• j2ee [ 自定义MVC实现增删改查分页 ]

    1.配置文件 

    • web.xml文件 
    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    4.          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
    5.          version="4.0">
    6.  
    7. <!--配置中央控制器-->
    8.     <servlet>
    9.         <servlet-name>ActionServlet</servlet-name>
    10.         <servlet-class>com.zking.mvc.framework.ActionServlet</servlet-class>
    11.         <!--设置config配置文件-->
    12.         <init-param>
    13.             <param-name>config</param-name>
    14.             <param-value>/config.xml</param-value>
    15.         </init-param>
    16.     </servlet>
    17.     <servlet-mapping>
    18.         <servlet-name>ActionServlet</servlet-name>
    19.         <url-pattern>*.action</url-pattern>
    20.     </servlet-mapping>
    21. <!--配置中文过滤器-->
    22.     <filter>
    23.         <filter-name>EncodingFilter</filter-name>
    24.         <filter-class>com.jmh.utils.EncodingFilter</filter-class>
    25.     </filter>
    26.     <filter-mapping>
    27.         <filter-name>EncodingFilter</filter-name>
    28.         <url-pattern>/*</url-pattern>
    29.     </filter-mapping>
    30. </web-app>
    •  z.xml文件(自定义标签)
    1. <!DOCTYPE taglib
    2.   PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
    3.    "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
    4. <!-- 标签库描述符 -->
    5. <taglib xmlns="http://java.sun.com/JSP/TagLibraryDescriptor">
    6. 	<tlib-version>1.0</tlib-version>
    7. 	<jsp-version>1.2</jsp-version>
    8. 	<short-name>Simple Tags</short-name>
    9. 	<uri>/zking</uri>
    10. 	<tag>
    11. 		<name>page</name>
    12. 		<tag-class>com.jmh.utils.PageTag</tag-class>
    13. 		<body-content>empty</body-content>
    14. 		<attribute>
    15. 			<name>pageBean</name>
    16. 			<required>true</required>
    17. 			<rtexprvalue>true</rtexprvalue>
    18. 		</attribute>
    19. 	</tag>
    20. </taglib>
    •  config.xml文件(务必和src包放在一块儿)
    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <!-- 根目录 -->
    3. <config>
    4. <!-- 第一个action标签 -->
    5. 	<!--indexAction-->
    6. 	<action path="/indexAction" type="com.jmh.action.IndexAction">
    7. 		<forward name="failed" path="/add.jsp" redirect="false" />
    8. 		<forward name="success" path="/add.jsp" redirect="true" />
    9. 	</action>
    10. 	<!--userAction-->
    11. 	<action path="/userAction" type="com.jmh.action.UserAction">
    12. 		<forward name="failed" path="/add.jsp" redirect="false" />
    13. 		<forward name="success" path="/add.jsp" redirect="true" />
    14. 	</action>
    15. 	<!--bookAction-->
    16. 	<action path="/bookAction" type="com.jmh.action.BookAction">
    17. 		<!--跳转主页使用转发(查询全部、模糊查询)-->
    18. 		<forward name="list" path="/listBook.jsp" redirect="false" />
    19. 		<!--跳转查询全部功能使用重定向(删除)-->
    20. 		<forward name="success" path="/bookAction.action?methodName=listBook" redirect="true" />
    21. 		<!--跳转查看单个页面使用转发(查看单个)-->
    22. 		<forward name="load" path="/loadBook.jsp" redirect="false" />
    23. 		<!--跳转查看编辑页面使用转发(编辑书本信息)-->
    24. 		<forward name="edit" path="/editBook.jsp" redirect="false" />
    25. 		<!--跳转绑定数据的功能(编辑书本成功之后)-->
    26. 		<forward name="update" path="/bookAction.action?methodName=listBook" redirect="true" />
    27. 	</action>
    28. </config>

     2.实体类

    • Book.java
    1. package com.jmh.entity;
    2.  
    3. import java.io.Serializable;
    4.  
    5. /**
    6.  * 书本对象
    7.  */
    8. public class Book implements Serializable {
    9.     private Integer book_id;//书本编号
    10.     private String book_name;//书本名称
    11.     private float price;//书本价格
    12.  
    13.     public Book(Integer book_id, String book_name, float price) {
    14.         this.book_id = book_id;
    15.         this.book_name = book_name;
    16.         this.price = price;
    17.     }
    18.  
    19.     public Book() {
    20.     }
    21.  
    22.     public Integer getBook_id() {
    23.         return book_id;
    24.     }
    25.  
    26.     public String getBook_name() {
    27.         return book_name;
    28.     }
    29.  
    30.     public float getPrice() {
    31.         return price;
    32.     }
    33.  
    34.     public void setBook_id(Integer book_id) {
    35.         this.book_id = book_id;
    36.     }
    37.  
    38.     public void setBook_name(String book_name) {
    39.         this.book_name = book_name;
    40.     }
    41.  
    42.     public void setPrice(float price) {
    43.         this.price = price;
    44.     }
    45.  
    46.     @Override
    47.     public String toString() {
    48.         return "Book{" +
    49.                 "book_id=" + book_id +
    50.                 ", book_name='" + book_name + '\'' +
    51.                 ", price=" + price +
    52.                 '}';
    53.     }
    54. }

