Question

我有一个PHP文件，当我运行它时，它会从数据库中获取所有员工，以JSON格式告诉所有员工。

Android Studio中的此代码通过php文件从数据库中获取所有员工

当我运行应用程序时，我无法在Android Studio中获取数据。

它返回此错误：

类型java.lang.String的值连接无法转换为JSONObject

图片中的

这是Android Studio中的Java代码：

package com.example.ibrahim.samplecrud;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;

public class ViewAllEmployee extends AppCompatActivity implements ListView.OnItemClickListener {

    private ListView listView;

    private String JSON_STRING;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_all_employee);
        listView = (ListView) findViewById(R.id.listView);
        listView.setOnItemClickListener(this);
        getJSON();
    }


    private void showEmployee(){
        JSONObject jsonObject = null;
        ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String, String>>();
        try {
            jsonObject = new JSONObject(JSON_STRING);
            JSONArray result = jsonObject.getJSONArray(Config.TAG_JSON_ARRAY);

            for(int i = 0; i<result.length(); i++){
                JSONObject jo = result.getJSONObject(i);
                String id = jo.getString(Config.TAG_ID);
                String name = jo.getString(Config.TAG_NAME);

                HashMap<String,String> employees = new HashMap<>();
                employees.put(Config.TAG_ID,id);
                employees.put(Config.TAG_NAME,name);
                list.add(employees);
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        ListAdapter adapter = new SimpleAdapter(
                ViewAllEmployee.this, list, R.layout.list_item,
                new String[]{Config.TAG_ID,Config.TAG_NAME},
                new int[]{R.id.id, R.id.name});

        listView.setAdapter(adapter);
    }

    private void getJSON(){
        class GetJSON extends AsyncTask<Void,Void,String>{

            ProgressDialog loading;
            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                loading = ProgressDialog.show(ViewAllEmployee.this,"Fetching Data","Wait...",false,false);
            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                loading.dismiss();
                JSON_STRING = s;
                showEmployee();
            }

            @Override
            protected String doInBackground(Void... params) {
                RequestHandler rh = new RequestHandler();
                String s = rh.sendGetRequest(Config.URL_GET_ALL);
                return s;
            }
        }
        GetJSON gj = new GetJSON();
        gj.execute();
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent = new Intent(this, ViewEmployee.class);
        HashMap<String,String> map =(HashMap)parent.getItemAtPosition(position);
        String empId = map.get(Config.TAG_ID).toString();
        intent.putExtra(Config.EMP_ID,empId);
        startActivity(intent);
    }
}

Answer 1

目前，从服务器接收的package com.web.viewers; import android.annotation.SuppressLint; import android.content.DialogInterface; import android.content.Intent; import android.graphics.Bitmap; import android.net.Uri; import android.os.Bundle; import android.support.v7.app.AlertDialog; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.webkit.WebResourceRequest; import android.webkit.WebView; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import com.daimajia.numberprogressbar.NumberProgressBar; public class MainActivity extends AppCompatActivity { private WebView webView; private String url = "http://www.myurl.com"; private NumberProgressBar progressBar; private String TAG = this.getClass().getSimpleName(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initializeWebView(); } @SuppressLint("SetJavaScriptEnabled") private void initializeWebView() { if (getIntent().getStringExtra("url") != null){ url = getIntent().getStringExtra("url"); } Log.d(TAG, "initializeWebView: " + url); webView = (WebView) findViewById(R.id.webView); webView.loadUrl(url); webView.getSettings().setJavaScriptEnabled(true); webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true); webView.setWebChromeClient(new WebChromeClient()); webView.setWebViewClient(new WebViewClient()); progressBar = (NumberProgressBar) findViewById(R.id.number_progress_bar); progressBar.setVisibility(View.GONE); } public class WebChromeClient extends android.webkit.WebChromeClient { @Override public void onProgressChanged(WebView view, int newProgress) { super.onProgressChanged(view, newProgress); progressBar.setProgress(newProgress); } } public class WebViewClient extends android.webkit.WebViewClient { @Override public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) { return super.shouldOverrideUrlLoading(view, request); } @Override public void onPageStarted(WebView view, String url, Bitmap favicon) { super.onPageStarted(view, url, favicon); progressBar.setVisibility(View.VISIBLE); } @Override public void onPageFinished(WebView view, String url) { super.onPageFinished(view, url); progressBar.setVisibility(View.GONE); } } @Override public void onBackPressed() { if (webView.canGoBack()){ webView.goBack(); } else { showAlertDialog(); } } private void showAlertDialog() { AlertDialog.Builder builder = new AlertDialog.Builder(this) .setMessage("Tutup Aplikasi ini ?") .setNegativeButton("Tidak", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { dialogInterface.dismiss(); } }) .setPositiveButton("Ya", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { dialogInterface.dismiss(); finish(); } }); AlertDialog dialog = builder.create(); dialog.show(); } }是

String

并且它不是有效的JSON格式

因此，您应该编辑服务器代码以返回正确的JSON格式，如

Connection sucessful{"result":[{"id":2,"name":A"},{"id","pop"},...]}

无法将类型为java.lang.String的值连接转换为JSONObject

1 个答案: