Android WebView 缓存处理

package com.example.webviewtest; 

   

import java.io.File; 

   

import android.app.Activity; 

import android.graphics.Bitmap; 

import android.os.Bundle; 

import android.util.Log; 

import android.view.View; 

import android.webkit.JsPromptResult; 

import android.webkit.JsResult; 

import android.webkit.WebChromeClient; 

import android.webkit.WebSettings; 

import android.webkit.WebSettings.RenderPriority; 

import android.webkit.WebView; 

import android.webkit.WebViewClient; 

import android.widget.RelativeLayout; 

import android.widget.TextView; 

import android.widget.Toast; 

   

public class MainActivity extends Activity { 

   

    private static final String TAG = MainActivity.class.getSimpleName(); 

    private static final String APP_CACAHE_DIRNAME = "/webcache"; 

    private TextView tv_topbar_title; 

    private RelativeLayout rl_loading; 

    private WebView mWebView; 

    private String url; 

   

    @Override 

    protected void onCreate(Bundle savedInstanceState) { 

        super.onCreate(savedInstanceState); 

        setContentView(R.layout.activity_main); 

           

        //url:http://m.dianhua.cn/detail/31ccb426119d3c9eaa794df686c58636121d38bc?apikey=jFaWGVHdFVhekZYWTBWV1ZHSkZOVlJWY&app=com.yulore.yellowsdk_ios&uid=355136051337627 

        url = "http://m.dianhua.cn/detail/31ccb426119d3c9eaa794df686c58636121d38bc?apikey=jFaWGVHdFVhekZYWTBWV1ZHSkZOVlJWY&app=com.yulore.yellowsdk_ios&uid=355136051337627"; 

        findView(); 

    } 

   

    private void findView() { 

           

        tv_topbar_title = (TextView) findViewById(R.id.tv_topbar_title); 

           

        rl_loading = (RelativeLayout) findViewById(R.id.rl_loading); 

           

        mWebView = (WebView) findViewById(R.id.mWebView); 

           

        initWebView(); 

           

        mWebView.setWebViewClient(new WebViewClient() { 

   

            @Override 

            public void onLoadResource(WebView view, String url) { 

                   

                Log.i(TAG, "onLoadResource url="+url); 

                   

                super.onLoadResource(view, url); 

            } 

   

            @Override 

            public boolean shouldOverrideUrlLoading(WebView webview, String url) { 

   

                Log.i(TAG, "intercept url="+url); 

                   

                webview.loadUrl(url); 

   

                return true; 

            } 

   

            @Override 

            public void onPageStarted(WebView view, String url, Bitmap favicon) { 

                   

                Log.e(TAG, "onPageStarted"); 

                   

                rl_loading.setVisibility(View.VISIBLE); // 显示加载界面 

            } 

   

            @Override 

            public void onPageFinished(WebView view, String url) { 

   

                String title = view.getTitle(); 

   

                Log.e(TAG, "onPageFinished WebView title=" + title); 

   

                tv_topbar_title.setText(title); 

                tv_topbar_title.setVisibility(View.VISIBLE); 

   

                rl_loading.setVisibility(View.GONE); // 隐藏加载界面 

            } 

   

            @Override 

            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { 

   

                rl_loading.setVisibility(View.GONE); // 隐藏加载界面 

   

                Toast.makeText(getApplicationContext(), "", 

                        Toast.LENGTH_LONG).show(); 

            } 

        }); 

   

        mWebView.setWebChromeClient(new WebChromeClient() { 

   

            @Override 

            public boolean onJsAlert(WebView view, String url, String message, JsResult result) { 

   

                Log.e(TAG, "onJsAlert " + message); 

   

                Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show(); 

   

                result.confirm(); 

   

                return true; 

            } 

   

            @Override 

            public boolean onJsConfirm(WebView view, String url, String message, JsResult result) { 

   

                Log.e(TAG, "onJsConfirm " + message); 

   

                return super.onJsConfirm(view, url, message, result); 

            } 

   

            @Override 

            public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, JsPromptResult result) { 

   

                Log.e(TAG, "onJsPrompt " + url); 

   

                return super.onJsPrompt(view, url, message, defaultValue, result); 

            } 

        }); 

           

        mWebView.loadUrl(url); 

    } 

   

    private void initWebView() { 

           

        mWebView.getSettings().setJavaScriptEnabled(true); 

        mWebView.getSettings().setRenderPriority(RenderPriority.HIGH); 

        mWebView.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);  //设置 缓存模式 

        // 开启 DOM storage API 功能 

        mWebView.getSettings().setDomStorageEnabled(true); 

        //开启 database storage API 功能 

        mWebView.getSettings().setDatabaseEnabled(true);  

        String cacheDirPath = getFilesDir().getAbsolutePath()+APP_CACAHE_DIRNAME; 

//      String cacheDirPath = getCacheDir().getAbsolutePath()+Constant.APP_DB_DIRNAME; 

        Log.i(TAG, "cacheDirPath="+cacheDirPath); 

        //设置数据库缓存路径 

        mWebView.getSettings().setDatabasePath(cacheDirPath); 

        //设置  Application Caches 缓存目录 

        mWebView.getSettings().setAppCachePath(cacheDirPath); 

        //开启 Application Caches 功能 

        mWebView.getSettings().setAppCacheEnabled(true); 

    } 

       

    /**

     * 清除WebView缓存

     */ 

    public void clearWebViewCache(){ 

           

        //清理Webview缓存数据库 

        try { 

            deleteDatabase("webview.db");  

            deleteDatabase("webviewCache.db"); 

        } catch (Exception e) { 

            e.printStackTrace(); 

        } 

           

        //WebView 缓存文件 

        File appCacheDir = new File(getFilesDir().getAbsolutePath()+APP_CACAHE_DIRNAME); 

        Log.e(TAG, "appCacheDir path="+appCacheDir.getAbsolutePath()); 

           

        File webviewCacheDir = new File(getCacheDir().getAbsolutePath()+"/webviewCache"); 

        Log.e(TAG, "webviewCacheDir path="+webviewCacheDir.getAbsolutePath()); 

           

        //删除webview 缓存目录 

        if(webviewCacheDir.exists()){ 

            deleteFile(webviewCacheDir); 

        } 

        //删除webview 缓存 缓存目录 

        if(appCacheDir.exists()){ 

            deleteFile(appCacheDir); 

        } 

    } 

       

    /**

     * 递归删除 文件/文件夹

     * 

     * @param file

     */ 

    public void deleteFile(File file) { 

   

        Log.i(TAG, "delete file path=" + file.getAbsolutePath()); 

           

        if (file.exists()) { 

            if (file.isFile()) { 

                file.delete(); 

            } else if (file.isDirectory()) { 

                File files[] = file.listFiles(); 

                for (int i = 0; i < files.length; i++) { 

                    deleteFile(files[i]); 

                } 

            } 

            file.delete(); 

        } else { 

            Log.e(TAG, "delete file no exists " + file.getAbsolutePath()); 

        } 

    } 

   

}