     3.dao类

    • BookDao.java 
    1. package com.jmh.dao;
    2.  
    3. import com.jmh.base.BaseDao;
    4. import com.jmh.entity.Book;
    5. import com.jmh.utils.CommonUtils;
    6. import com.jmh.utils.PageBean;
    7. import com.jmh.utils.StringUtils;
    8.  
    9. import java.sql.ResultSet;
    10. import java.sql.SQLException;
    11. import java.util.List;
    12.  
    13. public class BookDao extends BaseDao<Book> {
    14.     /**
    15.      * 分页查询的方法
    16.      * @param b 书本对象
    17.      * @param pb 工具类
    18.      * @return 结果集合
    19.      */
    20.     public List<Book> listBook(Book b, PageBean pb){
    21.         //普通查询语句
    22.         String sql="select book_id,book_name,price from tb_book where 1=1";
    23.         //符合模糊查询语句
    24.         if(StringUtils.isNotBlank(b.getBook_name())){//书本名称不等于空
    25.             sql+=" and book_name like '%"+b.getBook_name()+"%' ";
    26.         }
    27.         //返回===调用父类的查询方法
    28.         return this.executeQuery(sql, pb, new CallBack() {
    29.             @Override
    30.             public List forEachRs(ResultSet rs) throws SQLException {
    31.                 return CommonUtils.toList(rs,Book.class);
    32.             }
    33.         });
    34.     }
    35.  
    36.     /**
    37.      * 新增书本方法
    38.      * @param b 书本对象
    39.      */
    40.     public void insertBook(Book b){
    41.         //编写增加书本的sql语句
    42.         String sql="insert into tb_book " +
    43.                 "(book_name,price) values(?,?)";
    44.         this.executeUpdate(sql,new Object[]{
    45.                 b.getBook_name(),
    46.                 b.getPrice()
    47.         });
    48.     }
    49.  
    50.     /**
    51.      * 根据书本编号删除的方法
    52.      * @param b 书本对象
    53.      */
    54.     public void deleteBook(Book b){
    55.         //编写根据书本编号删除的sql语句
    56.         String sql="delete from tb_book where book_id=?";
    57.         this.executeUpdate(sql,new Object[]{
    58.                 b.getBook_id()
    59.         });
    60.     }
    61.  
    62.     /**
    63.      * 根据书本编号编辑书本
    64.      * @param b 书本编号
    65.      */
    66.     public void updateBook(Book b){
    67.         //编写根据书本编号编辑书本的sql语句
    68.         String sql="update tb_book set book_name=?,price=? where book_id=?";
    69.         this.executeUpdate(sql,new Object[]{
    70.                 b.getBook_name(),
    71.                 b.getPrice(),
    72.                 b.getBook_id()
    73.         });
    74.     }
    75.  
    76.     /**
    77.      * 根据书本编号查询书本单个信息
    78.      * @param b 书本信息
    79.      * @return 书本单个信息
    80.      */
    81.     public Book loadBook(Book b){
    82.         //编写根据书本编号查询书本信息的sql语句
    83.         String sql="select book_id,book_name,price from tb_book where book_id="+b.getBook_id();
    84.        List<Book> listBook= this.executeQuery(sql, null, new CallBack() {
    85.             @Override
    86.             public List forEachRs(ResultSet rs) throws SQLException {
    87.                 return CommonUtils.toList(rs,Book.class);
    88.             }
    89.         });
    90.         return listBook.get(0);
    91.     }
    92.  
    93. }

