org.sandev.tools.HTTP
Class ServletInput

java.lang.Object
  org.sandev.tools.HTTP.ServletInput

All Implemented Interfaces:

org.sandev.basics.util.UIRenderInput, org.sandev.basics.util.UIRenderOperand

public class ServletInput
extends java.lang.Object
implements org.sandev.basics.util.UIRenderInput

Provides access to the HttpServletRequest parameter map.

Under standard form submission, the content type of the request is

application/x-www-form-urlencoded

and HttpServletRequest.getParameterMap works just fine. However in the case where file upload is desired, the standard form encoding is overridden (by including enctype="multipart/form-data" in the form declaration) which changes the content type to

multipart/form-data; boundary=---------------------------7d426931f0198

and HttpServletRequest.getParameterMap provides nothing. What we want is for:

• The file to be uploaded, with no existing file collisions, to a known location where it can be referenced by the browser
• The "filename" parameter to be set to the new uploaded file name
• An extra "SAND_UploadedFileSource" parameter to hold the original file name
• Access to all the parameters as normally occurs.

Here's how this works:

1. The user is editing a form generated from a struct with a field called "filename". This becomes a filename prompt because the field is metatype uploadedimage, or because the form definition was manually transformed to type="file". The user selects a file to upload, and the contents are submitted back triggered by the enctype="multipart/form-data". The default rendering sets the encoding type if it finds a containing span of type uploadedimage/file.
2. XHTMLSandUIServlet sets the SANDUploadDirectory request attribute to the value of UIFormAdaptorCallback.getInboundFilesDir(). In a typical approach, this is set to a relative path off the default runtime directory. In a production environment, this directory would be symlinked to a networked area with backup.
3. XHTMLSandUIServlet also calls UIFormAdaptorCallback.setInboundFilesDir() so that uploaded filenames can be trapped and converted into their corresponding href in UIFormAdaptorCallback.filterDisplayText.

Files are uploaded without any type or size checking. Since this is for authorized users only, it didn't seem worth the extra work necessary on this pass. The next step would be to provide a setFileTypes(String[]) method to set the allowed MIME file types. That means extending the UIRenderInput interface with this declaration, and sourcing the values from the SandUI definition at runtime.

Field Summary

protected java.util.Map

paramMap Our map of the form parameters.

Constructor Summary

ServletInput()

Method Summary

protected void	addExistingParamsToMap(javax.servlet.http.HttpServletRequest req) The standard HttpServletRequest map is immutable, so we typically make a copy to pass additional useful information.
protected void	echoRequest(javax.servlet.http.HttpServletRequest req) Dump a copy of the incoming request.
protected java.lang.String	getAttributeValue(java.lang.String attrName, java.lang.String text) Given a string with an html attribute value in it, and the attribute name, return the value or null if not found.
protected java.lang.String	getBoundary(java.lang.String line) Given a content text type specification, return the boundary text.
java.util.Map	getInputParameters()
void	init(java.lang.Object req) The initialization object in this case is an HttpServletRequest
protected java.lang.String	readFileContents(javax.servlet.ServletInputStream in, java.lang.String boundary, java.lang.String filename, java.lang.String path) Read the contents into a new file, returning the new file name.
protected java.lang.String	readLine(javax.servlet.ServletInputStream in) Read a line of input from the input stream and return it minus the terminating CRLF.
protected java.lang.String	readParameterValue(javax.servlet.ServletInputStream in, java.lang.String boundary) Read a parameter value from the input stream.
protected void	readToContents(javax.servlet.ServletInputStream in) Read lines until we hit an empty line.
protected java.lang.String	readToLine(javax.servlet.ServletInputStream in, java.lang.String linePrefix) Read lines until reading one starting with the specified prefix.
protected void	uploadAndBuildMap(java.lang.String boundary, javax.servlet.http.HttpServletRequest req) Given a multipart form request, upload the file and reconstruct the parameter map.

Methods inherited from class java.lang.Object

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

Field Detail

paramMap

protected java.util.Map paramMap

Our map of the form parameters.

Constructor Detail

ServletInput

public ServletInput()

Method Detail

init

public void init(java.lang.Object req)

The initialization object in this case is an HttpServletRequest

Specified by:

init in interface org.sandev.basics.util.UIRenderOperand

getInputParameters

public java.util.Map getInputParameters()

Specified by:

getInputParameters in interface org.sandev.basics.util.UIRenderInput

addExistingParamsToMap

protected void addExistingParamsToMap(javax.servlet.http.HttpServletRequest req)

The standard HttpServletRequest map is immutable, so we typically make a copy to pass additional useful information. This method adds the additional fields, and all of the fields originally in the request. Assumes paramMap is initialized.

echoRequest

protected void echoRequest(javax.servlet.http.HttpServletRequest req)

Dump a copy of the incoming request. The input gets copied on a byte-by-byte basis to ServletInputTest.out for use in debugging or other analysis.

getBoundary

protected java.lang.String getBoundary(java.lang.String line)

Given a content text type specification, return the boundary text. The given text looks something like:

multipart/form-data; boundary=---------------------------7d426931f0198

readLine

protected java.lang.String readLine(javax.servlet.ServletInputStream in)
                             throws java.io.IOException

Read a line of input from the input stream and return it minus the terminating CRLF. Return null if nothing was read.

Throws:

java.io.IOException

readToLine

protected java.lang.String readToLine(javax.servlet.ServletInputStream in,
                                      java.lang.String linePrefix)
                               throws java.io.IOException

Read lines until reading one starting with the specified prefix. Return the prefixed line or null if end of stream.

Throws:

java.io.IOException

getAttributeValue

protected java.lang.String getAttributeValue(java.lang.String attrName,
                                             java.lang.String text)

Given a string with an html attribute value in it, and the attribute name, return the value or null if not found. So if asked for "name" from the text

Content-Disposition: form-data; name="MyForm.form_action"

this method returns MyForm.form_action. If asked for "foo" from the same text, then this method returns null.

If the attribute is found, this method returns the interned string value, so the result can be safely used as a hash key.

readToContents

protected void readToContents(javax.servlet.ServletInputStream in)
                       throws java.io.IOException

Read lines until we hit an empty line. That empty line signals the start of contents.

Throws:

java.io.IOException

uploadAndBuildMap

protected void uploadAndBuildMap(java.lang.String boundary,
                                 javax.servlet.http.HttpServletRequest req)

Given a multipart form request, upload the file and reconstruct the parameter map.

readFileContents

protected java.lang.String readFileContents(javax.servlet.ServletInputStream in,
                                            java.lang.String boundary,
                                            java.lang.String filename,
                                            java.lang.String path)
                                     throws java.io.IOException

Read the contents into a new file, returning the new file name.

Throws:

java.io.IOException

readParameterValue

protected java.lang.String readParameterValue(javax.servlet.ServletInputStream in,
                                              java.lang.String boundary)
                                       throws java.io.IOException

Read a parameter value from the input stream. Leave the stream after reading the closing boundary.

Throws:

java.io.IOException