Android WebView删除缓存

1. 删除保存于手机上的缓存

// clear the cache before time numDays     
private int clearCacheFolder(File dir, long numDays) {          
    int deletedFiles = 0;         
    if (dir!= null && dir.isDirectory()) {             
        try {                
            for (File child:dir.listFiles()) {    
                if (child.isDirectory()) {              
                    deletedFiles += clearCacheFolder(child, numDays);          
                }    
                if (child.lastModified() < numDays) {     
                    if (child.delete()) {                   
                        deletedFiles++;           
                    }    
                }    
            }             
        } catch(Exception e) {       
            e.printStackTrace();    
        }     
    }       
    return deletedFiles;     
}

activity中的代码：

webView.clearCache(true);
clearCacheFolder(getApplicationContext().getCacheDir(),
System.currentTimeMillis());
getApplicationContext().deleteDatabase("webview.db");
getApplicationContext().deleteDatabase("webviewCache.db");
clearCacheFolder(getApplicationContext().getCacheDir(),
System.currentTimeMillis());
getApplicationContext().deleteDatabase("webview.db");
getApplicationContext().deleteDatabase("webviewCache.db");

//优先使用缓存：
WebView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);      
//不使用缓存：    
WebView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);

File file = CacheManager.getCacheFileBaseDir();      
   if(file != null && file.exists() && file.isDirectory()) {      
    for(File item : file.listFiles()) {      
     item.delete();      
    }      
    file.delete();      
   }      
  context.deleteDatabase("webview.db");      
  context.deleteDatabase("webviewCache.db");