     4.base类

    • BaseDao.java 
    1. package com.jmh.base;
    2.  
    3. import java.sql.*;
    4. import java.util.List;
    5.  
    6. import com.jmh.entity.Book;
    7. import com.jmh.utils.DBHelper;
    8. import com.jmh.utils.PageBean;
    9. import com.jmh.utils.StringUtils;
    10.  
    11. public class BaseDao<K> {
    12. 	/**
    13. 	 * 回调函数 用于遍历rs结果集
    14. 	 * @author Administrator
    15. 	 *
    16. 	 * @param <T>
    17. 	 */
    18. 	public static interface CallBack<T> {
    19. 		public List<T> forEachRs(ResultSet rs) throws SQLException;
    20. 	}
    21. 	
    22. 	//带有分页的模糊查询方法
    23. 	public List<K> executeQuery(String sql,PageBean pageBean,CallBack callBack){
    24. 		Connection conn = null;
    25. 		PreparedStatement pst = null;
    26. 		ResultSet rs = null;
    27. 		try {
    28. 			conn = DBHelper.getConnection();
    29. 			//查询总记录数
    30. 			if(null!=pageBean && pageBean.isPagination()) {
    31. 				String countSql = this.getCountSql(sql);
    32. 				pst = conn.prepareStatement(countSql);
    33. 				rs = pst.executeQuery();
    34. 				if(rs.next()) {
    35. 					Object obj = rs.getInt(1);
    36. 					pageBean.setTotal(obj.toString());
    37. 				}
    38. 				DBHelper.close(null, pst, rs);
    39. 			}
    40. 			if(null!=pageBean && pageBean.isPagination()) {
    41. 				sql = this.getPageSql(sql,pageBean);
    42. 			}
    43. 			
    44. 			pst = conn.prepareStatement(sql);
    45. 			rs = pst.executeQuery();
    46. 			
    47. 			
    48. 			return callBack.forEachRs(rs);
    49. 			
    50. 		} catch (Exception e) {
    51. 			throw new RuntimeException(e);
    52. 		}finally {
    53. 			DBHelper.close(conn, pst, rs);
    54. 		}
    55. 		
    56. 		
    57. 		
    58. 		
    59. 	}
    60. 	/**
    61. 	 * 得到总记录数的sql
    62. 	 * @param sql
    63. 	 * @return
    64. 	 */
    65. 	private String getCountSql(String sql) {
    66. 		String countSql = "SELECT COUNT(*) FROM ("+sql+") t1";
    67. 		return countSql;
    68. 	}
    69. 	
    70. 	/**
    71. 	 * 得到分页的sql
    72. 	 * @param sql
    73. 	 * @param pageBean
    74. 	 * @return
    75. 	 */
    76. 	private String getPageSql(String sql,PageBean pageBean) {
    77. 		String pageSql = sql + " LIMIT "+pageBean.getStartIndex()+","+pageBean.getRows();
    78. 		return pageSql;
    79. 		
    80. 		
    81. 	}
    82.  
    83. 	/**
    84. 	 * 方便增删改的方法
    85. 	 * @param sql
    86. 	 * @param params
    87. 	 */
    88. 	public void executeUpdate(String sql,Object[] params) {
    89. 		Connection conn=null;
    90. 		PreparedStatement stmt=null;
    91. 		try {
    92. 			conn=DBHelper.getConnection();
    93. 			stmt=conn.prepareStatement(sql);
    94. 			ParameterMetaData metaData = stmt.getParameterMetaData();
    95. 			for (int i = 0; i < metaData.getParameterCount(); i++) {
    96. 				stmt.setObject(i+1, params[i]);
    97. 			}
    98. 			int i = stmt.executeUpdate();
    99. 			if(i<1)
    100. 				throw new RuntimeException("执行失败，影响行数为0！");
    101. 		} catch (Exception e) {
    102. 			e.printStackTrace();
    103. 			throw new RuntimeException(e);
    104. 		} finally {
    105. 			DBHelper.close(conn, stmt, null);
    106. 		}
    107. 	}
    108. 	
    109. }

