在Android上实现WiFi扫描器并仅列出特定SSID的网络，可以使用以下代码示例：

1. 在AndroidManifest.xml文件中添加以下权限：

2. 创建一个名为WifiScanner的类，并在其中添加以下代码：

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import java.util.ArrayList;
import java.util.List;

public class WifiScanner {

    private Context context;
    private WifiManager wifiManager;
    private WifiScanReceiver wifiScanReceiver;
    private List wifiSSIDs;

    public WifiScanner(Context context, List wifiSSIDs) {
        this.context = context;
        this.wifiSSIDs = wifiSSIDs;
        wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        wifiScanReceiver = new WifiScanReceiver();
    }

    public void startScanning() {
        context.registerReceiver(wifiScanReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
        wifiManager.startScan();
    }

    public void stopScanning() {
        context.unregisterReceiver(wifiScanReceiver);
    }

    private class WifiScanReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            List scanResults = wifiManager.getScanResults();
            List filteredScanResults = new ArrayList<>();

            for (ScanResult scanResult : scanResults) {
                if (wifiSSIDs.contains(scanResult.SSID)) {
                    filteredScanResults.add(scanResult);
                }
            }

            // 在这里处理筛选后的扫描结果
            for (ScanResult filteredScanResult : filteredScanResults) {
                String ssid = filteredScanResult.SSID;
                String bssid = filteredScanResult.BSSID;
                int signalStrength = filteredScanResult.level;
                // 其他处理代码...
            }
        }
    }
}

3. 在你的Activity或Fragment中使用WifiScanner类。例如，在你的MainActivity中：

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import java.util.Arrays;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private WifiScanner wifiScanner;
    private List wifiSSIDs = Arrays.asList("SSID1", "SSID2", "SSID3"); // 替换为你想要列出的特定SSID

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

        wifiScanner = new WifiScanner(this, wifiSSIDs);
        wifiScanner.startScanning();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        wifiScanner.stopScanning();
    }
}

这样，你将获得一个WiFi扫描器，它将仅列出特定SSID的网络，并且可以在MainActivity中的onReceive方法中对扫描结果进行处理。记得将"SSID1", "SSID2", "SSID3"替换为你想要列出的特定SSID。