android webview打開本地圖片上傳

Webview打開本地圖片選擇器十分之麻煩，其在安卓系統3x 4x 5x上的行爲都不同，處理也不同，所以之前差點崩潰。經過測試和完善，最終其在各個版本上都能完美工作。
直接上代碼

package com.testandroid.webview;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.JsResult;
import android.webkit.ValueCallback;
import android.webkit.WebBackForwardList;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;

import com.testandroid.R;

public class WebViewActivity extends AppCompatActivity {  

    private final String TAG = WebViewActivity.class.getSimpleName();

    private Button button;
    private WebView webView;

    private String recgPic = "http://m.shitu.chinaso.com/mx/index.html";

    public final static int FILECHOOSER_RESULTCODE = 1;
    public final static int FILECHOOSER_RESULTCODE_FOR_ANDROID_5 = 2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_web_view);

        button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            }
        });

        initTestWebView();

    }

    private void initTestWebView() {
        webView = (WebView) findViewById(R.id.tempWebView);

        WiewSettings settings = webView.getSettings();
        settings.setJavaScriptEnabled(true);

        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
                builder.setTitle("xxx提示").setMessage(message).setPositiveButton("確定", null);
                builder.setCancelable(false);
                builder.setIcon(R.mipmap.ic_launcher);
                AlertDialog dialog = builder.create();
                dialog.show();
                result.confirm();
                return true;
            }

            //擴展瀏覽器上傳文件
            //3.0++版本
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
                openFileChooserImpl(uploadMsg);
            }

            //3.0--版本
            public void openFileChooser(ValueCallback<Uri> uploadMsg) {
                openFileChooserImpl(uploadMsg);
            }

            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                openFileChooserImpl(uploadMsg);
            }

            @Override
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
                onenFileChooseImpleForAndroid(filePathCallback);
                return true;
            }
        });

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }
        });
        webView.loadUrl(recgPic);


    }

    public ValueCallback<Uri> mUploadMessage;
    private void openFileChooserImpl(ValueCallback<Uri> uploadMsg) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    public ValueCallback<Uri[]> mUploadMessageForAndroid5;
    private void onenFileChooseImpleForAndroid(ValueCallback<Uri[]> filePathCallback) {
        mUploadMessageForAndroid5 = filePathCallback;
        Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
        contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
        contentSelectionIntent.setType("image/*");

        Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
        chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
        chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");

        startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE_FOR_ANDROID_5);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode,Intent intent) {
        if (requestCode == FILECHOOSER_RESULTCODE) {
            if (null == mUploadMessage)
                return;
            Uri result = intent == null || resultCode != RESULT_OK ? null: intent.getData();
            mUploadMessage.onReceiveValue(result);
            mUploadMessage = null;

        } else if (requestCode == FILECHOOSER_RESULTCODE_FOR_ANDROID_5){
            if (null == mUploadMessageForAndroid5)
                return;
            Uri result = (intent == null || resultCode != RESULT_OK) ? null: intent.getData();
            if (result != null) {
                mUploadMessageForAndroid5.onReceiveValue(new Uri[]{result});
            } else {
                mUploadMessageForAndroid5.onReceiveValue(new Uri[]{});
            }
            mUploadMessageForAndroid5 = null;
        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (webView.canGoBack() && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
            //獲取歷史列表
            WebBackForwardList mWebBackForwardList = webView
                    .copyBackForwardList();
            //判斷當前歷史列表是否最頂端,其實canGoBack已經判斷過
            if (mWebBackForwardList.getCurrentIndex() > 0) {
                webView.goBack();
                return true;
            }
        }
        return super.onKeyDown(keyCode, event);
    }
}