1 package com.dev.sen; 2  3 import java.io.IOException; 4  5 import javax.servlet.jsp.JspException; 6 import javax.servlet.jsp.tagext.SimpleTagSupport; 7 /** 8  * 自定义标签在页面上输出hello World 9  * @author WangSen10  * @date 2014-6-2811  * @time 下午7:22:3612  */13 public class HelloWorldTag extends SimpleTagSupport {14     /**15      * 重写doTag方法，该方法在标签结束生成页面内容16      */17     @Override18     public void doTag() throws JspException, IOException {19         getJspContext().getOut().write("Hello World !");20     }21 22 }

 1 <?xml version="1.0" encoding="UTF-8" ?> 2 <taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3     xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" 4     version="2.0"> 5     <description>my customTag</description> 6     <tlib-version>1.0</tlib-version> 7     <short-name>mytag</short-name> 8     <!-- 标签库的URL --> 9     <uri>http://www.dev.com/taglib</uri>10     <tag>11         <description>Outputs Hello, World</description>12         <!-- 标签名 -->13         <name>helloWorld</name>14         <!-- 标签处理类 -->15         <tag-class>com.dev.sen.HelloWorldTag</tag-class>16         <!-- 定义标签体为空 -->17         <body-content>empty</body-content>18     </tag>19 </taglib>

  1 package com.dev.sen;  2   3 import java.io.IOException;  4 import java.sql.Connection;  5 import java.sql.DriverManager;  6 import java.sql.ResultSet;  7 import java.sql.ResultSetMetaData;  8 import java.sql.SQLException;  9 import java.sql.Statement; 10  11 import javax.servlet.jsp.JspException; 12 import javax.servlet.jsp.JspWriter; 13 import javax.servlet.jsp.tagext.SimpleTagSupport; 14  15 /** 16  * 根据sql语句查询数据库 17  *  18  * @author WangSen 19  * @date 2014-6-28 20  * @time 下午8:50:19 21  */ 22 public class QueryTag extends SimpleTagSupport { 23     private String driver; 24     private String url; 25     private String user; 26     private String password; 27     private String sql; 28  29     public String getDriver() { 30         return driver; 31     } 32  33     public void setDriver(String driver) { 34         this.driver = driver; 35     } 36  37     public String getUrl() { 38         return url; 39     } 40  41     public void setUrl(String url) { 42         this.url = url; 43     } 44  45     public String getUser() { 46         return user; 47     } 48  49     public void setUser(String user) { 50         this.user = user; 51     } 52  53     public String getPassword() { 54         return password; 55     } 56  57     public void setPassword(String password) { 58         this.password = password; 59     } 60  61     public String getSql() { 62         return sql; 63     } 64  65     public void setSql(String sql) { 66         this.sql = sql; 67     } 68     /** 69      * 执行sql查询并输出结果 70      */ 71     @Override 72     public void doTag() throws JspException, IOException { 73         Connection conn = null; 74         Statement st = null; 75         ResultSet rs = null; 76         ResultSetMetaData rsmd = null; 77         try { 78             Class.forName(driver);//注册驱动 79             conn = DriverManager.getConnection(url,user,password);//获取连接 80             st = conn.createStatement();//创建Statement 81             rs =  st.executeQuery(sql); //执行查询 82             rsmd =  rs.getMetaData(); 83             //获取列数目 84             int columnConout  = rsmd.getColumnCount(); 85             //获取页面输出流 86             JspWriter out = getJspContext().getOut(); 87             //在页面输出表格 88             out.write("<table border=‘1‘ bgcolor=‘#9999cc‘  width=‘400‘>"); 89             while (rs.next()) { 90                 out.write("<tr>"); 91                 //逐列遍历查询到的数据 92                 for (int i = 0; i < columnConout; i++) { 93                     out.write("<td>"); 94                     out.write(rs.getString(i+1)); 95                     out.write("</td>"); 96                 } 97                 out.write("</tr>"); 98             } 99             out.write("</table>");100         } catch (ClassNotFoundException e) {101             e.printStackTrace();102             throw new JspException("自定义标签错误", e);103         } catch (SQLException e) {104             e.printStackTrace();105             throw new JspException("自定义标签错误", e);106         }finally{107             try {108                 //关闭结果集109                 if(rs!=null&&!rs.isClosed()){110                     rs.close();111                 }112                 if(st!=null&&!st.isClosed()){113                     st.close();114                 }115                 if(conn!=null&&!conn.isClosed()){116                     conn.close();117                 }118             } catch (SQLException e) {119                 e.printStackTrace();120             }121         }122         123     }124 }

 1     <!-- 定义带属性的标签 --> 2     <tag> 3         <description>根据sql语句查询数据库</description> 4         <name>query</name> 5         <tag-class>com.dev.sen.QueryTag</tag-class> 6         <body-content>empty</body-content> 7         <!-- 配置标签属性 --> 8         <attribute> 9             <description>driverName</description>10             <name>driver</name>11             <required>true</required>12             <fragment>true</fragment>13         </attribute>14         <attribute>15             <description>url</description>16             <name>url</name>17             <required>true</required>18             <fragment>true</fragment>19         </attribute>20         <attribute>21             <description>user</description>22             <name>user</name>23             <required>true</required>24             <fragment>true</fragment>25         </attribute>26         <attribute>27             <description>password</description>28             <name>password</name>29             <required>true</required>30             <fragment>true</fragment>31         </attribute>32         <attribute>33             <description>querysql</description>34             <name>sql</name>35             <required>true</required>36             <fragment>true</fragment>37         </attribute>38     </tag>

