0dp" android:layout_height="1dp" android:background="#DDDDDD" app:layout_constraintEnd_toEndOf="@+id/linearLayout5" app:layout_constraintStart_toStartOf="@+id/linearLayout5" app:layout_constraintTop_toBottomOf="@+id/linearLayout5" /> <Button android:id="@+id/button4" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginTop="30dp" android:background="@drawable/btn_shape" android:onClick="register" android:text="注册" android:textColor="#FFFFFF" android:textSize="20sp" app:layout_constraintEnd_toEndOf="@+id/linearLayout5" app:layout_constraintStart_toStartOf="@+id/linearLayout5" app:layout_constraintTop_toBottomOf="@+id/view5" /> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="@+id/button4" app:layout_constraintStart_toStartOf="@+id/button4" app:layout_constraintTop_toBottomOf="@+id/button4"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="已有账号，" android:textColor="#111111" /> <Button android:id="@+id/button5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@null" android:text="立即登录" android:textColor="#32C999" /> LinearLayout>androidx.constraintlayout.widget.ConstraintLayout>效果图：
RegisterActivity.java
import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Log;import android.view.View;import android.widget.EditText;import android.widget.Toast;import org.json.JSONException;import org.json.JSONObject;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;public class RegisterActivity extends AppCompatActivity { private EditText et_mobile; private EditText et_password; private EditText et_repassword; private Handler handler = new Handler(){ @Override public void handleMessage(@NonNull Message msg) { // 提示注册成功了 if ("200".equals(msg.obj)) { Toast.makeText(RegisterActivity.this,"注册成功", Toast.LENGTH_SHORT).show(); startActivity(new Intent(RegisterActivity.this, MainActivity.class)); } else { Toast.makeText(RegisterActivity.this,"注册失败", Toast.LENGTH_SHORT).show(); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_register); et_mobile = findViewById(R.id.et_mobile); et_password = findViewById(R.id.et_password); et_repassword = findViewById(R.id.et_repassword); } /** * 注册 * @param view */ public void register(View view) { // 判断手机号是否为空 final String mobile = et_mobile.getText().toString().trim(); if ("".equals(mobile)) { Toast.makeText(this, "请输入手机号", Toast.LENGTH_SHORT).show(); return; } // 判断密码是否为空 final String password = et_password.getText().toString().trim(); if ("".equals(password)) { Toast.makeText(this, "请输入密码", Toast.LENGTH_SHORT).show(); return; } // 判断两次输入的密码 String repassword = et_repassword.getText().toString().trim(); if (!password.equals(repassword)) { Toast.makeText(this, "两次输入的密码不一致", Toast.LENGTH_SHORT).show(); return; } // 发起http请求，进行注册,凡是费时的操作，要放到线程中去做 new Thread(new Runnable() { @Override public void run() { HttpURLConnection connection = null; try { URL url = new URL("http://121.36.161.94:8080/register"); connection = (HttpURLConnection) url.openConnection(); // 设置请求方式 connection.setRequestMethod("POST"); String param = "username="+mobile+"&password="+password; // 获取输出流并输出参数 OutputStream outputStream = connection.getOutputStream(); outputStream.write(param.getBytes()); outputStream.close(); // 接收返回值 InputStream inputStream = connection.getInputStream(); int i = inputStream.read(); StringBuffer response = new StringBuffer(); while(i != -1) { response.append((char)i); i = inputStream.read(); } inputStream.close(); // 输出结果 Log.i("RegisterActivity", response.toString()); // {"code":"200","msg":"success","data":null}称为json数据 JSONObject jsonObject = new JSONObject(response.toString()); String string = jsonObject.getString("code"); Message message = new Message(); message.obj = string; handler.sendMessage(message); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (JSONException e) { e.printStackTrace(); } finally { if (connection != null) { connection.disconnect(); } } } }).start(); }}IndexActivity.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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=".IndexActivity">androidx.constraintlayout.widget.ConstraintLayout>IndexActivity.java
import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;public class IndexActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_index); }}AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.day15"> <uses-permission android:name="android.permission.INTERNET" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme" android:usesCleartextTraffic="true"> <activity android:name=".IndexActivity">activity> <activity android:name=".RegisterActivity" /> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> intent-filter> activity> application>manifest>MainActivity.java
