- JAVA General JPEG miniature map of the production and Examples Bean

JAVA General JPEG miniature map of the production and Examples Bean

JAVA General JPEG miniature map of the production and Examples Bean

Description:

Some time ago, a netizen posted online to see a cross-platform Java by the formation Jpeg picture miniature map approach. Recently compiled to form a common category. And the production into a jar packets. To facilitate reuse. And gives examples of the use. (Author: abnerchai; Contact: josserchai@yahoo.com)

First, source code

1, JpegTool.java

/ / JpegTool.java

Package com.abner.jpegtool;

Import javax.imageio.ImageIO;

Import javax.imageio.IIOException;

Import java.awt.image.BufferedImage;

Import java.awt.Image;

Import java.io.File;

Import java.awt.image.AffineTransformOp;

Import java.awt.geom.AffineTransform;

Import com.abner.jpegtool.JpegToolException;

Import java.io. *;

/ **

* This class implements an JPG / JPEG image files microcosm of the method of handling

* That is, to set a JPG file, and can generate a microcosm of the JPG document image files (JPG format)

* Providing a microcosm of images generated three different ways:

* 1, set up miniature paper width, the width of the basis set and the size of the source image file to determine the length of the new miniature paper to generate miniature image

* 2, set the length of microfilm documents, according to the source, and set the length of the size of the image file to determine the width of the new miniature paper to generate miniature image

* 3, set up miniature paper compared to the ratio of the source image file size, according to the size of the source image files and settings to determine the proportion of the size of the new miniature paper to generate miniature image

* The new generation of miniature images than the original image, then that is the source image to enlarge.

* @ Author abnerchai contact: josserchai@yahoo.com

* @ Version 1.0

* @ Exception JpegToolException

* /

(Public class JpegTool

/ / Initialization has been whether

Private boolean isInitFlag = false;

/ / Definition of the source picture with the file name directory path

Private String pic_big_pathfilename = null;

/ / Generate small picture of the store with the file name directory path

Private String pic_small_pathfilename = null;

/ / Definition of generating small picture of a width and height, to one of its on the

Private int smallpicwidth = 0;

Private int smallpicheight = 0;

/ / Definition of the small picture than the proportion of the original picture

Private double picscale = 0;

/ **

* Constructor

* @ Param no parameters

* /

Public JpegTool () (

This.isInitFlag = false;

)

/ **

* Private function, reset all the parameters

* @ Param no parameters

* @ Return did not return parameters

* /

Private void resetJpegToolParams () (

This.picscale = 0;

This.smallpicwidth = 0;

This.smallpicheight = 0;

This.isInitFlag = false;

)

/ **

* @ Param scale settings miniature image of the size of the source image as 0.5 percentage

* @ Throws JpegToolException

* /

Public void SetScale (double scale) throws JpegToolException (

If (scale <= 0) (

Throw new JpegToolException ( "scaling can not be negative and 0!");

)

This.resetJpegToolParams ();

This.picscale = scale;

This.isInitFlag = true;

)

/ **

* @ Param smallpicwidth set the width of miniature images

* @ Throws JpegToolException

* /

Public void SetSmallWidth (int smallpicwidth) throws JpegToolException (

If (smallpicwidth <= 0) (

Throw new JpegToolException (the "epitome of the picture width can not be negative and 0!");

)

This.resetJpegToolParams ();

This.smallpicwidth = smallpicwidth;

This.isInitFlag = true;

)

/ **

* @ Param smallpicheight set a high degree of miniature images

* @ Throws JpegToolException

* /

Public void SetSmallHeight (int smallpicheight) throws JpegToolException (

If (smallpicheight <= 0) (

Throw new JpegToolException (the "epitome of the high degree of picture can not be negative and 0!");

)

This.resetJpegToolParams ();

This.smallpicheight = smallpicheight;

This.isInitFlag = true;

)

/ **

* Generation source image in miniature image

* @ Param pic_big_pathfilename source image file names, URLs (such as windows under C: \ \ pic.jpg; under Linux / home / abner / pic / pic.jpg)

* @ Param pic_small_pathfilename generation of miniature image file names, URLs (such as windows under C: \ \ pic_small.jpg; under Linux / home / abner / pic / pic_small.jpg)

* @ Throws JpegToolException

* /

Public void doFinal (String pic_big_pathfilename, String pic_small_pathfilename) throws JpegToolException (

If (! This.isInitFlag) (

Throw new JpegToolException ( "object initialization parameters did not!");

)

If (pic_big_pathfilename == null | | pic_small_pathfilename == null) (

Throw new JpegToolException ( "file name contains the path is empty!");