     5.utils工具类

    • config.properties 
    1. #mysql
    2. driver=com.mysql.jdbc.Driver
    3. url=jdbc:mysql://localhost:3306/填写自己的数据库名称?useUnicode=true&characterEncoding=UTF-8
    4. user=填写自己的数据库登录账号
    5. pwd=填写自己的数据库登录密码
    •  DBHelper.java（这里不需要动，如果数据库有更改，更改上方文件即可）
    1. package com.jmh.utils;
    2.  
    3. import java.io.InputStream;
    4. import java.sql.Connection;
    5. import java.sql.DriverManager;
    6. import java.sql.ResultSet;
    7. import java.sql.SQLException;
    8. import java.sql.Statement;
    9. import java.util.Properties;
    10.  
    11. /**
    12.  * 提供了一组获得或关闭数据库对象的方法
    13.  * 
    14.  */
    15. public class DBHelper {
    16. 	private static String driver;
    17. 	private static String url;
    18. 	private static String user;
    19. 	private static String password;
    20.  
    21. 	static {// 静态块执行一次，加载 驱动一次
    22. 		try {
    23. 			InputStream is = DBHelper.class
    24. 					.getResourceAsStream("config.properties");
    25.  
    26. 			Properties properties = new Properties();
    27. 			properties.load(is);
    28.  
    29. 			driver = properties.getProperty("driver");
    30. 			url = properties.getProperty("url");
    31. 			user = properties.getProperty("user");
    32. 			password = properties.getProperty("pwd");
    33.  
    34. 			Class.forName(driver);
    35. 		} catch (Exception e) {
    36. 			e.printStackTrace();
    37. 			throw new RuntimeException(e);
    38. 		}
    39. 	}
    40.  
    41. 	/**
    42. 	 * 获得数据连接对象
    43. 	 * 
    44. 	 * @return
    45. 	 */
    46. 	public static Connection getConnection() {
    47. 		try {
    48. 			Connection conn = DriverManager.getConnection(url, user, password);
    49. 			return conn;
    50. 		} catch (SQLException e) {
    51. 			e.printStackTrace();
    52. 			throw new RuntimeException(e);
    53. 		}
    54. 	}
    55.  
    56. 	public static void close(ResultSet rs) {
    57. 		if (null != rs) {
    58. 			try {
    59. 				rs.close();
    60. 			} catch (SQLException e) {
    61. 				e.printStackTrace();
    62. 				throw new RuntimeException(e);
    63. 			}
    64. 		}
    65. 	}
    66.  
    67. 	public static void close(Statement stmt) {
    68. 		if (null != stmt) {
    69. 			try {
    70. 				stmt.close();
    71. 			} catch (SQLException e) {
    72. 				e.printStackTrace();
    73. 				throw new RuntimeException(e);
    74. 			}
    75. 		}
    76. 	}
    77.  
    78. 	public static void close(Connection conn) {
    79. 		if (null != conn) {
    80. 			try {
    81. 				conn.close();
    82. 			} catch (SQLException e) {
    83. 				e.printStackTrace();
    84. 				throw new RuntimeException(e);
    85. 			}
    86. 		}
    87. 	}
    88.  
    89. 	public static void close(Connection conn, Statement stmt, ResultSet rs) {
    90. 		close(rs);
    91. 		close(stmt);
    92. 		close(conn);
    93. 	}
    94.  
    95. 	public static boolean isOracle() {
    96. 		return "oracle.jdbc.driver.OracleDriver".equals(driver);
    97. 	}
    98.  
    99. 	public static boolean isSQLServer() {
    100. 		return "com.microsoft.sqlserver.jdbc.SQLServerDriver".equals(driver);
    101. 	}
    102. 	
    103. 	public static boolean isMysql() {
    104. 		return "com.mysql.jdbc.Driver".equals(driver);
    105. 	}
    106.  
    107. 	public static void main(String[] args) {
    108. 		Connection conn = DBHelper.getConnection();
    109. 		DBHelper.close(conn);
    110. 		System.out.println("isOracle：" + isOracle());
    111. 		System.out.println("isSQLServer：" + isSQLServer());
    112. 		System.out.println("isMysql：" + isMysql());
    113. 		System.out.println("数据库连接(关闭)成功");
    114. 	}
    115. }
    •  CommonUtils.java
    1. package com.jmh.utils;
    2.  
    3. import java.lang.reflect.Field;
    4. import java.lang.reflect.Method;
    5. import java.sql.ResultSet;
    6. import java.sql.ResultSetMetaData;
    7. import java.util.ArrayList;
    8. import java.util.HashMap;
    9. import java.util.List;
    10. import java.util.Map;
    11.  
