Android WebView 快取機制和模式詳解
阿新 • • 發佈:2019-01-31
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); // 顯示載入介面 } @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); // 隱藏載入介面 } @Override public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { rl_loading.setVisibility(View.GONE); // 隱藏載入介面 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); //設定 快取模式 // 開啟 DOM storage API 功能 mWebView.getSettings().setDomStorageEnabled(true); //開啟 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); //設定資料庫快取路徑 mWebView.getSettings().setDatabasePath(cacheDirPath); //設定 Application Caches 快取目錄 mWebView.getSettings().setAppCachePath(cacheDirPath); //開啟 Application Caches 功能 mWebView.getSettings().setAppCacheEnabled(true); } /** * 清除WebView快取 */ public void clearWebViewCache(){ //清理Webview快取資料庫 try { deleteDatabase("webview.db"); deleteDatabase("webviewCache.db"); } catch (Exception e) { e.printStackTrace(); } //WebView 快取檔案 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()); //刪除webview 快取目錄 if(webviewCacheDir.exists()){ deleteFile(webviewCacheDir); } //刪除webview 快取 快取目錄 if(appCacheDir.exists()){ deleteFile(appCacheDir); } } /** * 遞迴刪除 檔案/資料夾 * * @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()); } } }