完整的CRUD——javaweb
1，总体架构
index是进去的页面，
可以跳转Insert的增加页面，operatePerson是根据传进来的URI来判断增删改查的页面，
DbManager.java是封装的数据库操作类, Pagination.java是页脚的信息栏
2，index页面
final int pageSize = 5;//一页显示多少纪录
int pageNum = 1;//当前页数
int pageCount = 1;//总页数
int recordCount = 0;//总记录数
<form action="operatePerson.jsp" method="post">
<table border="1">
<%
for(; resultSet.next();){
out.println("<tr>");
String name = resultSet.getString("name");
out.println("<td>" + name + "</td>");
out.println("<td>" + resultSet.getString("age") + "</td>");
out.println("<td>" + resultSet.getString("sex") + "</td>");
out.println("<td><a href='operatePerson.jsp?action=delete&name=" + name +"'>删除</a></td>");
out.println("<td><a href='operatePerson.jsp?action=edit&name=" + name +"'>修改</a></td>");
out.println("</tr>");
}
%>
</table>
<%=Pagination.getPagination(pageNum, pageCount
, recordCount, request.getRequestURI()) %>
画出表，包括页脚，（上面的form其实没有什么用
分页技术使用数据库的 select * from person limit ?,? ----意思是从哪条开始（不包括这一条）的 n条记录
问号使用preparedStatement语句来实现
代码：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="java.sql.DriverManager"%>
<%@ page import="java.sql.Connection"%>
<%@ page import="java.sql.Statement"%>
<%@ page import="java.sql.ResultSet"%>
<%@ page import="java.sql.PreparedStatement"%>
<%@ page import="java.sql.SQLException"%>
<%@ page import="testPackage.DbManager" %>
<%@ page import="testPackage.Pagination" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head> <%
final int pageSize = 5;//一页显示多少纪录
int pageNum = 1;//当前页数
int pageCount = 1;//总页数
int recordCount = 0;
try{//当前页数
pageNum = Integer.parseInt(request.getParameter("pageNum"));
System.out.println("0000:" + pageNum);
}catch(Exception e){}
String sql = null;
Connection con = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try{
sql = "select count(*) from person";
recordCount = DbManager.getCount(sql);
pageCount = (recordCount + pageSize - 1) / pageSize;
int startRecord = (pageNum - 1) * pageSize;
sql = "select * from person limit ?,?";
con = DbManager.getConnection();
preparedStatement = con.prepareStatement(sql);
DbManager.setParams(preparedStatement, startRecord, pageSize);
resultSet = preparedStatement.executeQuery();
%>
<body>
<a href="Insert.jsp">新建一个</a>
<form action="operatePerson.jsp" method="post">
<table border="1">
<%
for(; resultSet.next();){
out.println("<tr>");
String name = resultSet.getString("name");
out.println("<td>" + name + "</td>");
out.println("<td>" + resultSet.getString("age") + "</td>");
out.println("<td>" + resultSet.getString("sex") + "</td>");
out.println("<td><a href='operatePerson.jsp?action=delete&name=" + name +"'>删除</a></td>");
out.println("<td><a href='operatePerson.jsp?action=edit&name=" + name +"'>修改</a></td>");
out.println("</tr>");
}
%>
</table>
<%=Pagination.getPagination(pageNum, pageCount
, recordCount, request.getRequestURI()) %>
<br/>
<%=pageNum %>
</form>
<%
}catch(SQLException e1){
out.println("0001" + e1.getMessage());
}
finally {
if (resultSet != null)
resultSet.close();
if (preparedStatement != null)
preparedStatement.close();
if (con != null)
con.close();
}
%>
</body>
</html>
2，operatePerson.jsp页面
我写的时候没有使用DbManager类，在里面的增删改都用了原始的操作
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");//一定要
String action = request.getParameter("action");//先接受是什么操作
增：request.getPararmeter("name...")通过这个方法来获得表传进来的数据
删：request.getPararmeter("name")通过这个方法来获得uri传进来的paramer
改：request.getPararmeter("name")通过这个方法来获得uri传进来的paramer，（我设计的时候没有完善好，默认他们不能有同名，所以不能改名字
request.setAttribute("name", resultSet.getString("name")//把传进来的参数穿进去request里面，用forward转向到insert的页面在，那样insert可以从request里面提取数据（同时也把"save"信息传过去)，和真正的插入有了区别
在insert会判断是save的传递，把数据传回来operate页面，做真正的修改
3，insert页面
会根据传过来的action判断是插入还是修改，以此来修改uri，form表给的提交方式要改为post ,因为这样表格的内容就不能形象uri的传递，
value="${name}"的时候，在修改的时候会显示值，注意：el表达式，${name}或者${requestScope.name}而不是${request.name}
4,Pagination.java
页脚，用StringBuffer类，append字符串
5，DbManager.java
数据库管理类
public static Connection getConnection(String dbName, String userName,String password)
public static Connection getConnection() //获得con对象
public static void setParams(PreparedStatement preparedStatement,Object... params) //把preparedStatement放进去，发若干个参数，preparedStatement.setInt.....之类的
public static int executeUpdate(String sql)
public static int executeUpdate(String sql, Object... params) //对上面方法的封装，穿进去sql的字符串就行了
源码：
DbManager
package testPackage; import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types; public class DbManager {
public static Connection getConnection() throws SQLException,
ClassNotFoundException {
return getConnection("test", "kooing", "");
} public static Connection getConnection(String dbName, String userName,
String password) throws SQLException, ClassNotFoundException {
String url = "jdbc:mysql://localhost:3306/" + dbName;
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(url);
return con;
} public static void setParams(PreparedStatement preparedStatement,
Object... params) throws SQLException {
for (int i = 1; i <= params.length; i++) {
