问题
I am trying to load image from PostgreSQL database into jaspersoft ireports(4.0) but I am receiving an error.
In PostgreSQL image is stored as bytea object. In ireports I have changed the property of image field to java.io.InputStream.
After placing the image in report following properties were set:
Expression class: java.io.InputStream
Image expression: image field
I also tried this tutorial to show blob images in ireport.
Following error is displayed:
Error filling print... Image read failed.
Setting up the file resolver...
net.sf.jasperreports.engine.JRException: Image read failed.
at net.sf.jasperreports.engine.util.JRJdk14ImageReader.readImage(JRJdk14ImageReader.java:73)
at net.sf.jasperreports.engine.util.JRImageLoader.loadImage(JRImageLoader.java:245)
at net.sf.jasperreports.engine.JRImageRenderer.getImage(JRImageRenderer.java:476)
at net.sf.jasperreports.engine.JRImageRenderer.getDimension(JRImageRenderer.java:512)
at net.sf.jasperreports.engine.fill.JRFillImage.fitImage(JRFillImage.java:1251)
at net.sf.jasperreports.engine.fill.JRFillImage.prepare(JRFillImage.java:1173)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.prepareElements(JRFillElementContainer.java:329)
at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:419)
at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:378)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2038)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:760)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:270)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:946)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:845)
at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:58)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:417)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:247)
at com.jaspersoft.ireport.designer.compiler.IReportCompiler.run(IReportCompiler.java:877)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)
Print not filled. Try to use an EmptyDataSource...
回答1:
In PostgreSQL the bytea type is not a BLOB, and you can't use a stream. In SQL standard terms it is a byte string. It should be loaded to a byte array in Java.
If you want to use BLOB techniques in PostgreSQL you must use the large objects feature.
http://www.postgresql.org/docs/current/interactive/largeobjects.html
回答2:
spending nearly one day, finally found the solution;
- in sql query
select convert(your_image,'base64') as img from yourtable - set image expression class to
java.io.InputStream - in image expression
net.sf.jasperreports.engine.util.JRImageLoader.getInstance(new SimpleJasperReportsContext()).loadAwtImageFromBytes(javax.xml.bind.DatatypeConverter.parseBase64Binary($F{img}))
EDIT:
My Postgresql version is : 9.4,
Thanks to FiruzzZ he stated that in postgresql 9.1 instead of convert function, encode(bytea,'base64') is available.
回答3:
Displaying Image from blob (postgresql) to Image in iReport
In Postgresql image is stored as blob-oid
Code inside ReportController
- fetch that oid string from database convert it into byte
- convert byte array value in InputStream value
- map it to the parameter that will be used inside iReport
- take one Image element change its type to java.io.InputStream
- Create one parameter of type java.io.InputStream (use the same name as mapped inside ReportController)
- Now Build project and Run
来源：https://stackoverflow.com/questions/8430313/displaying-image-in-ireports-using-postgresql