Java-KGLI工具類總結(jié)

1、C3p0 連接池 DB工具類：JDBCUtils :package cn.kgli.utils;import java.io.InputStream;import java.lang.reflect.Field;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.SQLException;import java.sq

2、l.Statement;import java.util.ArrayList;import java.util.List;import java.util.Properties;imporboPooledDataSource;public class JdbcUtils private static ComboPooledDataSource ds = null;statictry/*ds = new ComboPooledDataSource();ds.setDriverClass("com.mysql.jdbc.Driver");ds.setJdbcUrl("

3、jdbc:mysql:/localhost:3306/day16");ds.setUser("root");ds.setPassword("root");ds.setInitialPoolSize(10);ds.setMinPoolSize(5);ds.setMaxPoolSize(20);*/ds = new ComboPooledDataSource();catch (Exception e) throw new ExceptionInInitializerError(e);public static Connection getConne

4、ction() throws SQLExceptionreturn ds.getConnection();public static void release(Connection conn,Statement st,ResultSet rs)if(rs!=null)tryrs.close();catch (Exception e) e.printStackTrace();rs = null;if(st!=null)tryst.close();catch (Exception e) e.printStackTrace();if(conn!=null)tryconn.close();catch

5、(Exception e) e.printStackTrace();/替換dao中的增刪改方法public static void update(String sql,Object params) throws SQLExceptionConnection conn = null;PreparedStatement st = null;ResultSet rs = null;tryconn = getConnection();st = conn.prepareStatement(sql);for(int i=0;i<params.length;i+)st.setObject(i+1, p

6、aramsi);st.executeUpdate();finallyrelease(conn, st, rs);/替換所有dao中的查詢 策略模式public static Object query(String sql,Object params,ResultSetHandler rsh) throws SQLExceptionConnection conn = null;PreparedStatement st = null;ResultSet rs = null;tryconn = getConnection();st = conn.prepareStatement(sql);for(i

7、nt i=0;i<params.length;i+)st.setObject(i+1, paramsi);rs = st.executeQuery();return rsh.handler(rs);finallyrelease(conn, st, rs);JDBCUtills_dbcp.java:package cn.kgli.utils;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.

8、SQLException;import java.sql.Statement;import java.util.Properties;import javax.sql.DataSource;import mons.dbcp.BasicDataSourceFactory;public class JdbcUtils_DBCP private static DataSource ds = null;statictryInputStream in = JdbcUtils_DBCP.class.getClassLoader().getResourceAsStream("dbcpconfig.

9、properties");Properties prop = new Properties();prop.load(in);BasicDataSourceFactory factory = new BasicDataSourceFactory();ds = factory.createDataSource(prop);System.out.println(ds);catch (Exception e) throw new ExceptionInInitializerError(e);public static Connection getConnection() throws SQL

10、Exceptionreturn ds.getConnection();public static void release(Connection conn,Statement st,ResultSet rs)if(rs!=null)tryrs.close();catch (Exception e) e.printStackTrace();rs = null;if(st!=null)tryst.close();catch (Exception e) e.printStackTrace();if(conn!=null)tryconn.close();catch (Exception e) e.pr

11、intStackTrace();/BeanHandler.javapackage cn.kgli.utils;import java.lang.reflect.Field;import java.sql.ResultSet;import java.sql.ResultSetMetaData;public class BeanHandler implements ResultSetHandler private Class clazz;public BeanHandler(Class clazz)this.clazz = clazz;public Object handler(ResultSet

12、 rs) tryif(!rs.next()return null;Object bean = clazz.newInstance();ResultSetMetaData metadata = rs.getMetaData();int columnCount = metadata.getColumnCount(); /得到結(jié)果集中有幾列數(shù)據(jù)for(int i=0;i<columnCount;i+)String coulmnName = metadata.getColumnName(i+1); /得到每列的列名Object coulmnData = rs.getObject(i+1);Fie

13、ld f = clazz.getDeclaredField(coulmnName);/反射出類上列名對應(yīng)的屬性f.setAccessible(true);f.set(bean, coulmnData);return bean;catch (Exception e) throw new RuntimeException(e);BeanListHandler.javapackage cn.kgli.utils;import java.lang.reflect.Field;import java.sql.ResultSet;import java.sql.ResultSetMetaData;impo

14、rt java.util.ArrayList;import java.util.List;public class BeanListHandler implements ResultSetHandler private Class clazz;public BeanListHandler(Class clazz)this.clazz = clazz;public Object handler(ResultSet rs) tryList list = new ArrayList();while(rs.next()Object bean = clazz.newInstance();ResultSe

15、tMetaData metadata = rs.getMetaData();int count = metadata.getColumnCount();for(int i=0;i<count;i+)String name = metadata.getColumnName(i+1);Object value = rs.getObject(name);Field f = bean.getClass().getDeclaredField(name);f.setAccessible(true);f.set(bean, value);list.add(bean);return list.size(

16、)>0?list:null;catch (Exception e) throw new RuntimeException(e);防止表單重復(fù)提交：攔截注冊頁面 加上session token package cn.kgli.servlet;import java.io.IOException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.Random;import javax.servlet.ServletException;import

17、javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import sun.misc.BASE64Encoder;public class FormServlet extends HttpServlet public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOE

18、xception String token = TokenProccessor.getInstance().makeToken();request.getSession().setAttribute("token", token); /在服務(wù)器端保存隨機(jī)數(shù)request.getRequestDispatcher("/form.jsp").forward(request, response);public void doPost(HttpServletRequest request, HttpServletResponse response)throws

19、ServletException, IOException doGet(request, response);class TokenProccessor/* *單態(tài)設(shè)計(jì)模式（保證類的對象在內(nèi)存中只有一個(gè)） *1、把類的構(gòu)造函數(shù)私有 *2、自己創(chuàng)建一個(gè)類的對象 *3、對外提供一個(gè)公共的方法，返回類的對象 * */private TokenProccessor()private static final TokenProccessor instance = new TokenProccessor();public static TokenProccessor getInstance()return

20、 instance;public String makeToken() /checkException/ 7346734837483 834u938493493849384 43434384String token = (System.currentTimeMillis() + new Random().nextInt(999999999) + ""/數(shù)據(jù)指紋 128位長 16個(gè)字節(jié) md5try MessageDigest md = MessageDigest.getInstance("md5");byte md5 = md.digest(token.

21、getBytes();/base64編碼-任意二進(jìn)制編碼明文字符 adfsdfsdfsfBASE64Encoder encoder = new BASE64Encoder();return encoder.encode(md5); catch (NoSuchAlgorithmException e) throw new RuntimeException(e);<% page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTM

22、L PUBLIC "-/W3C/DTD HTML 4.01 Transitional/EN"><html> <head> <title>My JSP 'form.jsp' starting page</title> </head> <body> <form action="/day08/servlet/DoFormServlet" method="post"> <input type="hidden" n

23、ame="token" value="<%=session.getAttribute("token") %>"> 用戶名：<input type="text" name="username"> <input type="submit" value="提交"> </form> </body></html>package cn.itcast.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class DoFormServlet extends HttpServle