java – Android webview cookie返回null

发布时间：2020-12-14 05:52:27 所属栏目：Java 来源：网络整理

导读：我想在 android中的webview中设置和检索一个cookie.我已经尝试了许多cookie管理器脚本来尝试让它工作.我启用了 JavaScript. 在Samsung S3和Samsung Galaxy Tab 10.1上运行应用程序时,似乎根本没有设置cookie(android 4.1).但是,当在三星Galaxy ace,HTC Desir

我想在 android中的webview中设置和检索一个cookie.我已经尝试了许多cookie管理器脚本来尝试让它工作.我启用了 JavaScript.

在Samsung S3和Samsung Galaxy Tab 10.1上运行应用程序时,似乎根本没有设置cookie(android 4.1).但是,当在三星Galaxy ace,HTC Desire Z和Android模拟器上运行软件时,cookie被设置并读取完全正常.

工作时,webview按预期返回字符串,当不工作时,输出只是“null”; cookie没有值/没有设置.

我的具体情况也使用了滑动导航类,它是Actionbar Sherlock的扩展.

我真的很感激任何帮助,我几周来一直在努力解决这个问题.
谢谢.

HTML：

<html>
<head>
    <title>
    </title>
<script>
    function createCookie(name,value) 
    {
            var day  = (1 * 24 * 60 * 60 * 1000);
            var date = new Date();
            date.setTime(date.getTime() + (20 * 365 * day));
            var expires = "; expires=" + date.toGMTString();

            document.cookie = name + '=; expires=Thu,01 Jan 1970 00:00:01 GMT;';
            document.cookie = name + "=" + value + expires + "; path=/";
    }

    function readCookie(name) 
    {
        var nameEQ = name + "=";
        var ca = document.cookie.split(';');
        for(var i=0;i < ca.length;i++) {
            var c = ca[i];
            while (c.charAt(0)==' ') c = c.substring(1,c.length);
            if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
        }
        return null;
    }

</script>
</head>
<body>
<h1 class="">
<script type="text/javascript">
    createCookie("test","If this is working,it returns this string. If this is not working,it returns null.");
    document.write("test: " + readCookie("test"));
</script>
</body>
</html>

Java代码：

公共类MainActivity扩展SherlockActivity实现ISideNavigationCallback {

public static final String EXTRA_TITLE = "com.devspark.sidenavigation.sample.extra.MTGOBJECT";
public static final String EXTRA_RESOURCE_ID = "com.devspark.sidenavigation.sample.extra.RESOURCE_ID";
public static final String EXTRA_MODE = "com.devspark.sidenavigation.sample.extra.MODE";
public static String WebLoaded = "0";
public static String page = "signup.php";

private ImageView icon;
private SideNavigationView sideNavigationView;
private WebView engine;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    icon = (ImageView) findViewById(android.R.id.icon);
    sideNavigationView = (SideNavigationView) findViewById(R.id.side_navigation_view);
    sideNavigationView.setMenuItems(R.menu.side_navigation_menu);
    sideNavigationView.setMenuClickCallback(this);

    if (getIntent().hasExtra(EXTRA_TITLE)) {
        String title = getIntent().getStringExtra(EXTRA_TITLE);
        int resId = getIntent().getIntExtra(EXTRA_RESOURCE_ID,0);
        setTitle(title);
        icon.setImageResource(resId);
        sideNavigationView.setMode(getIntent().getIntExtra(EXTRA_MODE,0) == 0 ? Mode.LEFT : Mode.RIGHT);
    }

   //test
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    String domain = "localhost";

    CookieManager cookieManager = CookieManager.getInstance();
    cookieManager.setAcceptCookie(true);
    cookieManager.setCookie(domain,"name=value");
    cookieManager.setCookie(domain,"path=/");
    cookieManager.setCookie(domain,"HttpOnly");

    //enable cookies
    CookieManager.getInstance().setAcceptCookie(true);
    //navigates web engine,including on nav click
    engine = (WebView) findViewById(R.id.web_engine);  


    engine.loadUrl("file:///android_asset/" + page);
    //enable JavaScript support - disabled by default for some weird reason
    engine.getSettings().setJavaScriptEnabled(true);  
    engine.setWebViewClient(new WebViewClient());        






    //disables text selection
    engine.setOnLongClickListener(new View.OnLongClickListener() {
        public boolean onLongClick(View v) {
            return true;
        }
    });     
}

