Java-KGLI工具类总结

C3p0 连接池 DB工具类：JDBCUtils :package cn.kgli.utils;import java.io.InputStream;import ng.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.sql.Statement;import java.util.ArrayList;import java.util.List;import java.util.Properties;import boPooledDataSource;public class JdbcUtils {private static ComboPooledDataSource ds = null;static{try{/*ds = new ComboPooledDataSource();ds.setDriverClass("com.mysql.jdbc.Driver");ds.setJdbcUrl("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 getConnection() throws SQLException{return ds.getConnection();}public static void release(Connection conn,Statement st,ResultSet rs){if(rs!=null){try{rs.close();}catch (Exception e) {e.printStackTrace();}rs = null;}if(st!=null){try{st.close();}catch (Exception e) {e.printStackTrace();}}if(conn!=null){try{conn.close();}catch (Exception e) {e.printStackTrace();}}}//替换dao中的增删改方法public static void update(String sql,Object params[]) throws SQLException{ Connection conn = null;PreparedStatement st = null;ResultSet rs = null;try{conn = getConnection();st = conn.prepareStatement(sql);for(int i=0;i<params.length;i++){st.setObject(i+1, params[i]);}st.executeUpdate();}finally{release(conn, st, rs);}}//替换所有dao中的查询策略模式public static Object query(String sql,Object params[],ResultSetHandler rsh) throws SQLException{Connection conn = null;PreparedStatement st = null;ResultSet rs = null;try{conn = getConnection();st = conn.prepareStatement(sql);for(int i=0;i<params.length;i++){st.setObject(i+1, params[i]);}rs = st.executeQuery();return rsh.handler(rs);}finally{release(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.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;static{try{InputStream in =JdbcUtils_DBCP.class.getClassLoader().getResourceAsStream("dbcpconfig.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 SQLException{return ds.getConnection();}public static void release(Connection conn,Statement st,ResultSet rs){if(rs!=null){try{rs.close();}catch (Exception e) {e.printStackTrace();}rs = null;}if(st!=null){try{st.close();}catch (Exception e) {e.printStackTrace();}}if(conn!=null){try{conn.close();}catch (Exception e) {e.printStackTrace();}}}}//BeanHandler.javapackage cn.kgli.utils;import ng.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 rs) {try{if(!rs.next()){return null;}Object bean = clazz.newInstance();ResultSetMetaData metadata = rs.getMetaData();int columnCount = metadata.getColumnCount(); //得到结果集中有几列数据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);Field f = clazz.getDeclaredField(coulmnName);//反射出类上列名对应的属性f.setAccessible(true);f.set(bean, coulmnData);}return bean;}catch (Exception e) {throw new RuntimeException(e);}}}BeanListHandler.javapackage cn.kgli.utils;import ng.reflect.Field;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import 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) {try{List list = new ArrayList();while(rs.next()){Object bean = clazz.newInstance();ResultSetMetaData 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()>0?list:null;}catch (Exception e) {throw new RuntimeException(e);}}}防止表单重复提交：拦截注册页面加上session tokenpackage cn.kgli.servlet;import java.io.IOException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException; import java.util.Random;import javax.servlet.ServletException;import 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, IOException {String token = TokenProccessor.getInstance().makeToken();request.getSession().setAttribute("token", token); //在服务器端保存随机数request.getRequestDispatcher("/form.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}class TokenProccessor{/**单态设计模式（保证类的对象在内存中只有一个）*1、把类的构造函数私有*2、自己创建一个类的对象*3、对外提供一个公共的方法，返回类的对象**/private TokenProccessor(){}private static final TokenProccessor instance = new TokenProccessor();public static TokenProccessor getInstance(){return instance;}public String makeToken(){ //checkException// 7346734837483 834u938493493849384 43434384String token = (System.currentTimeMillis() + newRandom().nextInt(999999999)) + "";//数据指纹 128位长 16个字节 md5try {MessageDigest md = MessageDigest.getInstance("md5");byte md5[] = md.digest(token.getBytes());//base64编码--任意二进制编码明文字符 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 HTML 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" name="token"value="<%=session.getAttribute("token") %>">用户名：<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 HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {boolean b = isToken(request); //判断用户是否是重复提交if(b==true){System.out.println("请不要重复提交");return;}request.getSession().removeAttribute("token");System.out.println("处理用户提交请求！！");}private boolean isToken(HttpServletRequest request) {String client_token = request.getParameter("token");if(client_token==null){return true;}String server_token = (String)request.getSession().getAttribute("token");if(server_token==null){return true;}if(!client_token.equals(server_token)){return true;}return false;}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}。