)

If ((! Pic_big_pathfilename.toLowerCase (). EndsWith ( "jpg")) & & (! Pic_big_pathfilename.toLowerCase (). EndsWith ( "jpeg "))){

Throw new JpegToolException ( "can only deal with JPG / JPEG files!");

)

If ((! Pic_small_pathfilename.toLowerCase (). EndsWith ( "jpg")) & & (! Pic_small_pathfilename.toLowerCase (). EndsWith ( "jpeg "))){

Throw new JpegToolException ( "can only deal with JPG / JPEG files!");

)

Int smallw = 0;

Int smallh = 0;

/ / Generate new sources picture and the small picture of the document object

File fi = new File (pic_big_pathfilename);

File fo = new File (pic_small_pathfilename);

/ / Object Generation Image Transform

AffineTransform transform = new AffineTransform ();

/ / Read through the source buffer picture file

BufferedImage bsrc = null;

Try (

Bsrc = ImageIO.read (fi);

) Catch (IOException ex) (

Throw new JpegToolException ( "read image files source mistakes!");

)

Int srcw = bsrc.getWidth ();// the length of the original image

Int srch = bsrc.getHeight ();// the width of the original image

Double scale = (double) srcw / srch; / / ratio of the length and width of the image

If (this.smallpicwidth! = 0) (/ / set the width calculated in accordance with the length of

Smallw = this.smallpicwidth; / / The new generation of the length as thumbnails

Smallh = (smallw * srch) / srcw; / / The new generation of the width as thumbnails

) Else if (this.smallpicheight! = 0) (/ / set according to the length of the width obtained

Smallh = this.smallpicheight; / / The new generation of the length as thumbnails

Smallw = (* srcw smallh) / srch; / / The new generation of the width as thumbnails

) Else if (this.picscale! = 0) (/ / set up in accordance with the proportion of narrow set the length and width of image

Smallw = (int) ((float) this.picscale srcw *);

Smallh = (int) ((float) this.picscale srch *);

Else ()

Throw new JpegToolException ( "object initialization parameters incorrect!");

)

System.out.println ( "source file size:" + + srcw "X" + srch);

System.out.println ( "New File Size:" + + smallw "X" + smallh);

Double sx = (double) smallw / srcw; / / small / large proportion of the width of image

Double sy = (double) smallh / srch; / / small / large proportion of the high degree of image

Transform.setToScale (sx and sy); / / image conversion ratio settings

/ / Object generated image conversion

AffineTransformOp ato = new AffineTransformOp (transform, null);

/ / Generate a buffer narrowed Image Object

BufferedImage bsmall = new BufferedImage (smallw, smallh, BufferedImage.TYPE_3BYTE_BGR);

/ / Generate small image

Ato.filter (bsrc, bsmall);

/ / Output small image

Try (

ImageIO.write (bsmall, "jpeg" fo);

) Catch (IOException ex1) (

Throw new JpegToolException ( "into the document as thumbnails wrong!");

)

2, JpegToolException.java

/ / JpegToolException.java

Package com.abner.jpegtool;

/ **

* <p> Description: JpegTool abnormal use of </ p>

* @ Author abnerchai

* @ Version 1.0

* /

Public class JpegToolException extends Exception (

Private String errMsg = "";

Public JpegToolException (String errMsg) (

This.errMsg = errMsg;

)

Public String getMsg () (

Return "JpegToolException:" + this.errMsg;

)

Second, the package produced jar

Compiler above two documents and two class files are stored in the directory: the current directory \ com \ abner \ jpegtool directory. Access to the current directory, the Executive: jar cvf jpegtool.jar com / *; in the current directory will generate a jpegtool.jar document. Published this jar packs, as the future will be able to use other jar, like using the tool kits, Below we give an example.

Third, the use of examples

In order to facilitate, we are in the JSP document examples of the use of the JSP code package, first of all, you set up the class library path, you will jpegtool.jar document Add to the class library path. Then set up your application server class library path, jpegtool.jar Add to your application server class library path. Then test the following JSP code:

<!-Test.jsp ->

<% @ Page contentType = "text / html; charset = GB2312"%>

<% @ Page import = "com.abner.jpegtool.JpegTool"%>

Try (

JpegTool jpegTool = new JpegTool ();

JpegTool.SetSmallWidth (100);

JpegTool.doFinal ( "C: \ \ big.jpeg", "C: \ \ small.jpeg");

) Catch (Exception e) (

E.printStackTrace ();

)

</ Body>

</ Html>