public class

ServletUtilities

extends Object
java.lang.Object
   ↳ org.jfree.chart.servlet.ServletUtilities

Class Overview

Utility class used for servlet related JFreeChart operations.

Summary

Public Constructors
ServletUtilities()
Public Methods
static String getTempFilePrefix()
Returns the prefix for the temporary file names generated by this class.
static String getTempOneTimeFilePrefix()
Returns the prefix for "one time" temporary file names generated by this class.
static String saveChartAsJPEG(JFreeChart chart, int width, int height, HttpSession session)
Saves the chart as a JPEG format file in the temporary directory.
static String saveChartAsJPEG(JFreeChart chart, int width, int height, ChartRenderingInfo info, HttpSession session)
Saves the chart as a JPEG format file in the temporary directory and populates the ChartRenderingInfo object which can be used to generate an HTML image map.
static String saveChartAsPNG(JFreeChart chart, int width, int height, ChartRenderingInfo info, HttpSession session)
Saves the chart as a PNG format file in the temporary directory and populates the ChartRenderingInfo object which can be used to generate an HTML image map.
static String saveChartAsPNG(JFreeChart chart, int width, int height, HttpSession session)
Saves the chart as a PNG format file in the temporary directory.
static String searchReplace(String inputString, String searchString, String replaceString)
Perform a search/replace operation on a String There are String methods to do this since (JDK 1.4)
static void sendTempFile(String filename, HttpServletResponse response)
Binary streams the specified file in the temporary directory to the HTTP response in 1KB chunks.
static void sendTempFile(File file, HttpServletResponse response, String mimeType)
Binary streams the specified file to the HTTP response in 1KB chunks.
static void sendTempFile(File file, HttpServletResponse response)
Binary streams the specified file to the HTTP response in 1KB chunks.
static void setTempFilePrefix(String prefix)
Sets the prefix for the temporary file names generated by this class.
static void setTempOneTimeFilePrefix(String prefix)
Sets the prefix for the "one time" temporary file names generated by this class.
Protected Methods
static void createTempDir()
Creates the temporary directory if it does not exist.
static void registerChartForDeletion(File tempFile, HttpSession session)
Adds a ChartDeleter object to the session object with the name JFreeChart_Deleter if there is not already one bound to the session and adds the filename to the list of charts to be deleted.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public ServletUtilities ()

Public Methods

public static String getTempFilePrefix ()

Returns the prefix for the temporary file names generated by this class.

Returns
  • The prefix (never null).

public static String getTempOneTimeFilePrefix ()

Returns the prefix for "one time" temporary file names generated by this class.

Returns
  • The prefix.

public static String saveChartAsJPEG (JFreeChart chart, int width, int height, HttpSession session)

Saves the chart as a JPEG format file in the temporary directory.

SPECIAL NOTE: Please avoid using JPEG as an image format for charts, it is a "lossy" format that introduces visible distortions in the resulting image - use PNG instead. In addition, note that JPEG output is supported by JFreeChart only for JRE 1.4.2 or later.

Parameters
chart the JFreeChart to be saved.
width the width of the chart.
height the height of the chart.
session the HttpSession of the client (if null, the temporary file is marked as "one-time" and deleted by the DisplayChart servlet right after it is streamed to the client).
Returns
  • The filename of the chart saved in the temporary directory.
Throws
IOException if there is a problem saving the file.

public static String saveChartAsJPEG (JFreeChart chart, int width, int height, ChartRenderingInfo info, HttpSession session)

Saves the chart as a JPEG format file in the temporary directory and populates the ChartRenderingInfo object which can be used to generate an HTML image map.

SPECIAL NOTE: Please avoid using JPEG as an image format for charts, it is a "lossy" format that introduces visible distortions in the resulting image - use PNG instead. In addition, note that JPEG output is supported by JFreeChart only for JRE 1.4.2 or later.

Parameters
chart the chart to be saved (null not permitted).
width the width of the chart
height the height of the chart
info the ChartRenderingInfo object to be populated
session the HttpSession of the client (if null, the temporary file is marked as "one-time" and deleted by the DisplayChart servlet right after it is streamed to the client).
Returns
  • The filename of the chart saved in the temporary directory
Throws
IOException if there is a problem saving the file.

public static String saveChartAsPNG (JFreeChart chart, int width, int height, ChartRenderingInfo info, HttpSession session)

Saves the chart as a PNG format file in the temporary directory and populates the ChartRenderingInfo object which can be used to generate an HTML image map.

Parameters
chart the chart to be saved (null not permitted).
width the width of the chart.
height the height of the chart.
info the ChartRenderingInfo object to be populated (null permitted).
session the HttpSession of the client (if null, the temporary file is marked as "one-time" and deleted by the DisplayChart servlet right after it is streamed to the client).
Returns
  • The filename of the chart saved in the temporary directory.
Throws
IOException if there is a problem saving the file.

public static String saveChartAsPNG (JFreeChart chart, int width, int height, HttpSession session)

Saves the chart as a PNG format file in the temporary directory.

Parameters
chart the JFreeChart to be saved.
width the width of the chart.
height the height of the chart.
session the HttpSession of the client (if null, the temporary file is marked as "one-time" and deleted by the DisplayChart servlet right after it is streamed to the client).
Returns
  • The filename of the chart saved in the temporary directory.
Throws
IOException if there is a problem saving the file.

public static String searchReplace (String inputString, String searchString, String replaceString)

Perform a search/replace operation on a String There are String methods to do this since (JDK 1.4)

Parameters
inputString the String to have the search/replace operation.
searchString the search String.
replaceString the replace String.
Returns
  • The String with the replacements made.

public static void sendTempFile (String filename, HttpServletResponse response)

Binary streams the specified file in the temporary directory to the HTTP response in 1KB chunks.

Parameters
filename the name of the file in the temporary directory.
response the HTTP response object.
Throws
IOException if there is an I/O problem.

public static void sendTempFile (File file, HttpServletResponse response, String mimeType)

Binary streams the specified file to the HTTP response in 1KB chunks.

Parameters
file the file to be streamed.
response the HTTP response object.
mimeType the mime type of the file, null allowed.
Throws
IOException if there is an I/O problem.

public static void sendTempFile (File file, HttpServletResponse response)

Binary streams the specified file to the HTTP response in 1KB chunks.

Parameters
file the file to be streamed.
response the HTTP response object.
Throws
IOException if there is an I/O problem.

public static void setTempFilePrefix (String prefix)

Sets the prefix for the temporary file names generated by this class.

Parameters
prefix the prefix (null not permitted).

public static void setTempOneTimeFilePrefix (String prefix)

Sets the prefix for the "one time" temporary file names generated by this class.

Parameters
prefix the prefix (null not permitted).

Protected Methods

protected static void createTempDir ()

Creates the temporary directory if it does not exist. Throws a RuntimeException if the temporary directory is null. Uses the system property java.io.tmpdir as the temporary directory. This sounds like a strange thing to do but my temporary directory was not created on my default Tomcat 4.0.3 installation. Could save some questions on the forum if it is created when not present.

protected static void registerChartForDeletion (File tempFile, HttpSession session)

Adds a ChartDeleter object to the session object with the name JFreeChart_Deleter if there is not already one bound to the session and adds the filename to the list of charts to be deleted.

Parameters
tempFile the file to be deleted.
session the HTTP session of the client.