如何在Jasper中使用路径之前检查文件是否存在

Question

I have a jrxml which has a node as follows,

<image>
  <reportElement x="181" y="0" width="209" height="74"/>
  <imageExpression class="java.lang.String"><![CDATA["logo.jpg"]]></imageExpression>
</image>

How can I check whether physical file logo.jpg exists or not? If doesn't exists, how to fall back to a default image "default.jpg"?

Answer 1

<variable name="LOGO" class="java.lang.String">
    <variableExpression>
        <![CDATA[(new File("logo.jpg").isFile())? "logo.jpg":"default.jpg"]]>
    </variableExpression>
    <initialValueExpression>
        <![CDATA[(new File("logo.jpg").isFile())? "logo.jpg":"default.jpg"]]>
    </initialValueExpression>
</variable>

<image>
  <reportElement x="181" y="0" width="209" height="74"/>
  <imageExpression class="java.lang.String"><![CDATA[$V{LOGO}]]></imageExpression>
</image>

Got clue from this site

Answer 2

You can use exists in the Java code, if that's what you're using to check with. Not quite sure if you're asking for another approach that involves the XML itself.

If file doesn't exist, then you would just map the default image.

Answer 3

Send your image path using parameter or field in jasper report. for example I am sending image path using field.Name of field is image imagePath . If you have a image named logo.png , path of image as string other wise set path of default image. and write this syntax with image.

<image>
    <reportElement uuid="0db5b93f-46e4-4aaa-aac9-5a6d090d7eb6" x="127" y="23" width="206" height="78"/>
    <imageExpression><![CDATA[$F{imagePath}]]></imageExpression>
</image>

Enjoy...