自定义一个简单的标记开发。需要一个标记处理器，一个tld文件，一个jsp文件。
simpletag.jsp
<%@ taglib prefix="my" uri="simple" %> <html> <body> <em><p>Movie List</p></em><br> <my:do> Name:${movie} author:${author}<br> </my:do> </body> </html>
simpleTag.tld
<?xml version="1.0" encoding="UTF-8" ?> <taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <tlib-version>1.2</tlib-version> <uri>simple</uri> <tag> <description>Simple Tag</description> <name>do</name> <tag-class>foo.SimpleTagTest</tag-class> <body-content>scriptless</body-content> </tag> </taglib>
SimpleTagTest.java
package foo; import javax.servlet.jsp.JspException; import javax.servlet.jsp.tagext.SimpleTagSupport; import java.io.IOException; import java.util.Map; import java.util.HashMap; import java.util.Map.Entry; public class SimpleTagTest extends SimpleTagSupport { //String[] movie = {"Big War","Love","A Happy Day"}; Map<String,String> movieList = new HashMap<String,String>(); public void doTag() throws JspException,IOException { movieList.put("Big War","jack"); movieList.put("Love","jenny"); movieList.put("A Happy Day","hany"); for(Map.Entry movie : movieList.entrySet()){ getJspContext().setAttribute("movie",movie.getKey()); getJspContext().setAttribute("author",movie.getValue()); getJspBody().invoke(null); } } }
标记处理器是个java代码文件，继承SimpleTagSuport类，并重写doTag方法。invoke方法的参数null的意思是指输出到响应。
上面的标记体并没有标记体属性，下面的例子展示具有属性的简单标记。
simpletag2.jsp
<%@ taglib prefix="mytag2" uri="simple2" %> <html> <body> <% pageContext.setAttribute("MOVIE","Happy Day"); %> <mytag2:do movieName="${MOVIE}" > name:${MovieName} </mytag2:do> </body> </html>
SimpleTagTest2.tld
<?xml version="1.0" encoding="UTF-8" ?> <taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <tlib-version>1.2</tlib-version> <uri>simple2</uri> <tag> <description>Simple2 Tag</description> <name>do</name> <tag-class>foo.SimpleTagTest2</tag-class> <body-content>scriptless</body-content> <attribute> <name>movieName</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib>
SimpleTagTest2.java
package foo; import javax.servlet.jsp.JspException; import javax.servlet.jsp.tagext.SimpleTagSupport; import java.io.IOException; import java.util.Map; import java.util.HashMap; import java.util.Map.Entry; public class SimpleTagTest2 extends SimpleTagSupport { private String movieName; public void setMovieName(String movieName) { this.movieName = movieName; } public void doTag() throws JspException,IOException { getJspContext().setAttribute("MovieName",movieName); getJspBody().invoke(null); } }
以上代码很简单就不在赘言了。