package com.fasterxml.clustermate.service.servlet;
import java.io.IOException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.fasterxml.clustermate.service.ServiceResponse;
import com.fasterxml.clustermate.service.SharedServiceStuff;
import com.fasterxml.clustermate.service.cluster.ClusterViewByServer;
import com.fasterxml.storemate.shared.TimeMaster;
import com.fasterxml.storemate.store.util.OperationDiagnostics;
@SuppressWarnings("serial")
public class ServletBase extends HttpServlet
{
protected final Logger LOG = LoggerFactory.getLogger(getClass());
protected final TimeMaster _timeMaster;
protected final ClusterViewByServer _clusterView;
protected final String _basePath;
/**
* @param clusterView Handler to cluster information; needed to
* handling piggy-backed cluster state information
* @param servletPathBase (optional) Server base path that is to
* be ignored when matching request paths: if null, uses
* method <code>getServletPath</code> of <code>HttpServletRequest</code>.
*/
protected ServletBase(SharedServiceStuff stuff, ClusterViewByServer clusterView,
String servletPathBase)
{
_timeMaster = stuff.getTimeMaster();
_clusterView = clusterView;
if (servletPathBase != null) {
/* One tweak: ensure that base path ends with slash, to ensure
* we are not left with leading slash in path passed.
* Except in case of empty base.
*/
if (!servletPathBase.endsWith("/") && servletPathBase.length() > 0) {
servletPathBase += "/";
}
}
_basePath = servletPathBase;
}
protected ClusterViewByServer getClusterView() { return _clusterView; }
/*
/**********************************************************************
/* REST operation end points
/**********************************************************************
*/
@Override
public final void doGet(HttpServletRequest req0, HttpServletResponse resp0) throws IOException
{
handleGet(constructRequest(req0), constructResponse(resp0), constructMetadata());
}
@Override
public final void doHead(HttpServletRequest req0, HttpServletResponse resp0) throws IOException
{
handleHead(constructRequest(req0), constructResponse(resp0), constructMetadata());
}
@Override
public final void doPost(HttpServletRequest req0, HttpServletResponse resp0) throws IOException
{
handlePost(constructRequest(req0), constructResponse(resp0), constructMetadata());
}
@Override
public final void doPut(HttpServletRequest req0, HttpServletResponse resp0) throws IOException
{
handlePut(constructRequest(req0), constructResponse(resp0), constructMetadata());
}
@Override
public final void doDelete(HttpServletRequest req0, HttpServletResponse resp0) throws IOException
{
handleDelete(constructRequest(req0), constructResponse(resp0), constructMetadata());
}
/*
/**********************************************************************
/* Overridable methods
/**********************************************************************
*/
public void handleGet(ServletServiceRequest request, ServletServiceResponse response,
OperationDiagnostics stats)
throws IOException
{
response = response.badMethod()
.setContentTypeText().setEntity("No GET available for endpoint");
// no need to track bytes returned since it's not real payload
response.writeOut(null);
}
public void handleHead(ServletServiceRequest request, ServletServiceResponse response,
OperationDiagnostics stats)
throws IOException { }
public void handlePut(ServletServiceRequest request, ServletServiceResponse response,
OperationDiagnostics stats)
throws IOException { }
public void handlePost(ServletServiceRequest request, ServletServiceResponse response,
OperationDiagnostics stats)
throws IOException { }
public void handleDelete(ServletServiceRequest request, ServletServiceResponse response,
OperationDiagnostics stats)
throws IOException { }
/*
/**********************************************************************
/* Helper methods, overridable
/**********************************************************************
*/
protected ServletServiceRequest constructRequest(HttpServletRequest orig)
{
String path = orig.getRequestURI();
/* First things first: remove servlet path prefix (either override,
* or one used for registration)
*/
if (_basePath == null) { // no base path; use whatever it was registered with
path = _trimPath(path, orig.getServletPath(), true);
} else {
path = _trimPath(path, _basePath, false);
}
// false -> path not yet URL decoded
return new ServletServiceRequest(orig, path, false);
}
/**
* Overridable factory method that is used for creating optional
* {@link OperationDiagnostics} object to pass through, to collect
* statistics.
*/
protected OperationDiagnostics constructMetadata() {
/* 28-Mar-2013, tsaloranta: Let's construct this by default, since
* it will be needed to collect metrics.
*/
return new OperationDiagnostics(_timeMaster.nanosForDiagnostics());
}
protected ServletServiceResponse constructResponse(HttpServletResponse orig) {
return new ServletServiceResponse(orig);
}
/*
/**********************************************************************
/* Helper methods, other
/**********************************************************************
*/
protected String _trimPath(String originalPath, String expectedPrefix,
boolean checkSlash)
{
int prefixLength = expectedPrefix.length();
if (prefixLength == 0) {
return originalPath;
}
if (!originalPath.startsWith(expectedPrefix)) {
LOG.warn("Unexpected Servlet path to trim '{}'; does not start with '{}'; passing as-is",
originalPath, expectedPrefix);
return originalPath;
}
// need to trim one char, slash?
if (checkSlash
&& (originalPath.length() > prefixLength)
&& (expectedPrefix.charAt(prefixLength-1) != '/')
&& (originalPath.charAt(prefixLength) == '/')
) {
++prefixLength;
}
return originalPath.substring(prefixLength);
}
protected ServiceResponse _addStdHeaders(ServiceResponse response)
{
if (_clusterView != null) {
response = _clusterView.addClusterStateInfo(response);
}
return response;
}
}