import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.EditText;import android.widget.Toast;import org.json.JSONObject;import java.io.InputStream;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;public class MainActivity extends AppCompatActivity { private EditText et_mobile; private EditText et_password; private Handler handler = new Handler(){ @Override public void handleMessage(@NonNull Message msg) { // 处理登录成功后 if ("200".equals(msg.obj)) { Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_SHORT).show(); startActivity(new Intent(MainActivity.this, IndexActivity.class)); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_mobile = findViewById(R.id.et_mobile); et_password = findViewById(R.id.et_password); } /** * 注册 * @param view */ public void register(View view) { Intent intent = new Intent(this, RegisterActivity.class); startActivity(intent); } /** * 登录 * @param view */ public void login(View view) { final String username = et_mobile.getText().toString().trim(); if ("".equals(username)) { Toast.makeText(this, "用户名不能为空", Toast.LENGTH_SHORT).show(); return; } final String password = et_password.getText().toString().trim(); if ("".equals(password)) { Toast.makeText(this, "密码不能为空", Toast.LENGTH_SHORT).show(); } // 发送请求 new Thread(new Runnable() { @Override public void run() { HttpURLConnection connection = null; try { URL url = new URL("http://121.36.161.94:8080/login"); connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); // 向服务器传递参数 String param = "username="+username+"&password="+password; OutputStream out = connection.getOutputStream(); out.write(param.getBytes()); out.close(); // 获取从服务器返回的数据 InputStream in = connection.getInputStream(); StringBuffer response = new StringBuffer(); int i = in.read(); while (i != -1) { response.append((char)i); i = in.read(); } in.close(); // 提示登陆成功，并跳转主页 JSONObject jsonObject = new JSONObject(response.toString()); Message message = new Message(); message.obj = jsonObject.getString("code"); handler.sendMessage(message); } catch (Exception e) { e.printStackTrace(); } } }).start(); }}part2：
rignt.png
add.png
book.png
back.png
btn_edit_shape.xml
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"> <solid android:color="#32C999"/> <corners android:radius="2dp"/>shape>效果图：
btn_delete_shape.xml
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"> <solid android:color="#E8BD48"/> <corners android:radius="2dp"/>shape>效果图：
activity_index.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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=".IndexActivity"> <LinearLayout android:id="@+id/linearLayout6" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:onClick="bookList" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent"> <ImageView android:id="@+id/imageView8" android:layout_width="24dp" android:layout_height="24dp" android:layout_gravity="center_vertical" app:srcCompat="@drawable/book" /> <TextView android:id="@+id/textView2" android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1" android:gravity="center_vertical" android:text="书籍管理" android:textColor="#111111" android:textSize="20sp" /> <ImageView android:id="@+id/imageView9" android:layout_width="24dp" android:layout_height="24dp" android:layout_gravity="center_vertical" app:srcCompat="@drawable/right" /> LinearLayout> <View android:id="@+id/view6" android:layout_width="0dp" android:layout_height="1dp" android:background="#DDDDDD" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/linearLayout6" />androidx.constraintlayout.widget.ConstraintLayout>效果图：
title.xml
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="50dp" android:background="#32C999" > <ImageButton android:id="@+id/btn_back" android:layout_width="24dp" android:layout_height="24dp" app:srcCompat="@drawable/back" android:background="@null" android:layout_centerVertical="true" android:layout_marginLeft="20dp"/> <TextView android:id="@+id/tv_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="书籍列表" android:layout_centerInParent="true" android:textColor="#111111" android:textSize="20sp" /> <ImageButton android:id="@+id/btn_edit" android:layout_width="24dp" android:layout_height="24dp" app:srcCompat="@drawable/add" android:layout_alignParentRight="true" android:background="@null" android:layout_centerVertical="true" android:layout_marginRight="20dp"/>RelativeLayout>效果图：
activity_book_list.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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=".BookListActivity"> <include android:id="@+id/include" layout="@layout/title" /> <ListView android:id="@+id/bookListView" android:layout_width="0dp" android:layout_height="0dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/include" />androidx.constraintlayout.widget.ConstraintLayout>效果图：
activity_book_add.xml
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.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=".BookAddActivity"> <include android:id="@+id/include2" layout="@layout/title" /> <LinearLayout android:id="@+id/linearLayout7" android:layout_width="0dp" android:layout_height="50dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/include2"> <TextView android:id="@+id/textView3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginLeft="20dp" android:text="书籍名称" android:textColor="#111111" android:textSize="16sp" /> <EditText android:id="@+id/et_name" android:layout_width="0dp" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:layout_marginRight="20dp" android:layout_weight="1" android:background="@null" android:ems="10" android:gravity="right|center_vertical" android:hint="请输入书籍名称" android:inputType="textPersonName" /> LinearLayout> <View android:id="@+id/view7" android:layout_width="0dp" android:layout_height="1dp" android:background="#dddddd" app:layout_constraintEnd_toEndOf="@+id/linearLayout7" app:layout_constraintStart_toStartOf="@+id/linearLayout7" app:layout_constraintTop_toBottomOf="@+id/linearLayout7" /> <LinearLayout android:id="@+id/linearLayout8" android:layout_width="0dp" android:layout_height="50dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/view7"> <TextView