(24) Basic tag of JSP tag (<jsp: Tag name >)

OneCommon Tags1.1 JSP in a total of 8 tags, which are commonly used in 6, this article will introduce the 6 commonly used tags. 1.2 6 kinds of label 1.<jsp:include>

The <jsp:include> tag indicates a file that contains either static or dynamic.

Grammar:
<jsp:include page= "path" flush= "true"/>
Or
<jsp:include page= "path" flush= "true" >
<jsp:param name= "paramname" value= "Paramvalue"/>
</jsp:include>

Note:
1. Page= "path" is a relative path, or an expression that represents a relative path.
2, flush= "true" must use flush to true, and its default value is False.
3, the <jsp:param> clause allows you to pass one or more parameters to the dynamic file, but also in a page
Use multiple <jsp:param> to pass multiple parameters to a dynamic file.

2.<jsp:forward> Tags

• The <jsp:forward> tag indicates the redirection of a static html/jsp file, or a program segment.

Grammar:
<jsp:forward page= "Path"}/>
Or
<jsp:forward page= "path"} >
<jsp:param name= "paramname" value= "Paramvalue"/>
</jsp:forward>

Note:
1, page= "path" is an expression, or a string.
2, <jsp:param> name specifies the parameter name, value specifies the parameter value. Parameters are sent to a dynamic
File, the parameter can be one or more values, and the file must be a dynamic file. To pass multiple parameters
, you can use multiple <jsp:param> in one JSP file to send multiple parameters to a dynamic
File.

3.<jsp:useBean> Tags

The <jsp:useBean> tag is used to create a bean instance in a JSP page and specify its name to
and scope of action.

Grammar:
<jsp:usebean id= "name" scope= "page | Request | Session | Application "TypeSpec/>
There are several possible scenarios in which typespec:
class= "ClassName" | class= "ClassName" type= "TypeName" |
Beanname= "Beanname" type= "TypeName" | Type= "TypeName" |

Note:
You must use class or type, and you cannot use both class and beanname. Beanname says
The name of the bean, in the form of "A.B.C".

4.<jsp:getProperty> Tags

The <jsp:getProperty> tag represents the value of the property that gets the bean and converts it to a string, which
After inserting it into the output page.

Grammar:
<jsp:getproperty name= "name" property= "PropertyName"/>

Note:
1. Before using <jsp:getProperty>, you must use <jsp:useBean> to create it.
2. You cannot use <jsp:getProperty> to retrieve an attribute that has already been indexed.
3, can be used together with the JavaBeans components <jsp:getproperty>, but not with enterprise
With Java beans.

5.<jsp:setProperty> Tags

• The <jsp:setProperty> tag indicates the value of the attribute used to set the bean.

Grammar:
<jsp:setproperty name= "Beanname" prop_expr/>
There are several possible scenarios in which prop_expr:
property= "*" | Property= "PropertyName" | Property= "PropertyName"
param= "ParameterName" | Property= "PropertyName" value= "PropertyValue"

Note:
Use Jsp:setproperty to assign a value to a bean's properties, which can be implemented in two ways.
1. Use Jsp:setproperty after Jsp:usebean:
<jsp:usebean id= "MyUser" .../>
...
<jsp:setproperty name= "user" property= "user" .../>
In this way, the Jsp:setproperty will be executed.
2, Jsp:setproperty appears in the Jsp:usebean tag:
<jsp:usebean id= "MyUser" ... > ...
<jsp:setproperty name= "user" property= "user" .../>
</jsp:useBean>
In this way, Jsp:setproperty will only be executed when the new object is instantiated.

* The name value in <jsp:setProperty> should be the same as the ID value in <jsp:useBean>.

6.<jsp:plugin> Tags

• The <jsp:plugin> tag means executing an applet or bean, and, if possible, downloading a Java

The plugin is used to execute it.

Grammar:
<jsp:plugin
Type= "Bean | Applet
Code= "Classfilename"
Codebase= "Classfiledirectoryname"
[Name= "InstanceName"]
[archive= "uritoarchive, ..."]
[align= "bottom | top | middle | left | right"]
[height= "Displaypixels"]
[width= "Displaypixels"]
[hspace= "Leftrightpixels"]
[vspace= "Topbottompixels"]
[jreversion= "Jreversionnumber | 1.1"]
[nspluginurl= "Urltoplugin"]
[iepluginurl= "Urltoplugin"] >
[<jsp:params>
[<jsp:param name= "parametername" value= "{parametervalue | <%=
Expression%>} "/>]+
</jsp:params>]
[<jsp:fallback> text message for user </jsp:fallback>]
</jsp:plugin>

Note:
The <jsp:plugin> element is used to play or display an object in the browser (typically applets and
Bean), and this display requires a Java plugin in the browser.
When the JSP file is compiled and sent to the browser, the,<jsp:plugin> element will be replaced by the browser version.
Change to <object> or <embed> element. Note,<object> is used for HTML 4.0,<embed>
In HTML 3.2.
In general, the,<jsp:plugin> element specifies whether the object is an applet or a bean, and also specifies
The name of the class, and the location, also specifies where the Java plugin will be downloaded from.

(24) Basic tag of JSP tag (<jsp: Tag name >)