@Override
public void onPause()
{
    super.onPause();
    engine.getSettings().setJavaScriptEnabled(false);
}

@Override
public void onResume()
{
    super.onResume();
    engine.getSettings().setJavaScriptEnabled(true);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            sideNavigationView.toggleMenu();
            break;
        case R.id.mode_left:
            item.setChecked(true);
            sideNavigationView.setMode(Mode.LEFT);
            break;
        case R.id.mode_right:
            item.setChecked(true);
            sideNavigationView.setMode(Mode.RIGHT);
            break;

        default:
            return super.onOptionsItemSelected(item);
    }
    return true;
}

@Override
public void onSideNavigationItemClick(int itemId) {


    switch (itemId) {
        case R.id.side_navigation_menu_item1:
            invokeActivity(getString(R.string.title1),R.drawable.ic_android1);     
            page = "index.html";
            break;

        case R.id.side_navigation_menu_item2:
            invokeActivity(getString(R.string.title2),R.drawable.ic_android2);
            page = "test.html";
            break;

        case R.id.side_navigation_menu_item3:
            invokeActivity(getString(R.string.title3),R.drawable.ic_android3);
            break;

        case R.id.side_navigation_menu_item4:
            invokeActivity(getString(R.string.title4),R.drawable.ic_android4);
            break;

        case R.id.side_navigation_menu_item5:
            invokeActivity(getString(R.string.title5),R.drawable.ic_android5);
            break;

        default:
            return;
    }
    finish();
}

解决方法

经过一个多月的研究,我得出结论,在webview中设置一个大于2.3的安卓的cookie是不可能的,因为webview文件在localhost上(直接从assets文件夹中读取).

我经历了许多使用cookie存储的替代方案,包括使用HTML的本地存储.我被引导相信,这里的整个问题是安全问题.如果我要在localhost上创建cookie或localstorage,那么其他应用程序可以访问该存储,因此是一个主要的安全威胁.

我的最终问题是尝试通过与Java的双向通信来桥接webview,并且还有一个在此过程中存储数据的地方.我的解决方案是利用JavascriptInterface

这个想法如下：

>解析数据以在javascript中运行
> Javascript调用特殊的javascript函数,例如“setData(myDataName,myData)”
> Java有一个侦听它的函数,它将接受javscript设置的参数,并且还可以将值返回给javascript.
>将数据解析为Java后,java会将其存储在资产中的一系列文件中.
>当调用javascript函数“getData(myDataName)”时,Java会使用相同类型的方法返回数据.

我发现这非常有用：Android JavascriptInterface Documentation,Handling JavascriptInterface in Android 2.3

我发现的唯一主要“挂机”是Android 2.3中的fairly serious bug(固定在3.0),它有效地打破了JavascriptInterface.上面的第二个链接描述了我找到的最佳解决方法.

这是一个如何使双向通信工作的例子(它非常混乱,但它有效)：

自定义Web接口类：

public class webViewInterface { 
    //@JavascriptInterface //for SDK 12+
    public String showToast(String myText) {
        Toast.makeText(context,myText,Toast.LENGTH_LONG).show();
        return myText;
    }
    }

主要课程：
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

engine = (WebView) findViewById(R.id.web_engine); 

context = this;
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);

engine.setWebViewClient(new WebViewClient());
engine.loadUrl("file:///android_asset/" + page);

boolean javascriptInterfaceBroken = false;
try {
        if (Build.VERSION.RELEASE.startsWith("2.3")) {
         javascriptInterfaceBroken = true;
        }
    } catch (Exception e) {

    // Ignore,and assume user javascript interface is working correctly.
    }

// Add javascript interface only if it's not broken
    // @TODO: write the workaround for < 2.3 devices
if (!javascriptInterfaceBroken) {
        engine.addJavascriptInterface(new webViewInterface(),"MainActivityInterface");
}   

//disables text selection
engine.setOnLongClickListener(new View.OnLongClickListener() {
    public boolean onLongClick(View v) {
        return true;
    }
});     
}

HTML：

<html>
<head>
</head>
<body>

<input type="button" value="Say hello" onClick="showAndroidToast();" />

<script type="text/javascript">
    function showAndroidToast() {
        document.write(MainActivityInterface.showToast("eureka!"));
    }
</script>

</body>
</html>

（编辑：李大同）

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