Android安卓期末大作业-图书管理系统

package com.example.finalproject; import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.text.TextUtils; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ImageButton; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.example.finalproject.bean.Student; import com.example.finalproject.util.HideInputMethod; import com.example.finalproject.util.HttpURLConn; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * @author wunu */ @SuppressWarnings("all") public class studentList extends AppCompatActivity implements View.OnClickListener { private List<Student> allstudent; private ListView lv; private ImageButton ib_search; private Button bt_return; private EditText et_find; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_student_list); lv = findViewById(R.id.lv); et_find = findViewById(R.id.et_find); ib_search = findViewById(R.id.ib_search); ib_search.setOnClickListener(this); bt_return = findViewById(R.id.bt_return); bt_return.setOnClickListener(this); new Thread(new Runnable() { @Override public void run() { String url = HttpURLConn.BASE_URL + "/studentQuery"; Map<String, String> params = new HashMap<>(); params.put("key", ""); String result = HttpURLConn.getContextByHttp(url, params); Message message = new Message(); message.what = 0x11; Bundle data = new Bundle(); data.putString("result", result); // 测试能不能读取到结果 System.out.println(result); message.setData(data); handler.sendMessage(message); } }).start(); } private Handler handler = new Handler() { @Override public void handleMessage(@NonNull Message msg) { if (msg.what == 0x11) { // 每次查询都新建一个新的对象，不然会保留之前查询的值 allstudent = new ArrayList<>(); Bundle data = msg.getData(); String key = data.getString("result"); // 测试能不能读取到结果 System.out.println("key值为：=============" + key); try { JSONObject json = new JSONObject(key); // 获取JSONArray数组在指定位置的JSONObject对象 JSONArray listArray = json.getJSONArray("students"); // 测试能不能读取到结果 System.out.println("listArray========" + listArray); for (int i = 0; i < listArray.length(); i++) { // 获得数组中指定下标的JSON对象 JSONObject jsonObject = listArray.getJSONObject(i); String id = jsonObject.getString("id"); // 学号 String name = jsonObject.getString("name"); // 姓名 String major = jsonObject.getString("major"); // 专业 String isbn = jsonObject.getString("isbn"); // 书条码 Student student = new Student(id, name, major, isbn); allstudent.add(student); } // 显示查询结果 System.out.println("========================被调用了================="); lv.setAdapter(new MyAdapter()); } catch (JSONException e) { e.printStackTrace(); } } } }; /** * 进行查询操作 * * @param v */ @Override public void onClick(View v) { if (v.getId() == R.id.ib_search) { // 点击按钮后会自动隐藏软键盘 HideInputMethod.hideAllInputMethod(this); final String find = et_find.getText().toString().trim(); new Thread(new Runnable() { @Override public void run() { String url = HttpURLConn.BASE_URL + "/studentQuery"; Map<String, String> params = new HashMap<>(); params.put("key", find); String result = HttpURLConn.getContextByHttp(url, params); Message message = new Message(); message.what = 0x11; Bundle data = new Bundle(); data.putString("result", result); message.setData(data); handler.sendMessage(message); } }).start(); } else if (v.getId() == R.id.bt_return) { Intent intent = new Intent(); // 创建一个新意图 setResult(Activity.RESULT_OK, intent); // 携带意图返回前一个页面 finish(); // 关闭当前页面 } } private class MyAdapter extends BaseAdapter { @Override public int getCount() { return allstudent.size(); } @Override public View getView(int position, View convertView, ViewGroup parent) { View view = View.inflate(studentList.this, R.layout.select_item, null); TextView tv_id = view.findViewById(R.id.tv_id); TextView tv_name = view.findViewById(R.id.tv_name); TextView tv_major = view.findViewById(R.id.tv_major); TextView tv_isbn = view.findViewById(R.id.tv_isbn); tv_id.setText(allstudent.get(position).getId()); tv_name.setText(allstudent.get(position).getName()); tv_major.setText(allstudent.get(position).getMajor()); tv_isbn.setText(allstudent.get(position).getIsbn()); return view; } @Override public Object getItem(int position) { return null; } @Override public long getItemId(int position) { return 0; } } }