Java custom tag

1. Compile the **. tld file [html] <? 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"> <! -- Tag library version --> <tlib-version> 1.0 </tlib-version> <! -- Default prefix of the tag library --> <short-name> candy </short-name> <! -- Default URI of the tag library --> <uri>/candy </uri> <! -- Webpage dialog box tag with mask --> <tag> <description> webpage dialog box tag with mask </description> <name> msgdialog </name> <tag-class> candy. tld. msgDialogTag </tag-class> <! -- The TAG body can be a static HTML element, expression language, however, the title text of the <body-content> scriptless </body-content> <attribute> <description> dialog box cannot appear, the default value is "tip" </description> <name> title </name> <required> false </required> <! -- JSP expressions can be used --> <rtexprvalue> true </rtexprvalue> </attribute> <description> specifies the mask height. The screen height is used by default, namely, 100% </description> <name> height </name> <required> false </required> <! -- You can use JSP expressions --> <rtexprvalue> true </rtexprvalue> </attribute> <description> the distance at the top of the dialog box, the default value is 300px </description> <name> top </name> <required> false </required> <! -- You can use a JSP expression --> <rtexprvalue> true </rtexprvalue> </attribute> <description> to specify the width of the dialog box, the default value is 500px </description> <name> boxwidth </name> <required> false </required> <! -- JSP expressions can be used --> <rtexprvalue> true </rtexprvalue> </attribute> <description> basic URL </description> <name> basepath </name> <required> true </required> <! -- JSP expressions can be used --> <rtexprvalue> true </rtexprvalue> </attribute> <description> temporary ID suffix to avoid ID conflict, the default value is the system time in milliseconds. </description> <name> tmpid </name> <required> false </required> <! -- JSP expressions can be used --> <rtexprvalue> true </rtexprvalue> </attribute> </tag> </taglib> 2. compile the tool class [java] package candy. tld; import java. io. *; import javax. servlet. jsp. jspException; import javax. servlet. jsp. tagext. jspFragment; import javax. servlet. jsp. tagext. simpleTagSupport;/** custom tag class in the dialog box with masks */public class MsgDialogTag extends SimpleTagSupport {String title = "tip "; // dialog box title text String height = "100% ";// The height of the mask. The default value is the screen height, that is, the distance from the top of the 100% String top = "300px"; // The default value is 100px String boxwidth = "330px "; // The dialog box width. The default value is 500px String basepath = ""; // basic URL String tmpid = null; // temporary ID suffix to avoid ID conflict, the default value is the system time in milliseconds/** TAG body Processing */public void doTag () throws JspException, IOException {// standard attribute value if (! Height. endsWith ("%") height = height + "px"; if (! Top. endsWith ("px") top = top + "px"; if (! Boxwidth. endsWith ("px") boxwidth = boxwidth + "px"; int titlewidth = Integer. valueOf (boxwidth. replaceAll ("px ","")). intValue ()-22; if (tmpid = null) tmpid = String. valueOf (System. currentTimeMillis (); // temporary ID suffix to avoid ID conflict // get the content of the existing TAG body JspFragment body = this. getJspBody (); StringWriter writer = new StringWriter (); body. invoke (writer); // The StringBuffer sb = new StringBuffer (); sb. append (" <Style> \ n "); sb. append ("# msgbox" + tmpid + "{width:" + boxwidth + "; background: # D6D3CE; border: 1px #848284 solid; padding: 0px; margin: 0 auto;} \ n "); sb. append (". msgicon {float: left; background-image: url ("+ basepath +"/img/msgtitle_icon.jpg); background-repeat: no-repeat; height: 20px; width: 20px ;} \ n "); sb. append (". msgtilte {float: left; text-align: left; background-image: url ("+ basepath +"/img/msgtitle_ B Ack.jpg); background-repeat: repeat-x; line-height: 20px; letter-spacing: 2px; height: 20px; width: "+ titlewidth +" px ;} \ n "); // sb. append (". msgclose {float: left; background-image: url ("// + basepath // +"/img/btn_close.jpg); background-repeat: no-repeat; height: 20px; width: 20px; cursor: pointer;} \ n "); sb. append (". msgmainbox {clear: both; border-top: 1px #848284 solid; text-align: left; padding: 20px; overflow: Uto;} \ n "); sb. append ("</style> \ n"); sb. append ("<div id = 'mask" + tmpid + "'style = 'clear: both; top: 0; left: 0; position: absolute; z-index: 10001; filter: alpha (opacity = 70); background: #000; opacity: 0.7;-moz-opacity: 0.7; height: "+ height +"; width: 100%; '> </div> \ n "); sb. append ("<div id = 'msgprompt" + tmpid + "'style = 'clear: both; top:" + top + "; left: 0; position: absolute; z-index: 10002; width: 100%; text-align: Center '> \ n "); sb. append ("<div id = 'msgbox" + tmpid + "'> \ n"); sb. append ("<div class = 'msgicon '> </div> \ n"); sb. append ("<div class = 'msgtilte '>" + title + "</div> \ n"); // sb. append ("<div class = 'msgclose' onClick = 'closemask" + tmpid // + "() '> </div> \ n"); sb. append ("<div class = 'msgmainbox'> \ n"); // Insert the prompt information sb in the TAG body. append (writer. toString (). trim () + "\ n"); sb. append ("</div> \ n"); sb. append ("</div> \ n"); sb. Append ("</div> \ n"); // sb. append ("<script language = 'javascript '> \ n"); // sb. append ("function closemask" + tmpid + "() {\ n"); // sb. append ("document. getElementById ('mask "+ tmpid // + "'). style. display = 'none'; \ n "); // sb. append ("document. getElementById ('msgprompt "+ tmpid // + "'). style. display = 'none'; \ n "); // sb. append ("} \ n"); // sb. append ("</script> \ n"); sb. append ("</div> \ n"); // output the processing result to getJsp on the page. Context (). getOut (). println (sb);} public String getTitle () {return title;} public void setTitle (String title) {this. title = title;} public String getBasepath () {return basepath;} public void setBasepath (String basepath) {this. basepath = basepath;} public String getHeight () {return height;} public void setHeight (String height) {this. height = height;} public String getTop () {return top;} Public void setTop (String top) {this. top = top;} public String getBoxwidth () {return boxwidth;} public void setBoxwidth (String boxwidth) {this. boxwidth = boxwidth;} public String getTmpid () {return tmpid;} public void setTmpid (String tmpid) {this. tmpid = tmpid;} 3. page import tag [html] <% @ taglib prefix = "candy" uri = "/candy" %> 4. page call Tag [html] <candy: msgdialog basepath = "<% = request. getContextPa Th () %> "> enter the logon password to unlock: <br> <input type = "text" id = "passText"> <input type = "button" onclick = "valSystemLock () "value =" unlock "class =" btn "style =" margin-bottom: 8px; "/> <br> <span id =" valmsg "style =" color: red; "> </span> </candy: msgdialog> in this example, the system is locked as an example to implement and use custom labels.