 1 package com.dev.sen; 2  3 import java.io.IOException; 4 import java.util.Collection; 5  6 import javax.servlet.jsp.JspException; 7 import javax.servlet.jsp.tagext.SimpleTagSupport; 8  9 /**10  * 迭代输出集合元素11  * 12  * @author WangSen13  * @date 2014-6-2814  * @time 下午9:28:5115  */16 public class IteratorTag extends SimpleTagSupport {17     private String collection;18     private String item;19 20     public String getCollection() {21         return collection;22     }23 24     public void setCollection(String collection) {25         this.collection = collection;26     }27 28     public String getItem() {29         return item;30     }31 32     public void setItem(String item) {33         this.item = item;34     }35 36     @SuppressWarnings("rawtypes")37     @Override38     public void doTag() throws JspException, IOException {39         // 从page scope 中获取属性名为collection的集合40         Collection itemList = (Collection) getJspContext().getAttribute(41                 collection);42         // 遍历集合43         for (Object s : itemList) {44             //将集合元素设置到page scope中45             getJspContext().setAttribute(item, s);46             /* 输出标签体 47              *getJspBody()方法返回标签所包含的标签体：JspFragment对象48              *执行该对象的invoke()方法，即可输出标签体的内容49              */50             getJspBody().invoke(null);51         }52     }53 54 }

 1     <tag> 2         <description>Iterator Tag</description> 3         <name>iterator</name> 4         <tag-class>com.dev.sen.IteratorTag</tag-class> 5         <body-content>scriptless</body-content> 6         <attribute> 7             <description>collection name </description> 8             <name>collection</name> 9             <required>true</required>10             <fragment>true</fragment>11         </attribute>12         <attribute>13             <description>item</description>14             <name>item</name>15             <required>true</required>16             <fragment>true</fragment>17         </attribute>18     </tag>

 1 package com.dev.sen; 2  3 import java.io.IOException; 4  5 import javax.servlet.jsp.JspException; 6 import javax.servlet.jsp.JspWriter; 7 import javax.servlet.jsp.tagext.JspFragment; 8 import javax.servlet.jsp.tagext.SimpleTagSupport; 9 10 /**11  * 以页面片段做为属性的标签12  * 13  * @author WangSen14  * @date 2014-6-2815  * @time 下午10:56:4016  */17 public class FragmentTag extends SimpleTagSupport {18     private JspFragment fragment;19 20     public JspFragment getFragment() {21         return fragment;22     }23 24     public void setFragment(JspFragment fragment) {25         this.fragment = fragment;26     }27 28     @Override29     public void doTag() throws JspException, IOException {30         JspWriter out = getJspContext().getOut();31         out.println("<div style=‘padding:10px;border:1px solid black‘>");32         out.println("<h3>下面是动态传入的jsp片段</h3>");33         //调用 输出页面片段34         fragment.invoke(null);35         out.println("</div>");36     }37     38 }

 1     <!-- 以页面片段作为属性的标签 --> 2     <tag> 3         <name>fragment</name> 4         <tag-class>com.dev.sen.FragmentTag</tag-class> 5         <!-- 指定该标签不支持标签体 --> 6         <body-content>empty</body-content> 7         <attribute> 8             <name>fragment</name> 9             <required>true</required>10             <fragment>true</fragment>11         </attribute>12     </tag>

 1 package com.dev.sen; 2  3 import java.io.IOException; 4 import java.util.ArrayList; 5  6 import javax.servlet.jsp.JspException; 7 import javax.servlet.jsp.JspWriter; 8 import javax.servlet.jsp.tagext.DynamicAttributes; 9 import javax.servlet.jsp.tagext.SimpleTagSupport;10 /**11  * 动态属性标签12  * @author WangSen13  * @date 2014-6-2814  * @time 下午11:33:3315  */16 public class DynaAttributesTag extends SimpleTagSupport implements17         DynamicAttributes {18     // 保存属性名的集合19     private ArrayList<String> keys = new ArrayList<String>();20     // 保存属性值的集合21     private ArrayList<Object> values = new ArrayList<Object>();22 23     @Override24     public void doTag() throws JspException, IOException {25         super.doTag();26         JspWriter out = getJspContext().getOut();27         out.println("<ol>");28         for (int i = 0; i < keys.size(); i++) {29             out.println("<li>"+keys.get(i)+"="+values.get(i)+"</li>");30         }31         out.println("</ol>");32     }33 34     @Override35     public void setDynamicAttribute(String uri, String key, Object value)36             throws JspException {37         //添加属性名38         keys.add(key);39         //添加属性值40         values.add(value);41     }42 }

1     <!-- 动态属性标签 -->2     <tag>3         <name>dynimicAttr</name>4         <tag-class>com.dev.sen.DynaAttributesTag</tag-class>5         <body-content>empty</body-content>6         <!-- 设置支持动态属性 -->7         <dynamic-attributes>true</dynamic-attributes>8     </tag>

 1 package com.dev.tld; 2 /** 3  * 自定义标签方法 4  * @author WangSen 5  * @date 2014-6-29 6  * @time 下午8:09:52 7  */ 8 public class Functions { 9     /**10      * 字符翻转11      * @param text 传入的字符串12      * @return    翻转后的字符串13      */14     public static String reverse(String text){15         return new StringBuffer(text).reverse().toString();16     }17     18     /**19      * 统计字串的长度20      * @param text  待统计的字符串21      * @return    带统计字符的长度22      */23     public static int CountChar(String text){24         return text.length();25     }26 27 }

 1     <!-- 自定义函数 --> 2     <function> 3         <name>reverse</name> 4         <function-class>com.dev.tld.Functions</function-class> 5         <function-signature>java.lang.String reverse(java.lang.String)</function-signature> 6     </function> 7     <function> 8         <name>countChar</name> 9         <function-class>com.dev.tld.Functions</function-class>10         <function-signature>int countChar(java.lang.String)</function-signature>11     </function>