迟到总比没有好:)
下面的代码适用于大型几何体（至少对我而言）
哦，是的，这是简单 jsp 代理的代码
<%@page session="false"%>
<%@page import="java.net.*,java.io.*" %>
<%@page trimDirectiveWhitespaces="true"%>
<%
/**
* This is a white list proxy that could be used the prevent an error due to
* JavaScript Same Origin Policy.
*
* CAUTION: It might break some sites and it's a security risk because
* people can use this proxy to browse the web and possibly do bad and/or illegal stuff
* with it.
* It can load any content type.
* This proxy implementation was inspired by the proxy.cgi script of OpenLayers
* {@link http://openlayers.org}
* To use this in OpenLayers you have to set OpenLayers.ProxyHost = "Url/To/This/Proxyfile/proxy.jsp?";
* within your JavaScript code <br>
* The base code of the proxy has been provided by SNIPPLR
* {@link http://snipplr.com/view/17987/jsp-proxy-for-javascript-applications/}
*
* @author terrestris GmbH & Co. KG
* @author Christian Mayer
* @author Marc Jansen
*
* @license BSD see license.txt
*
*/
String[] allowedHosts = {
"www.openlayers.org", "openlayers.org",
"labs.metacarta.com", "world.freemap.in",
"prototype.openmnnd.org", "geo.openplans.org",
"sigma.openplans.org", "demo.opengeo.org",
"www.openstreetmap.org", "sample.azavea.com",
"v-swe.uni-muenster.de:8080",
"vmap0.tiles.osgeo.org",
"192.168.197.95:8080"
};
HttpURLConnection con = null;
try {
String reqUrl = request.getQueryString();
String decodedUrl = "";
if (reqUrl != null) {
reqUrl = URLDecoder.decode(reqUrl, "UTF-8");
}
else {
response.setStatus(400);
out.println("ERROR 400: No target specified for proxy.");
}
// extract the host
String host = "";
host = reqUrl.split("\\/")[2];
boolean allowed = false;
// check if host (with port) is in white list
for (String surl : allowedHosts) {
if (host.equalsIgnoreCase(surl)) {
allowed = true;
break;
}
}
// do the proxy action (load requested ressource and transport it to client)
// if host is in white list
if(allowed) {
// replace the white spaces with plus in URL
reqUrl = reqUrl.replaceAll(" ", "+");
// call the requested ressource
URL url = new URL(reqUrl);
con = (HttpURLConnection)url.openConnection();
con.setDoOutput(true);
con.setRequestMethod(request.getMethod());
String reqContenType = request.getContentType();
if(reqContenType != null) {
con.setRequestProperty("Content-Type", reqContenType);
}
else {
con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
}
int clength = request.getContentLength();
if(clength > 0) {
/* NOT WORKING FOR LARGE POST BODY
con.setDoInput(true);
byte[] idata = new byte[clength];
request.getInputStream().read(idata, 0, clength);
con.getOutputStream().write(idata, 0, clength);
*/
con.setDoInput(true);
InputStream istream = request.getInputStream();
OutputStream os = con.getOutputStream();
final int length = 5000;
byte[] bytes = new byte[length];
int bytesRead = 0;
while ((bytesRead = istream.read(bytes, 0, length)) > 0) {
os.write(bytes, 0, bytesRead);
}
}
// respond to client
response.setContentType(con.getContentType());
BufferedReader rd = new BufferedReader(new InputStreamReader(con.getInputStream()));
String line;
int i = 0;
while ((line = rd.readLine()) != null) {
out.println(line);
}
rd.close();
}
else {
// deny access via HTTP status code 502
response.setStatus(502);
out.println("ERROR 502: This proxy does not allow you to access that location.");
}
} catch(Exception e) {
// resond an internal server error with the stacktrace
// on exception
response.setStatus(500);
byte[] idata = new byte[5000];
if(con.getErrorStream() != null) {
con.getErrorStream().read(idata, 0, 5000);
}
out.println("ERROR 500: An internal server error occured. " + e.getMessage() + " " + new String(idata));
}
%>