    12. import javax.servlet.http.HttpServletResponse;
    13.  
    14.  
    15.  
    16. public class CommonUtils {
    17. 	
    18. 	
    19. 	
    20. 	/**
    21. 	 * 根据ResultSet数据集，利用反射机制动态赋值并返回List<T>
    22. 	 * @param rs ResultSet数据集
    23. 	 * @param clazz 实体类对象
    24. 	 * @return 返回List实体集合
    25. 	 * @throws Exception
    26. 	 */
    27. 	public static <T> List<T> toList(ResultSet rs,Class<T> clazz){
    28. 		//定义实体集合
    29. 		List<T> lst=new ArrayList<T>();
    30. 		try {
    31. 			//获取ResultSet的metadata列信息
    32. 			ResultSetMetaData metaData = rs.getMetaData();
    33. 			//获取对象属性集合
    34. 			Field[] fields=clazz.getDeclaredFields();
    35. 			//循环ResultSet
    36. 			while(rs.next()) {
    37. 				//反射机制实例化
    38. 				T obj = clazz.newInstance();
    39. 				for (int i = 0; i < metaData.getColumnCount(); i++) {
    40. 					//获取列名
    41. 					String columnName=metaData.getColumnLabel(i+1).toUpperCase();
    42. 					for (Field field : fields) {
    43. 						//判断属性名与列名是否相同
    44. 						if(field.getName().toUpperCase().equals(columnName)) {
    45. 							//获取属性对应的set方法名，方法名首字母大写
    46. 							String methodName="set"+field.getName().substring(0, 1).toUpperCase()+field.getName().substring(1);
    47. 							//获取属性对应的set方法
    48. 							Method method = obj.getClass().getDeclaredMethod(methodName, field.getType());
    49. 							//设置访问权限
    50. 							method.setAccessible(true);
    51. 							//执行set方法，将数据存储到对象中的相应属性中
    52. 							method.invoke(obj, rs.getObject(columnName));
    53. 							break;
    54. 						}
    55. 					}
    56. 				}
    57. 				lst.add(obj);
    58. 			}
    59. 		}catch(Exception e) {
    60. 			e.printStackTrace();
    61. 		}
    62. 		return lst;
    63. 	}
    64. 	
    65. 	/**
    66. 	 * 多表查询时返回结果集,利用反射机制赋值 
    67. 	 * @param rs
    68. 	 * @return 返回List<Map<String,Object>>
    69. 	 * @throws Exception
    70. 	 */
    71. 	public static List<Map<String,Object>> toList(ResultSet rs){
    72. 		//定义实体集合
    73. 		List<Map<String,Object>> lst=new ArrayList<Map<String,Object>>();
    74. 		try {
    75. 			//获取ResultSet的metadata列信息	
    76. 			ResultSetMetaData metaData = rs.getMetaData();
    77. 			Map<String,Object> set=null;
    78. 			while(rs.next()) {
    79. 				set=new HashMap<String,Object>();
    80. 				for (int i = 0; i < metaData.getColumnCount(); i++) {
    81. 					String columnName=metaData.getColumnLabel(i+1);
    82. 					set.put(columnName, rs.getObject(columnName));
    83. 				}
    84. 				lst.add(set);
    85. 			}
    86. 		}catch(Exception e) {
    87. 			e.printStackTrace();
    88. 		}
    89. 		return lst;
    90. 	}
    91. }
    •  EncodingFilter.java
    1. package com.jmh.utils;
    2.  
    3. import java.io.IOException;
    4. import java.util.Iterator;
    5. import java.util.Map;
    6. import java.util.Set;
    7.  
    8. import javax.servlet.Filter;
    9. import javax.servlet.FilterChain;
    10. import javax.servlet.FilterConfig;
    11. import javax.servlet.ServletException;
    12. import javax.servlet.ServletRequest;
    13. import javax.servlet.ServletResponse;
    14. import javax.servlet.http.HttpServletRequest;
    15. import javax.servlet.http.HttpServletResponse;
    16.  
    17. /**
    18.  * 中文乱码处理
    19.  * 
    20.  */
    21. public class EncodingFilter implements Filter {
    22.  
    23. 	private String encoding = "UTF-8";// 默认字符集
    24.  
    25. 	public EncodingFilter() {
    26. 		super();
    27. 	}
    28.  
    29. 	public void destroy() {
    30. 	}
    31.  
    32. 	public void doFilter(ServletRequest request, ServletResponse response,
    33. 			FilterChain chain) throws IOException, ServletException {
    34. 		HttpServletRequest req = (HttpServletRequest) request;
    35. 		HttpServletResponse res = (HttpServletResponse) response;
    36.  
    37. 		// 中文处理必须放到 chain.doFilter(request, response)方法前面
    38. 		res.setContentType("text/html;charset=" + this.encoding);
    39. 		if (req.getMethod().equalsIgnoreCase("post")) {
