实际工作中，需要在内网访问外网，安卓端webview能够显示外网页面。实现方式是公司内网假设了代理服务器，可以转发到外网。可是安卓webview不支持配置代理的功能。所以最终的方案是，webview访问内网的一个后台服务器，后台服务器经过加工代理，最终返回给webview网页页面。
这里的后台服务器，就是用springboot的拦截器实现的，对所有访问该服务器的接口都拦截、代理处理。
比如要真实访问的地址是：https://www.baidu.com
java代理服务器的地址是: http://192.168.110.41:8080 （就是本文自己的服务器部署的地址）
那么webview要加载的url为： http://192.168.110.41:8080/https://www.baidu.com
1、拦截器BootInterceptor 的配置
@Slf4j
public class BootInterceptor implements HandlerInterceptor {
private String host;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
URI uri = new URI(request.getRequestURI());
String path = uri.getPath().substring(1);
String query = request.getQueryString();
if (!StringUtils.isEmpty(query)) {
path = path + "?" + query;
}
log.info("BootInterceptor path==>" + path);
if (path.startsWith("http:") || path.startsWith("https:")) {
int index = path.indexOf("/", 10);
host = path.substring(0, index);
} else {
path = host + "/" + path;
}
log.info("BootInterceptor final path==>" + path);
String subHost="";
if (host.startsWith("http://")){
subHost=host.substring("http://".length());
}else if (host.startsWith("https://")){
subHost=host.substring("https://".length());
}
ProxyUtils2.Proxy(request, response, path,subHost);
return false;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
}
@Configuration
public class BootConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new BootInterceptor()).addPathPatterns("/**");
}
}
2、代理的工具类
ProxyUtils
public class ProxyUtils {
public static final String ip = "192.168.120.50"; // 代理主机地址（公司的硬件代理服务器地址，外网出口服务器）
public static final int port = 8000; // 代理主机端口
public static void Proxy(HttpServletRequest request, HttpServletResponse response, String url, String host) throws Exception {
URI newUri = new URI(url);
// 执行代理查询
String methodName = request.getMethod();
HttpMethod httpMethod = HttpMethod.resolve(methodName);
if (httpMethod == null) {
return;
}
SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
factory.setProxy(new java.net.Proxy(Proxy.Type.HTTP, new InetSocketAddress(ip, port)));
ClientHttpRequest delegate = factory.createRequest(newUri, httpMethod);
Enumeration<String> headerNames = request.getHeaderNames();
// 设置请求头
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
Enumeration<String> v = request.getHeaders(headerName);
List<String> arr = new ArrayList<>();
while (v.hasMoreElements()) {
arr.add(v.nextElement());
}
if ("host".equals(headerName)) {
delegate.getHeaders().add("host", host);
} else {
delegate.getHeaders().addAll(headerName, arr);
}
}
StreamUtils.copy(request.getInputStream(), delegate.getBody());
try {
// 执行远程调用
ClientHttpResponse clientHttpResponse = delegate.execute();
response.setStatus(clientHttpResponse.getStatusCode().value());
// 设置响应头
clientHttpResponse.getHeaders().forEach((key, value) -> value.forEach(it -> {
response.setHeader(key, it);
}));
StreamUtils.copy(clientHttpResponse.getBody(), response.getOutputStream());
} catch (Exception exception) {
//测试重定向的代码
response.setStatus(302);
response.addHeader("Location", "https://www.sohu.com/a/339180879_100024181");
}
}
}
ProxyUtils2
@Slf4j
public class ProxyUtils2 {
public static final String ip = "192.168.120.50"; // 代理主机地址（公司的硬件代理服务器地址，外网出口服务器）
public static final int port = 8000; // 代理主机端口
public static void Proxy(HttpServletRequest httpServletRequest,
HttpServletResponse httpServletResponse,
String url, String host) throws Exception {
OkHttpClient httpClient = getHttpClient(ip, port);
Enumeration<String> headerNames = httpServletRequest.getHeaderNames();
// 设置请求头
Headers.Builder headerBuilder = new Headers.Builder();
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
Enumeration<String> v = httpServletRequest.getHeaders(headerName);
StringBuffer arr = new StringBuffer();
while (v.hasMoreElements()) {
arr.append(v.nextElement());
}
if ("host".equals(headerName)){
headerBuilder.add("host",host);
}else {
headerBuilder.add(headerName, arr.toString());
}
}
Request request = new Request.Builder()
.get()
.headers(headerBuilder.build())
.url(url)
.build();
log.info("test request headers==>" + request.headers().toString());
// StreamUtils.copy(httpServletRequest.getInputStream(), request.body());
// 执行远程调用
Response response = httpClient.newCall(request).execute();
httpServletResponse.setStatus(response.code());
// 设置响应头
Headers headers = response.headers();
for (int i=0;i<headers.size();i++){
String name = headers.name(i);
String value = headers.value(i);
httpServletResponse.setHeader(name, value);
}
assert response.body() != null;
StreamUtils.copy(response.body().byteStream(), httpServletResponse.getOutputStream());
log.info("test response Status==>" + response.code());
