int size = webview.copyBackForwardList().getSize();
webview.goBackOrForward(size - 2*size);

public void goBackOrForward (int steps)

Go to the history item that is the number of steps away from the current item. Steps is negative if backward and positive if forward.
Parameters steps  The number of steps to take back or forward in the back forward list.

public static void savePicInfoToMediaStore(Context context,String originPath){
        File file = new File(originPath);
        ContentResolver contentResolver = context.getContentResolver();

        ContentValues newValues = new ContentValues(6);
        newValues.put(MediaStore.Images.Media.TITLE,
                file.getName());
        newValues.put(MediaStore.Images.Media.DISPLAY_NAME,
                file.getName());
        newValues.put(MediaStore.Images.Media.DATA, file.getPath());
        newValues.put(MediaStore.Images.Media.DATE_MODIFIED,
                System.currentTimeMillis() / 1000);
        newValues.put(MediaStore.Images.Media.SIZE, file.length());
        newValues.put(MediaStore.Images.Media.MIME_TYPE, "image/png");

        int i = contentResolver.update(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,newValues,MediaStore.Images.Media.DATA + " =?",new String[]{originPath});
        if(i == 0){//更新失败
            LogUtils.e("更新失败" + i + "保存图片信息");
            context.getContentResolver().insert(
                    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, newValues);
        }
     
        // 最后通知图库更新
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse(file.getParent())));
    }

webView.setWebViewClient(new WebViewClient() {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        HitTestResult hit = webView.getHitTestResult();
        int hitType = hit.getType();
        if (hitType == HitTestResult.SRC_ANCHOR_TYPE) {//点击超链接
	    //这里执行自定义的操作				
            return true;//返回true浏览器不再执行默认的操作
        }else if(hitType == 0){//重定向时hitType为0
            return false;//不捕获302重定向
        }else{
            return false;
        }
    }
});