    40. 			req.setCharacterEncoding(this.encoding);
    41. 		} else {
    42. 			Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合
    43. 			Set set = map.keySet();// 取出所有参数名
    44. 			Iterator it = set.iterator();
    45. 			while (it.hasNext()) {
    46. 				String name = (String) it.next();
    47. 				String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]
    48. 				for (int i = 0; i < values.length; i++) {
    49. 					values[i] = new String(values[i].getBytes("ISO-8859-1"),
    50. 							this.encoding);
    51. 				}
    52. 			}
    53. 		}
    54.  
    55. 		chain.doFilter(request, response);
    56. 	}
    57.  
    58. 	public void init(FilterConfig filterConfig) throws ServletException {
    59. 		String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集
    60. 		if (null != s && !s.trim().equals("")) {
    61. 			this.encoding = s.trim();
    62. 		}
    63. 	}
    64.  
    65. }
    •  PageBean.java
    1. package com.jmh.utils;
    2.  
    3. import java.util.Map;
    4.  
    5. import javax.servlet.http.HttpServletRequest;
    6.  
    7. public class PageBean {
    8. 	
    9. 	private Integer page =1; //页码 默认为1
    10. 	
    11. 	private Integer rows = 10; //页大小 默认为10
    12. 	
    13. 	private Integer total =0;  // 总记录数
    14. 	
    15. 	private boolean pagination=true; //是否分页 默认为false
    16. 	
    17. 	
    18. 	private String url;  //请求路径 
    19. 	
    20. 	
    21. 	private Map<String,String[]> map; //请求的参数集合
    22.  
    23. 	public PageBean() {
    24. 		super();
    25. 	}
    26.  
    27. 	public Integer getPage() {
    28. 		return page;
    29. 	}
    30.  
    31. 	public void setPage(Integer page) {
    32. 		this.page = page;
    33. 	}
    34.  
    35. 	public Integer getRows() {
    36. 		return rows;
    37. 	}
    38.  
    39. 	public void setRows(Integer rows) {
    40. 		this.rows = rows;
    41. 	}
    42.  
    43. 	public Integer getTotal() {
    44. 		return total;
    45. 	}
    46.  
    47. 	public void setTotal(Integer total) {
    48. 		this.total = total;
    49. 	}
    50. 	
    51. 	public void setTotal(String total) {
    52. 		this.total = Integer.parseInt(total);
    53. 	}
    54.  
    55. 	public boolean isPagination() {
    56. 		return pagination;
    57. 	}
    58.  
    59. 	public void setPagination(boolean pagination) {
    60. 		this.pagination = pagination;
    61. 	}
    62.  
    63. //	@Override
    64. //	public String toString() {
    65. //		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
    66. //	}
    67. 	
    68. 	public int getStartIndex() {
    69. 		return (this.page-1)*this.rows;
    70. 		
    71. 		
    72. 	}
    73. 	
    74.  
    75. 	@Override
    76. 	public String toString() {
    77. 		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination
    78. 				+ ", url=" + url + ", map=" + map + "]";
    79. 	}
    80.  
    81. 	public String getUrl() {
    82. 		return url;
    83. 	}
    84.  
    85. 	public void setUrl(String url) {
    86. 		this.url = url;
    87. 	}
    88.  
    89. 	public Map<String, String[]> getMap() {
    90. 		return map;
    91. 	}
    92.  
    93. 	public void setMap(Map<String, String[]> map) {
    94. 		this.map = map;
    95. 	}
    96. 	
    97. 	
    98. 	public void setPage(String page) {
    99. 		if(null!=page && !"".equals(page)) {
    100. 			this.page = Integer.parseInt(page);
    101. 		}
    102. 	}
    103. 	
    104. 	public void setRows(String rows) {
    105. 		if(null!=rows && !"".equals(rows)) {
    106. 			this.rows = Integer.parseInt(rows);
    107. 		}
    108. 	}
    109. 	
    110. 	
    111. 	
    112. 	public void setPagination(String pagination) {
    113. 		if(null!=pagination && !"".equals(pagination)) {
    114. 			this.pagination = Boolean.parseBoolean(pagination);
    115. 		}
    116. 	}
    117. 	/**
    118. 	 * 对pageBean初始化
    119. 	 * @param req
    120. 	 */
    121. 	public void setRequest(HttpServletRequest req) {
    122. 		
    123. 		//获取页面上的参数
    124. 		String page = req.getParameter("page");
