Okhttp session持久化

先看看HttpEngine中的代码

private Request networkRequest(Request request) throws IOException {
Request.Builder result = request.newBuilder();

if (request.header("Host") == null) {  result.header("Host", hostHeader(request.url(), false));}if (request.header("Connection") == null) {  result.header("Connection", "Keep-Alive");}if (request.header("Accept-Encoding") == null) {  transparentGzip = true;  result.header("Accept-Encoding", "gzip");}List<Cookie> cookies = client.cookieJar().loadForRequest(request.url());if (!cookies.isEmpty()) {  result.header("Cookie", cookieHeader(cookies));}if (request.header("User-Agent") == null) {  result.header("User-Agent", Version.userAgent());}return result.build();

}

/* Returns a ‘Cookie’ HTTP request header with all cookies, like {@code a=b; c=d}. /
private String cookieHeader(List cookies) {
StringBuilder cookieHeader = new StringBuilder();
for (int i = 0, size = cookies.size(); i < size; i++) {
if (i > 0) {
cookieHeader.append(“; “);
}
Cookie cookie = cookies.get(i);
cookieHeader.append(cookie.name()).append(‘=’).append(cookie.value());
}
return cookieHeader.toString();
}
从中可以看到我们这从client.cookieJar().loadForRequest(request.url());获取cookie，然后再为header设置cookie-> result.header(“Cookie”, cookieHeader(cookies));
而在cookieHeader()方法中主要实现了name=values;的形式。所以loadForRequest()方法比较重要了。也就是在每次请求的时候，我们都会通过CookieJar为请求头添加cookie。

接下来我们看看接收的时候：
public void receiveHeaders(Headers headers) throws IOException {
if (client.cookieJar() == CookieJar.NO_COOKIES) return;

List<Cookie> cookies = Cookie.parseAll(userRequest.url(), headers);if (cookies.isEmpty()) return;client.cookieJar().saveFromResponse(userRequest.url(), cookies);

}
也就是通过saveFromResponse()方法存储cookie。

所以小结一下，在发送时通过client.cookieJar().loadForRequest()添加cookie，在接收的时候通过client.cookieJar().saveFromResponse(）保存cookie。所以这两个方法很重要。