我试图添加一个图像到我的jasperReport，但它不工作，它停止时调用：

JasperRunManager.runReportToPdf ....

我在数据库中将图像类型设置为BLOB，并在“file.jrxml”中将其设置为
字段--〉图像文件
字段类--〉Oracle数据库.
和图像属性：
图像表达式-〉$F{图像文件}.getBinaryStream（）
表达式类-〉java.lang.String
消息错误：

12:22:24,863 INFO  [STDOUT] 12:22:24,862 ERROR [JRFillSubreport] Fill 1: exception
net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression : 
Source text : $F{IMAGE_FILE}.getBinaryStream()
...
...
Caused by: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'oracle.sql.BLOB@5d17f1ea' with class 'oracle.sql.BLOB' to class 'oracle.sql.BLOB'
at     org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:360)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.castToType(ScriptBytecodeAdapter.java:599)
...
...
12:22:24,863 ERROR [STDERR] net.sf.jasperreports.engine.JRRuntimeException: net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression : 
Source text : $F{IMAGE_FILE}.getBinaryStream()

所以主要错误无法解决，也找不到原因：

12:22:24,868 ERROR [STDERR] Caused by: net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression : 
Source text : $F{IMAGE_FILE}.getBinaryStream()
12:22:24,869 ERROR [STDERR] Caused by: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'oracle.sql.BLOB@5d17f1ea' with class 'oracle.sql.BLOB' to class 'oracle.sql.BLOB'