android很多情況是使用webView用來顯示界面，但是webview的加載速度略慢，想讓這個webview更快一些所以需要使用緩存，在沒有更新的時候使用緩存技術來提高速度。總體來講有兩個方案可以實現這個內容。1.用本地文件js，css，png替換網絡請求下來的文件，2.直接使用webview的緩存。
第一種方法用本地文件js，css，png替換網絡請求下來的文件是在webview的setWebViewClient里面的shouldInterceptRequest方法用本地文件進行替換。
mWebView.setWebViewClient(new WebViewClient(){
@Override
public void onPageFinished(WebView webView, String s) {
super.onPageFinished(webView, s);
mWebView.getSettings().setBlockNetworkImage(false);
//加載完成時調用
}
//新加載WebView的方法
@Override
public boolean shouldOverrideUrlLoading(final WebView webView, final String url) {
Log.e("sys","url="+url);
//判斷url
if (!(url.startsWith("http") || url.startsWith("https"))) {
return true;
}
/**
* 推薦采用的新的二合一接口(payInterceptorWithUrl),只需調用一次
*/
final PayTask task = new PayTask(BaseWebActivity.this);
boolean isIntercepted = task.payInterceptorWithUrl(url, true, new H5PayCallback() {
@Override
public void onPayResult(final H5PayResultModel result) {
final String url=result.getReturnUrl();
Log.e("sys","url="+ url);
switch (result.getResultCode()) {
/*
9000——訂單支付成功
8000——正在處理中
4000——訂單支付失敗
5000——重復請求
6001——用戶中途取消
6002——網絡連接出錯
*/
case "4000":
webView.loadUrl("javascript:appCallJsShowOrder()");
Log.e("sys","4000");
break;
case "6001":
webView.loadUrl("javascript:appCallJsShowOrder()");
Log.e("sys","6001");
break;
case "6002":
webView.loadUrl("javascript:appCallJsShowOrder()");
Log.e("sys","6002");
break;
case "9000":
break;
}
}
}
});
/**
* 判斷是否成功攔截
* 若成功攔截，則無需繼續加載該URL；否則繼續加載
*/
if(!isIntercepted) {
Log.e("is","update");
webView.loadUrl(url);
}
return true;
}
//獲得下載列表
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
WebResourceResponse response = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
response = super.shouldInterceptRequest(view,url);
if (url.contains(".js")||url.contains(".png")||url.contains(".css")){
Log.e("fileUrl",url);
String[] arr = StrUtil.getStrArr(url,"/");
String jsFileName = arr[arr.length-1];
String[] arrEnd = StrUtil.getStrArr(jsFileName,"\\.");
if (arr.length!=0){
if(arrEnd.length != 0) {
Log.e("arr",jsFileName);
if(jsFileName.equals("fastclick.min.js")){
Log.e("fastclick","fastclick");
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("fastclick.min.js"));
} catch (IOException e) {
e.printStackTrace();
}
}
if(jsFileName.equals("geolocation.min.js")){
Log.e("geolocation","geolocation");
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("geolocation.min.js"));
} catch (IOException e) {
e.printStackTrace();
}
}
if(jsFileName.equals("g2.min.js")){
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("g2.min.js"));
} catch (IOException e) {
e.printStackTrace();
}
}
if(jsFileName.equals("login_bg.5563a40.png")){
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("login_bg.5563a40.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
if(jsFileName.equals("favicon-16x16.png")){
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("favicon-16x16.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
if(jsFileName.equals("favicon-32x32.png")){
try {
return new WebResourceResponse("application/x-javascript","utf-8",getBaseContext().getAssets().open("favicon-32x32.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
return response;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
WebResourceResponse response = null;
response = super.shouldInterceptRequest(view, request);
return response;
}
@Override
public void onReceivedError(final WebView webView, int i, String s, String s1) {
super.onReceivedError(webView, i, s, s1);
}
@Override
public void onReceivedError(WebView webView, WebResourceRequest webResourceRequest, WebResourceError webResourceError) {
super.onReceivedError(webView, webResourceRequest, webResourceError);
Log.e("sys","onReceivedError webResourceError");
}
});
2.首先設置webSetting設置成使用LOAD_DEFAULT這種緩存方式，數據從緩存中獲取還是從網絡中獲取根據H5頁面的參數判斷，這樣做的好處是可以動態的處理更新內容。再判斷版本是否清理緩存。
//設置webview屬性
private void initWebViewSettings() {
WebSettings webSetting = webView.getSettings();
webSetting.setJavaScriptEnabled(true);
webSetting.setJavaScriptCanOpenWindowsAutomatically(true);
webSetting.setAllowFileAccess(true);
webSetting.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
webSetting.setSupportZoom(true);
webSetting.setBuiltInZoomControls(true);
webSetting.setUseWideViewPort(true);
webSetting.setSupportMultipleWindows(true);
// webSetting.setLoadWithOverviewMode(true);
webSetting.setAppCacheEnabled(true);
// webSetting.setDatabaseEnabled(true);
webSetting.setDomStorageEnabled(true);
webSetting.setGeolocationEnabled(true);
webSetting.setDatabaseEnabled(true);
webSetting.setAppCacheMaxSize(Long.MAX_VALUE);
webSetting.setTextZoom(100);
webSetting.setBlockNetworkImage(true);
// webSetting.setPageCacheCapacity(IX5WebSettings.DEFAULT_CACHE_CAPACITY);
webSetting.setPluginState(WebSettings.PluginState.ON_DEMAND);
webSetting.setRenderPriority(WebSettings.RenderPriority.HIGH);
webSetting.setCacheMode(WebSettings.LOAD_DEFAULT);
String userAgent = webSetting.getUserAgentString().replace("Mobile","Snail");
webSetting.setUserAgentString(userAgent);
// this.getSettingsExtension().setPageCacheCapacity(IX5WebSettings.DEFAULT_CACHE_CAPACITY);//extension
// settings 的設計
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
if (this.mWebView != null) {
try
{
//在這里獲得版本號 清除緩存
if(version!=lastVersion){
mWebView.clearCache(true);
context.deleteDatabase("webview.db");//刪除數據庫緩存
context.deleteDatabase("webviewCache.db");
}
}
catch (Exception e) {
}
mWebView.destroy();
}
}