Android获取清单文件中的meta-data,解决碰到数值为null的问题

    ActivityInfo info = null;
    try {
      info = this.getPackageManager().getActivityInfo(getComponentName(), PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
      e.printStackTrace();
    }
    info.metaData.getString("meta_name");

ApplicationInfo appInfo = null;
    try {
      appInfo = this.getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
      e.printStackTrace();
    }
    appInfo.metaData.getString("meta_name");

ComponentName cn = new ComponentName(this, XXXXService.class);
    ServiceInfo info = null;
    try {
      info = this.getPackageManager().getServiceInfo(cn, PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
      e.printStackTrace();
    }
    info.metaData.getString("meta_name");

ComponentName cn = new ComponentName(getApplicationContext(), XXXXXReceiver.class);
    ActivityInfo info = null;
    try {
      info = getApplicationContext().getPackageManager().getReceiverInfo(cn, PackageManager.GET_META_DATA);
    } catch (PackageManager.NameNotFoundException e) {
      e.printStackTrace();
    }
    info.metaData.getString("meta_name");

package com.dxgame.demo;

import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.util.Log;
import android.webkit.MimeTypeMap;
import android.webkit.WebResourceRequest;
import android.webkit.WebResourceResponse;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import java.io.InputStream;
import java.util.HashMap;

public class CheckLocal extends AppCompatActivity {

  private WebView webView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.check_local);
    webView.setWebViewClient(webViewClient);
  }


  //WebViewClient主要帮助WebView处理各种通知、请求事件
  private WebViewClient webViewClient = new WebViewClient() {

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
      Uri uri = request.getUrl();
      WebResourceResponse response = checkLocalWebResourceResponse(uri);
      if (response != null) {
        return response;
      }
      return super.shouldInterceptRequest(view, request);
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
      Uri uri = Uri.parse(url);
      WebResourceResponse response = checkLocalWebResourceResponse(uri);
      if (response != null) {
        return response;
      }
      return super.shouldInterceptRequest(view, url);
    }
  };

  @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
  private WebResourceResponse checkLocalWebResourceResponse(Uri uri) {
    WebResourceResponse resourceResponse = null;
    String urlStr = uri.toString();
    Log.i("checkUrl", urlStr);
    String path = uri.getPath();
    if (!TextUtils.isEmpty(path)) {
      path = path.substring(1);
    }
    try {
      InputStream input = getAssets().open(path);
      if (input != null) {
        Log.i("assetsPath", path);
        String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(path.substring(path.lastIndexOf(".") + 1));
        HashMap<String, String> header = new HashMap<>();
        header.put("Access-Control-Allow-Origin", "*");
        header.put("Access-Control-Allow-Headers", "Content-Type");
        resourceResponse = new WebResourceResponse(mimeType, "", 200, "ok", header, input);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
   return resourceResponse;
}