Android 显示 WebView ，加载URL 时，向webview的 header 里面传递参数

1、主要布局 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context=".MainActivity">

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </WebView>

</RelativeLayout>

2、代码实现

package com.webview.demo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.webkit.WebView;

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {

    private WebView webView ;

    private String webViewHeaderKey = "tokenId" ;
    private String webViewHeaderValue = "562142" ;

    private String url = "" ;

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

        webView = (WebView) findViewById( R.id.webview );


        if ( webViewHeaderValue != "" ){
            Map<String, String > map = new HashMap<String, String>() ;
            map.put( webViewHeaderKey , webViewHeaderValue ) ;

            webView.loadUrl( url  , map ) ;
        }else {
            webView.loadUrl( url ) ;
        }

    }
}