log.info("test response headers==>" + headers.toString());
// log.info("test response body==>" + response.body().string());
}
private static OkHttpClient getHttpClient(String proxyHost, int proxyPort) {
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));
OkHttpClient build = new OkHttpClient.Builder()
.proxy(proxy)
.connectTimeout(180, TimeUnit.SECONDS)
.readTimeout(180, TimeUnit.SECONDS)
.writeTimeout(180, TimeUnit.SECONDS)
.retryOnConnectionFailure(true)
.sslSocketFactory(createSSLSocketFactory())
.hostnameVerifier(new TrustAllHostnameVerifier())
.followRedirects(false) //禁制OkHttp的重定向操作，我们自己处理重定向 设置为false时关闭重定向自动处理
.followSslRedirects(false)
.build();
return build;
}
private static class TrustAllHostnameVerifier implements HostnameVerifier {
public boolean verify(String hostname, SSLSession session) {
return true;
}
}
private static SSLSocketFactory createSSLSocketFactory() {
SSLSocketFactory ssfFactory = null;
try {
SSLContext sc = SSLContext.getInstance("TLS");
sc.init(null, new TrustManager[]{new TrustAllCerts()}, new SecureRandom());
ssfFactory = sc.getSocketFactory();
} catch (Exception e) {
}
return ssfFactory;
}
private static class TrustAllCerts implements X509TrustManager {
public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
}
public X509Certificate[] getAcceptedIssuers() {
return new X509Certificate[0];
}
}
}
3、另外，本文还提供一个代理服务器的写法，支持文件上传等功能
@Controller
public class ProxyController{
// 内网服务器地址+端口
private String targetAddr = "https://www.baidu.com/";
private String proxyaAddr = "http://10.0.0.100:9000";
/**
* 代理所有请求
*
* @param request
* @param response
* @throws Exception
*/
@RequestMapping(value = "/proxy/**", method= RequestMethod.POST)
public void proxy(HttpServletRequest request, HttpServletResponse response) throws IOException, URISyntaxException {
// String url = URLDecoder.decode(request.getRequestURL().toString(), "UTF-8");
URI uri = new URI(request.getRequestURI());
String path = uri.getPath();
String query = request.getQueryString();
String target = targetAddr + path.replace("/proxy", "");
if (query != null && !query.equals("") && !query.equals("null")) {
target = target + "?" + query;
}
URI newUri = new URI(target);
// 执行代理查询
String methodName = request.getMethod();
HttpMethod httpMethod = HttpMethod.resolve(methodName);
if (httpMethod == null) {
return;
}
InputStream stream = null;
String contentType = request.getContentType();
// 兼容文件上传的请求
if (contentType != null && contentType.startsWith("multipart/form-data")){
MultipartHttpServletRequest mulReq = (MultipartHttpServletRequest) request;
Map<String, MultipartFile> map = mulReq.getFileMap();
List<MultipartFile> valueList = new ArrayList<MultipartFile>(map.values());
MultiValueMap<String, Object> params = new LinkedMultiValueMap();
for (MultipartFile file : valueList) {
File newFile = File.createTempFile("temp",file.getOriginalFilename());
FileUtils.copyInputStreamToFile(file.getInputStream(), newFile);
FileSystemResource resource = new FileSystemResource(newFile);
params.add(file.getName(), resource);
}
RestTemplate restTemplate = new RestTemplate();
// 设置请求头
HttpHeaders headers = new HttpHeaders();
Enumeration<String> headerNames = request.getHeaderNames();
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
System.out.println(headerName + ":" + request.getHeader(headerName));
headers.set(headerName,request.getHeader(headerName));
}
// 手动设置请求头的token信息
headers.set("Authorization",request.getHeader("Authorization"));
// 用HttpEntity封装整个请求报文
HttpEntity<MultiValueMap<String, Object>> files = new HttpEntity<MultiValueMap<String, Object>>(params,headers);
String res = restTemplate.postForEntity(target, files, String.class).getBody();
InputStream is =new ByteArrayInputStream(res.getBytes("UTF-8"));
stream = is;
// 其他请求例如get post put delete都可使用
}else {
ClientHttpRequest delegate = new SimpleClientHttpRequestFactory().createRequest(newUri, httpMethod);
Enumeration<String> headerNames = request.getHeaderNames();
// 设置请求头
while (headerNames.hasMoreElements()) {
String headerName = headerNames.nextElement();
Enumeration<String> v = request.getHeaders(headerName);
List<String> arr = new ArrayList<>();
while (v.hasMoreElements()) {
arr.add(v.nextElement());
}
delegate.getHeaders().addAll(headerName, arr);
}
StreamUtils.copy(request.getInputStream(), delegate.getBody());
// 执行远程调用
ClientHttpResponse clientHttpResponse = delegate.execute();
response.setStatus(clientHttpResponse.getStatusCode().value());
// 设置响应头
clientHttpResponse.getHeaders().forEach((key, value) -> value.forEach(it -> {
response.setHeader(key, it);
}));
stream = clientHttpResponse.getBody();
}
// 将获取到的输入流再次输出到页面输出流中
StreamUtils.copy(stream, response.getOutputStream());
}
}