    125. 		String rows = req.getParameter("rows");
    126. 		String pagination = req.getParameter("pagination");
    127. 		
    128. 		//设置参数
    129. 		
    130. 		this.setPage(page);
    131. 		this.setRows(rows);
    132. 		this.setPagination(pagination);
    133. 		
    134. 		this.setUrl(req.getRequestURI());
    135. 		this.setMap(req.getParameterMap());
    136. 		
    137. 	}
    138. 	
    139. 	/**
    140. 	 * 得到最大的页码数
    141. 	 * @return
    142. 	 */
    143. 	public int getMaxPage() {
    144. 		int maxPage = this.total / this.rows;
    145. 		if(this.total%this.rows!=0) {
    146. 			maxPage++;
    147. 		}
    148. 		return maxPage;
    149. 	}
    150. 	
    151. 	/**
    152. 	 * 得到下一页的页码
    153. 	 * @return
    154. 	 */
    155. 	public int getNextPage() {
    156. 		int nextPage = this.page+1;
    157. 		if(nextPage>=getMaxPage()) {
    158. 			nextPage = getMaxPage();
    159. 		}
    160. 		return nextPage;
    161. 	}
    162. 	
    163. 	/**
    164. 	 * 得到上一页的页码
    165. 	 * @return
    166. 	 */
    167. 	public int getPreviousPage() {
    168. 		int previousPage = this.page -1;
    169. 		if(previousPage<1) {
    170. 			 previousPage =1;
    171. 		}
    172. 		return previousPage;
    173. 	}
    174. 	
    175. }
    •  PageTag.java
    1. package com.jmh.utils;
    2.  
    3. import java.io.IOException;
    4. import java.util.Map;
    5. import java.util.Map.Entry;
    6. import java.util.Set;
    7.  
    8. import javax.servlet.jsp.JspException;
    9. import javax.servlet.jsp.JspWriter;
    10. import javax.servlet.jsp.tagext.BodyTagSupport;
    11.  
    12. import com.jmh.utils.PageBean;
    13.  
    14.  
    15.  
    16. public class PageTag extends BodyTagSupport {
    17. 	private PageBean pageBean;
    18.  
    19. 	public PageTag() {
    20. 		super();
    21. 	}
    22.  
    23. 	public PageBean getPageBean() {
    24. 		return pageBean;
    25. 	}
    26.  
    27. 	public void setPageBean(PageBean pageBean) {
    28. 		this.pageBean = pageBean;
    29. 	}
    30.  
    31. 	@Override
    32. 	public int doStartTag() throws JspException {
    33. 		JspWriter out = pageContext.getOut();
    34. 		try {
    35. 			out.println(toHtml());
    36. 		} catch (Exception e) {
    37. 			throw new RuntimeException(e);
    38. 		}
    39. 		return super.doStartTag();
    40. 	}
    41. 	
    42. 	
    43. 	private String toHtml() {
    44. 		//pageBean为空或者 不分页
    45. 		if(null==pageBean || !pageBean.isPagination()) {
    46. 			return "";
    47. 		}
    48. 		StringBuilder sb = new StringBuilder();
    49. 		//拼接form表单
    50. 		/*<form action="${pageBean.url}" method="post" id="pageBeanForm">
    51. 		<!-- 设置页码 -->
    52. 		<input type="hidden" name="page"/>
    53. 	    <!-- 参数列表 -->
    54. 		</form>*/
    55. 		sb.append("<form action=\""+pageBean.getUrl()+"\" method=\"post\" id=\"pageBeanForm\">");
    56. 		sb.append("<input type=\"hidden\" name=\"page\"/>");
    57. 		
    58. 		//参数列表
    59. 		
    60. 		Map<String, String[]> map = pageBean.getMap();
    61. 		String name =null;
    62. 		String[] values = null;
    63. 		// bookName = '不短命'  hobby="篮球"  hobby="足球" page="2"
    64. 		Set<Entry<String, String[]>> entrySet = map.entrySet();
    65. 		for (Entry<String, String[]> entry : entrySet) {
    66. 			name = entry.getKey();
    67. 			if(name.equals("page")) {
    68. 				continue;
    69. 			}
    70. 			values = entry.getValue();
    71. 			for (String value : values) {
    72. 				
    73. 				//<input type="hidden" name="bookName" valu="不短命"/>
    74. 				//<input type="hidden" name="hobby" valu="篮球"/>
    75. 				//<input type="hidden" name="hobby" valu="足球"/>
    76. 				sb.append("<input type=\"hidden\" name=\""+name+"\" value=\""+value+"\"/>");
    77. 			}
    78. 		}
    79. 		sb.append("</form>");
    80. 		
    81. 		
    82. 		//拼接div部分
    83. 		/*<div style="width:100%;text-align: right;">
    84. 		第几页/总共多少页,共多少条记录 
    85. 		<a href="javascript:gotoPage(1)">首页</a>&nbsp;
