本篇文章主要介绍了" Android 拦截WebView加载URL，控制其加载CSS、JS资源"，主要涉及到WebView,Exception,开发经验,请求方式,html代码方面的内容，对于CSSjrs看球网直播吧_低调看直播体育app软件下载_低调看体育直播感兴趣的同学可以参考一下：
绪论最近在项目中有了这样一个需求，我们都知道WebView加载网页可以缓存，但是web端想让客服端根据需求来缓存网页，也就是说web端在设置了http响应头，我...
class MyWebClient extends WebViewClient {
@OverridepublicbooleanshouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
returntrue;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@Overridepublic WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
if (!"get".equals(request.getMethod().toLowerCase())) {
returnsuper.shouldInterceptRequest(view, request);
}
String url = request.getUrl().toString();
//todo:计算url的hash
String md5URL = YUtils.md5(url);
//读取缓存的html页面
File file = new File(appCacheDir + File.separator + md5URL);
if (file.exists()) {
FileInputStream fileInputStream = null;
try {
fileInputStream = new FileInputStream(file);
Log.e(">>>>>>>>>", "读缓存");
returnnew WebResourceResponse(YUtils.readBlock(fileInputStream), YUtils.readBlock(fileInputStream), fileInputStream);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
returnnull;
}
try {
URL uri = new URL(url);
URLConnection connection = uri.openConnection();
InputStream uristream = connection.getInputStream();
String cache = connection.getHeaderField("Ddbuild-Cache");
String contentType = connection.getContentType();
//text/html; charset=utf-8
String mimeType = "";
String encoding = "";
if (contentType != null && !"".equals(contentType)) {
if (contentType.indexOf(";") != -1) {
String[] args = contentType.split(";");
mimeType = args[0];
String[] args2 = args[1].trim().split("=");
if (args.length == 2 && args2[0].trim().toLowerCase().equals("charset")) {
encoding = args2[1].trim();
} else {
encoding = "utf-8";
}
} else {
mimeType = contentType;
encoding = "utf-8";
}
}
if ("1".equals(cache)) {
//todo:缓存uristream
FileOutputStream output = new FileOutputStream(file);
int read_len;
byte[] buffer = newbyte[1024];
YUtils.writeBlock(output, mimeType);
YUtils.writeBlock(output, encoding);
while ((read_len = uristream.read(buffer)) > 0) {
output.write(buffer, 0, read_len);
}
output.close();
uristream.close();
FileInputStream fileInputStream = new FileInputStream(file);
YUtils.readBlock(fileInputStream);
YUtils.readBlock(fileInputStream);
Log.e(">>>>>>>>>", "读缓存");
returnnew WebResourceResponse(mimeType, encoding, fileInputStream);
} else {
Log.e(">>>>>>>>>", "网络加载");
returnnew WebResourceResponse(mimeType, encoding, uristream);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
returnnull;
}
}
//这里面读写操作比较多，还有截取那两个属性的字符串稍微有点麻烦/**
* int转byte
* by黄海杰 at：2015-10-29 16:15:06
* @param iSource
* @param iArrayLen
* @return
*/publicstaticbyte[] toByteArray(int iSource, int iArrayLen) {
byte[] bLocalArr = newbyte[iArrayLen];
for (int i = 0; (i < 4) && (i < iArrayLen); i++) {
bLocalArr[i] = (byte) (iSource >> 8 * i & 0xFF);
}
return bLocalArr;
}
/**
* byte转int
* by黄海杰 at：2015-10-29 16:14:37
* @param bRefArr
* @return
*/// 将byte数组bRefArr转为一个整数,字节数组的低位是整型的低字节位publicstaticinttoInt(byte[] bRefArr) {
int iOutcome = 0;
byte bLoop;
for (int i = 0; i < bRefArr.length; i++) {
bLoop = bRefArr[i];
iOutcome += (bLoop & 0xFF) << (8 * i);
}
return iOutcome;
}
/**
* 写入JS相关文件
* by黄海杰 at:2015-10-29 16:14:01
* @param output
* @param str
*/publicstaticvoidwriteBlock(OutputStream output, String str) {
try {
byte[] buffer = str.getBytes("utf-8");
int len = buffer.length;
byte[] len_buffer = toByteArray(len, 4);
output.write(len_buffer);
output.write(buffer);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 读取JS相关文件
* by黄海杰 at:2015-10-29 16:14:19
* @param input
* @return
*/publicstatic String readBlock(InputStream input) {
try {
byte[] len_buffer = newbyte[4];
input.read(len_buffer);
int len = toInt(len_buffer);
ByteArrayOutputStream output = new ByteArrayOutputStream();
int read_len = 0;
byte[] buffer = newbyte[len];
while ((read_len = input.read(buffer)) > 0) {
len -= read_len;
output.write(buffer, 0, read_len);
if (len <= 0) {
break;
}
}
buffer = output.toByteArray();
output.close();
returnnew String(buffer,"utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
returnnull;
}
//为了加密我们的html我们把url转成md5/**
* 字符串转MD5
* by黄海杰 at:2015-10-29 16:15:32
* @param string
* @return
*/publicstatic String md5(String string) {
byte[] hash;
try {
hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));
} catch (NoSuchAlgorithmException e) {
thrownew RuntimeException("Huh, MD5 should be supported?", e);
} catch (UnsupportedEncodingException e) {
thrownew RuntimeException("Huh, UTF-8 should be supported?", e);
}
StringBuilder hex = new StringBuilder(hash.length * 2);
for (byte b : hash) {
if ((b & 0xFF) < 0x10) hex.append("0");
hex.append(Integer.toHexString(b & 0xFF));
}
return hex.toString();
}
注意