android:id="@+id/textView4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:text="出版时间" android:textColor="#111111" android:textSize="16sp" /> <EditText android:id="@+id/et_publishing" android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="20dp" android:layout_weight="1" android:background="@null" android:ems="10" android:gravity="right|center_vertical" android:hint="请输入出版时间" android:inputType="textPersonName" /> LinearLayout> <LinearLayout android:id="@+id/linearLayout9" android:layout_width="0dp" android:layout_height="50dp" android:orientation="horizontal" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/view8"> <TextView android:id="@+id/textView5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:text="书籍简介" android:textColor="#111111" android:textSize="16sp" /> <EditText android:id="@+id/et_intro" android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="20dp" android:layout_weight="1" android:background="@null" android:ems="10" android:gravity="right|center_vertical" android:hint="请输入书籍简介" android:inputType="textPersonName" /> LinearLayout> <View android:id="@+id/view8" android:layout_width="0dp" android:layout_height="1dp" android:background="#DDDDDD" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/linearLayout8" /> <View android:id="@+id/view9" android:layout_width="0dp" android:layout_height="1dp" android:background="#DDDDDD" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/linearLayout9" /> <Button android:id="@+id/button6" android:layout_width="0dp" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginLeft="20dp" android:layout_marginTop="80dp" android:layout_marginEnd="20dp" android:layout_marginRight="20dp" android:background="@drawable/btn_shape" android:onClick="addBook" android:text="保存" android:textColor="#FFFFFF" android:textSize="20sp" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/view9" />androidx.constraintlayout.widget.ConstraintLayout>效果图：
BookAddActivity.java
import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;import androidx.localbroadcastmanager.content.LocalBroadcastManager;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import org.json.JSONObject;import java.io.InputStream;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;public class BookAddActivity extends AppCompatActivity { private EditText et_name; private EditText et_publishing; private EditText et_intro; private Handler handler = new Handler(){ @Override public void handleMessage(@NonNull Message msg) { if("200".equals(msg.obj)) { // 提示保存成功 Toast.makeText(BookAddActivity.this, "书籍添加成功", Toast.LENGTH_SHORT).show(); // 发送广播 LocalBroadcastManager.getInstance(BookAddActivity.this).sendBroadcast(new Intent("day15.book.add")); // 关闭本界面 finish(); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_book_add); et_name = findViewById(R.id.et_name); et_publishing = findViewById(R.id.et_publishing); et_intro = findViewById(R.id.et_intro); // 隐藏右边按钮 findViewById(R.id.btn_edit).setVisibility(View.INVISIBLE); // 修改标题 TextView textView = findViewById(R.id.tv_title); textView.setText("书籍添加"); // 返回按钮 findViewById(R.id.btn_back).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); } /** * 保存书籍 * @param view */ public void addBook(View view) { final String name = et_name.getText().toString().trim(); final String publishing = et_publishing.getText().toString().trim(); final String intro = et_intro.getText().toString().trim(); // 发请求 new Thread(new Runnable() { @Override public void run() { HttpURLConnection connection = null; try { URL url = new URL("http://121.36.161.94:8080/book/addBook"); connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); // 准备参数并发送 String param = "name="+name+"&publishing="+publishing+"&intro="+intro; OutputStream out = connection.getOutputStream(); out.write(param.getBytes()); out.close(); // 处理返回结果 InputStream in = connection.getInputStream(); StringBuffer response = new StringBuffer(); int i = in.read(); while(i != -1) { response.append((char)i); i = in.read(); } JSONObject jsonObject = new JSONObject(response.toString()); Message message = new Message(); message.obj = jsonObject.getString("code"); handler.sendMessage(message); } catch (Exception e) { e.printStackTrace(); } } }).start(); }}BookListActivity.java
import androidx.appcompat.app.AppCompatActivity;import android.content.Intent;import android.os.Bundle;import android.view.View;public class BookListActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_book_list); // 跳转添加界面 findViewById(R.id.btn_edit).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { startActivity(new Intent(BookListActivity.this, BookAddActivity.class)); } }); // 返回事件 findViewById(R.id.btn_back).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); } }AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.day15"> <uses-permission android:name="android.permission.INTERNET" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/Theme.AppCompat.DayNight.NoActionBar" android:usesCleartextTraffic="true"> <activity android:name=".BookAddActivity">activity> <activity android:name=".BookListActivity" /> <activity android:name=".IndexActivity" /> <activity android:name=".RegisterActivity" /> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> intent-filter> activity> application>manifest>更多相关文章
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