thredds.server.reify

Class ReifyController

java.lang.Object

thredds.server.reify.ReifyController

@Controller
 @RequestMapping(value="/download")
public class ReifyController
extends java.lang.Object

Local File Materialization (aka reification) for server-side computing. The tag for this controller is .../download/*

The goal for this controller is to allow external code to have the thredds server materialize a dataset into the file system.

Note that this functionality is not strictly necessary since it could all be done on the client side. Since the server is doing all of the work of converting a dataset to a file, the client does not need to have its own code for this. This means: 1. It is lightweight WRT the client 2. It is language independent

Assumptions: 1. The external code has authenticated to the thredds server using some authentication mechanism such as client-side certificates or tomcat roles.

2. The external code is running on the same machine as the thredds server, or at least has a common file system so that file system writes by thredds are visible to the external code.

Note that in order to support downloading of non-file datasets (e.g. via DAP2 or DAP4) this controller will re-call the server to obtain the output of the request. Experimentation shows this is not a problem. Circularity is tested to ensure the no download loop occurs.

Issues: 1. What file formats are allowed for materialized datasets? - Currently only netcdf-3 (classic) and netcdf-4 (enhanced).

A set of query parameters control the operation of this servlet. Note that all of the query parameter values (but not keys) are assumed to be url-encoded (%xx), so beware. Also, all return values are url-encoded.

Download Request ---------------- Download parameters: - request=download -- specify the action - format=netcdf3|netcdfd4 -- specify the download format - url={a thredds server dataset access url} -- specify the actual dataset. - target={path of the downloaded file} -- if it already exists, then it will be overwritten. Notes: 1. the host, port and servlet prefix of the url will be ignored and replaced with the "+/thredds" of the thredds server. This is to prevent attempts to use the thredds server to access external data sources, which would otherwise provide a security leak. 2. The target path must be a relative path. It is interpreted as relative to the value of a -Dtds.download.dir java flag, which must specify an absolute path to a directory into which the downloads are stored. Assuming the Tomcat server is being used, then the path must be writeable by user tomcat, which means that its owner will end up being user tomcat or at least tomcat must be in the group assigned to this directory.

Return value: download=

Misc Parameters: - testinfo={testing info} -- for testing purposes

Inquire Request ---------------- Download parameters: - request=inquire -- Inquire about various parameters - inquire={semicolon separated arguments} -- Inquire about the default download dir

Return value: ={value of the requested key}

Field Summary

Fields

Modifier and Type	Field and Description
protected ucar.nc2.write.Nc4Chunking	chunking
protected static boolean	DEBUG
protected static java.lang.String	DEFAULTDOWNLOADDIR
protected static java.lang.String	DEFAULTREQUESTNAME
protected static java.lang.String	DEFAULTSERVLETNAME
protected java.lang.String	downloaddir
protected static java.lang.String	FILESERVERSERVLET
protected boolean	getInitialized
protected boolean	initialized
protected thredds.server.reify.Parameters	params
protected javax.servlet.http.HttpServletRequest	req
protected java.lang.String	requestname
protected javax.servlet.http.HttpServletResponse	res
protected java.lang.String	server
protected static java.lang.String	STATUSCODEHEADER
protected ucar.nc2.write.Nc4Chunking.Strategy	strategy
protected TdsContext	tdsContext
static TdsContext	testTdsContext
protected java.lang.String	threddsname

Constructor Summary

Constructors

Constructor and Description
ReifyController()

