JSP uses tags to control content display

JSP uses the <C: Choose> label to control content display

 
<C: Choose> <C: When test = "$ {task. status EQ 1} "> not started </C: When> <C: When test =" $ {task. status EQ 2} "> in progress </C: When> <C: When test =" $ {task. status EQ 3} "> terminated </C: When> <C: When test =" $ {task. status EQ 4} "> completed </C: When> </C: Choose>
 

<C: Choose> <C: When test = "$ {typename. name = NULL} ">  
 
 

<C: Choose> is used only as the parent label of <C: When> and <C: otherwise>. Syntax <C: Choose> body content (<when> and <otherwise>) </C: Choose> attributes are unrestricted. <C: Choose> the body content can only be: · blank spaces · 1 or more <C: When> · 0 or more <C: otherwise> indicate that <C: When> and <C: when using otherwise> for process control, both of them must be sub-labels of <C: Choose>: <C: Choose >:< C: When> </C: When>: <C: otherwise> </C: otherwise >:</C: Choose> ● <C: When>ProgramThe same as the when. Syntax <C: When test = "testcondition"> body content </C: When> attribute name description El type must be set to test by default. If the expression returns true, the body content is executed. If the value is false, y Boolean is unlimited? <C: When> must be the same between <C: Choose> and </C: Choose>? In <C: Choose>, <C: When> must be specified before <C: otherwise>. <C: When> must have the test attribute. When the expression result in test is true, the body content is executed. If the value is false, the body content is not executed.