    86. 		<a href="javascript:gotoPage(${pageBean.getPreviousPage()})">上一页</a>&nbsp;
    87. 		<a href="javascript:gotoPage(${pageBean.getNextPage()})">下一页</a>&nbsp;
    88. 		<a href="javascript:gotoPage(${pageBean.getMaxPage()})">末页</a>&nbsp;
    89. 		<input type="text" id="skipPage" style="width:30px;"/>&nbsp;
    90. 		<a href="javascript:skipPage(${pageBean.getMaxPage()})">GO</a>
    91. 	
    92. 	
    93. 	
    94. 		</div>*/
    95. 		sb.append("<div style=\"width:100%;text-align: right;\">");
    96. 		sb.append("第"+pageBean.getPage()+"页/总共"+pageBean.getMaxPage()+"页,共"+pageBean.getTotal()+"条记录 ");
    97. 		
    98. 		//首页  上一页
    99. 		if(pageBean.getPage()!=1) {
    100. 			sb.append("<a href=\"javascript:gotoPage(1)\">首页</a>&nbsp;\r\n" + 
    101. 					"		<a href=\"javascript:gotoPage("+pageBean.getPreviousPage()+")\">上一页</a>&nbsp;");
    102. 		}else {
    103. 			sb.append("<a>首页</a>&nbsp;<a>上一页</a>&nbsp;");
    104. 		}
    105. 		
    106. 		
    107. 		//末页 下一页
    108. 		
    109. 		if(pageBean.getPage()!=pageBean.getMaxPage()) {
    110. 			sb.append("<a href=\"javascript:gotoPage("+pageBean.getNextPage()+")\">下一页</a>&nbsp;\r\n" + 
    111. 					"		<a href=\"javascript:gotoPage("+pageBean.getMaxPage()+")\">末页</a>&nbsp;");
    112. 		}else {
    113. 			sb.append("<a>下一页</a>&nbsp;<a>末页</a>&nbsp;");
    114. 		}
    115. 		
    116. 		//跳转页
    117. 		sb.append("<input type=\"text\" id=\"skipPage\" style=\"width:30px;\"/>&nbsp;");
    118. 		sb.append("<a href=\"javascript:skipPage()\">GO</a>");
    119. 		sb.append("</div>");
    120. 		
    121. 		//拼接js
    122. 		/*<script type="text/javascript">
    123. 		function gotoPage(page) {
    124. 			document.getElementById('pageBeanForm').page.value=page;
    125. 			document.getElementById('pageBeanForm').submit();
    126. 		}
    127. 		function skipPage(maxPage) {
    128. 			var page = document.getElementById('skipPage').value;
    129. 			if(isNaN(page) || page<1 || page>maxPage){
    130. 				alert("请输入1-"+maxPage+"的数字");
    131. 				return false;
    132. 			}
    133. 			gotoPage(page);
    134. 		}
    135. 		</script>*/
    136. 		
    137. 		sb.append("<script type=\"text/javascript\">\r\n" + 
    138. 				"	function gotoPage(page) {\r\n" + 
    139. 				"		document.getElementById('pageBeanForm').page.value=page;\r\n" + 
    140. 				"		document.getElementById('pageBeanForm').submit();\r\n" + 
    141. 				"	}\r\n" + 
    142. 				"	function skipPage() {\r\n" + 
    143. 				"		var page = document.getElementById('skipPage').value;\r\n" + 
    144. 				"		if(isNaN(page) || page<1 || page>"+pageBean.getMaxPage()+"){\r\n" + 
    145. 				"			alert(\"请输入1-\"+"+pageBean.getMaxPage()+"+\"的数字\");\r\n" + 
    146. 				"			return false;\r\n" + 
    147. 				"		}\r\n" + 
    148. 				"		gotoPage(page);\r\n" + 
    149. 				"	}\r\n" + 
    150. 				"\r\n" + 
    151. 				"</script>");
    152. 		
    153. 		
    154. 		return sb.toString();
    155. 	}
    156. 	
    157. 	
    158. }
    •  StringUtils.java
    1. package com.jmh.utils;
    2.  
    3. public class StringUtils {
    4. 	// 私有的构造方法，保护此类不能在外部实例化
    5. 	private StringUtils() {
    6. 	}
    7.  
    8. 	/**
    9. 	 * 如果字符串等于null或去空格后等于""，则返回true，否则返回false
    10. 	 * 
    11. 	 * @param s
    12. 	 * @return
    13. 	 */
    14. 	public static boolean isBlank(String s) {
    15. 		boolean b = false;
    16. 		if (null == s || s.trim().equals("")) {
    17. 			b = true;
    18. 		}
    19. 		return b;
    20. 	}
    21. 	
    22. 	/**
    23. 	 * 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
    24. 	 * 
    25. 	 * @param s
    26. 	 * @return
    27. 	 */
    28. 	public static boolean isNotBlank(String s) {
    29. 		return !isBlank(s);
    30. 	}
    31.  
    32. }

     除了还有一些核心代码作者导成了jar方便使用，如有需要私我即可.然后。。。就到这里啦？

     

     

    效果图如下：                                         

     

     

     

     

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  • 原文地址：https://blog.csdn.net/m0_63300795/article/details/125632037