Method Summary

Modifier and Type	Method and Description
protected boolean	canCopy(java.lang.String truepath, thredds.server.reify.ReifyUtils.FileFormat targetformat)
protected java.lang.String	directAccess(java.lang.String relpath, javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)
void	doGet(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)
protected void	download(java.util.Map<java.lang.String,java.lang.String> result)
protected static java.lang.String	escapeString(java.lang.String s) Given a typical string, insert backslashes before '"' and '\\' characters and control characters.
void	init()
void	initGet(javax.servlet.http.HttpServletRequest req) Invoked on first get so that everything is available, especially Spring stuff.
protected void	inquire(java.util.Map<java.lang.String,java.lang.String> result)
protected void	makeNetcdf3(ucar.nc2.NetcdfFile ncfile, java.lang.String target)
protected void	makeNetcdf4(ucar.nc2.NetcdfFile ncfile, java.lang.String target)
protected void	reply(java.util.Map<java.lang.String,java.lang.String> result)
protected void	reply(java.lang.String sresult)
protected void	sendError(int code, java.lang.String msg)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEBUG

protected static final boolean DEBUG

See Also:

Constant Field Values

DEFAULTSERVLETNAME

protected static final java.lang.String DEFAULTSERVLETNAME

See Also:

Constant Field Values

DEFAULTREQUESTNAME

protected static final java.lang.String DEFAULTREQUESTNAME

See Also:

Constant Field Values

DEFAULTDOWNLOADDIR

protected static final java.lang.String DEFAULTDOWNLOADDIR

See Also:

Constant Field Values

STATUSCODEHEADER

protected static final java.lang.String STATUSCODEHEADER

See Also:

Constant Field Values

FILESERVERSERVLET

protected static final java.lang.String FILESERVERSERVLET

See Also:

Constant Field Values

testTdsContext

public static TdsContext testTdsContext

tdsContext

@Autowired
protected TdsContext tdsContext

req

protected javax.servlet.http.HttpServletRequest req

res

protected javax.servlet.http.HttpServletResponse res

params

protected thredds.server.reify.Parameters params

downloaddir

protected java.lang.String downloaddir

initialized

protected boolean initialized

getInitialized

protected boolean getInitialized

server

protected java.lang.String server

requestname

protected java.lang.String requestname

threddsname

protected java.lang.String threddsname

strategy

protected ucar.nc2.write.Nc4Chunking.Strategy strategy

chunking

protected ucar.nc2.write.Nc4Chunking chunking

Constructor Detail

ReifyController

public ReifyController()
                throws javax.servlet.ServletException

Throws:

javax.servlet.ServletException

Method Detail

init

public void init()
          throws javax.servlet.ServletException

Throws:

javax.servlet.ServletException

initGet

public void initGet(javax.servlet.http.HttpServletRequest req)
             throws thredds.server.reify.ReifyUtils.SendError

Invoked on first get so that everything is available, especially Spring stuff.

Throws:

thredds.server.reify.ReifyUtils.SendError

doGet

@RequestMapping(value="**")
public void doGet(javax.servlet.http.HttpServletRequest req,
                                              javax.servlet.http.HttpServletResponse res)
                                       throws javax.servlet.ServletException

Throws:

javax.servlet.ServletException

sendError

protected void sendError(int code,
                         java.lang.String msg)

reply

protected void reply(java.util.Map<java.lang.String,java.lang.String> result)

reply

protected void reply(java.lang.String sresult)

download

protected void download(java.util.Map<java.lang.String,java.lang.String> result)

inquire

protected void inquire(java.util.Map<java.lang.String,java.lang.String> result)

makeNetcdf4

protected void makeNetcdf4(ucar.nc2.NetcdfFile ncfile,
                           java.lang.String target)
                    throws java.io.IOException

Throws:

java.io.IOException

makeNetcdf3

protected void makeNetcdf3(ucar.nc2.NetcdfFile ncfile,
                           java.lang.String target)
                    throws java.io.IOException

Throws:

java.io.IOException

escapeString

protected static java.lang.String escapeString(java.lang.String s)

Given a typical string, insert backslashes before '"' and '\\' characters and control characters.

directAccess

protected java.lang.String directAccess(java.lang.String relpath,
                                        javax.servlet.http.HttpServletRequest req,
                                        javax.servlet.http.HttpServletResponse res)

canCopy

protected boolean canCopy(java.lang.String truepath,
                          thredds.server.reify.ReifyUtils.FileFormat targetformat)