Object param = params[i - 1];
if (param == null) {
preparedStatement.setNull(i, Types.NULL);
} else if (param instanceof Integer) {
preparedStatement.setInt(i, (Integer) param);
} else if (param instanceof String) {
preparedStatement.setString(i, (String) param);
}
}
} public static int executeUpdate(String sql) throws SQLException,
ClassNotFoundException {
return executeUpdate(sql, new Object[] {});
} public static int executeUpdate(String sql, Object... params)
throws SQLException, ClassNotFoundException {
Connection con = null;
PreparedStatement preparedStatement = null;
try {
con = getConnection();
preparedStatement = con.prepareStatement(sql);
setParams(preparedStatement, params);
return preparedStatement.executeUpdate();
} finally {
if (preparedStatement != null)
preparedStatement.close();
if (con != null)
con.close();
}
} public static int getCount(String sql) throws SQLException,
ClassNotFoundException {
Connection con = null;
Statement statement = null;
ResultSet rs = null;
try {
con = getConnection();
statement = con.createStatement();
rs = statement.executeQuery(sql);
rs.next();
return rs.getInt(1);
} finally {
if (rs != null)
rs.close();
if (statement != null)
statement.close();
if (con != null)
con.close();
}
}
}
Pagination
package testPackage;
public class Pagination {
public static String getPagination(int pageNum, int pageCount,
int recordCount, String pageUrl) {
String url = pageUrl.contains("?") ? pageUrl : pageUrl + "?";
if (!url.endsWith("?") && !url.endsWith("&")) {
url += "&";
}
StringBuffer buffer = new StringBuffer();
buffer.append("第 " + pageNum + "/" + pageCount + "页，共" + recordCount
+ "纪录。");
buffer.append(pageNum == 1 ? "第一页" : "<a href='" + url
+ "pageNum=1'>第一页</a>");
// buffer.append(pageNum == 1 ? "第一页" : "<a href='" + url + "pageNum=" +
// 1
// + "'>第一页</a>");
buffer.append(pageNum == 1 ? "上一页" : "<a href='" + url + "pageNum="
+ (pageNum - 1) + "'>上一页</a>");
buffer.append(pageNum == pageCount ? "下一页" : "<a href='" + url
+ "pageNum=" + (pageNum + 1) + "'>下一页</a>");
buffer.append(pageNum == pageCount ? "最后一页" : "<a href='" + url
+ "pageNum=" + pageCount + "'>最后一页</a>");
return buffer.toString();
}
}
index
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="java.sql.DriverManager"%>
<%@ page import="java.sql.Connection"%>
<%@ page import="java.sql.Statement"%>
<%@ page import="java.sql.ResultSet"%>
<%@ page import="java.sql.PreparedStatement"%>
<%@ page import="java.sql.SQLException"%>
<%@ page import="testPackage.DbManager" %>
<%@ page import="testPackage.Pagination" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head> <%
final int pageSize = 5;//一页显示多少纪录
int pageNum = 1;//当前页数
int pageCount = 1;//总页数
int recordCount = 0;
try{//当前页数
pageNum = Integer.parseInt(request.getParameter("pageNum"));
System.out.println("0000:" + pageNum);
}catch(Exception e){}
String sql = null;
Connection con = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try{
sql = "select count(*) from person";
recordCount = DbManager.getCount(sql);
pageCount = (recordCount + pageSize - 1) / pageSize;
int startRecord = (pageNum - 1) * pageSize;
sql = "select * from person limit ?,?";
con = DbManager.getConnection();
preparedStatement = con.prepareStatement(sql);
DbManager.setParams(preparedStatement, startRecord, pageSize);
resultSet = preparedStatement.executeQuery();
%>
<body>
<a href="Insert.jsp">新建一个</a>
<form action="operatePerson.jsp" method="post">
<table border="1">
<%
for(; resultSet.next();){
out.println("<tr>");
String name = resultSet.getString("name");
out.println("<td>" + name + "</td>");
out.println("<td>" + resultSet.getString("age") + "</td>");
out.println("<td>" + resultSet.getString("sex") + "</td>");
out.println("<td><a href='operatePerson.jsp?action=delete&name=" + name +"'>删除</a></td>");
out.println("<td><a href='operatePerson.jsp?action=edit&name=" + name +"'>修改</a></td>");
out.println("</tr>");
}
%>
</table>
<%=Pagination.getPagination(pageNum, pageCount
, recordCount, request.getRequestURI()) %>
<br/>
<%=pageNum %>
</form>
<%
}catch(SQLException e1){
out.println("0001" + e1.getMessage());
}
finally {
if (resultSet != null)
resultSet.close();
if (preparedStatement != null)
preparedStatement.close();
if (con != null)
con.close();
}
%>
</body>
</html>
operate
<%@page import="java.sql.DriverManager"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="java.sql.DriverManager"%>
<%@ page import="java.sql.Connection"%>
<%@ page import="java.sql.Statement"%>
<%@ page import="java.sql.ResultSet"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<%
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
String action = request.getParameter("action");
String sql = null;
if ("add".equals(action)) {
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String sex = request.getParameter("sex");
sql = "insert into person values('" + name + "','" + age
+ "','" + sex + "')";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "kooing", "");
Statement sm = con.createStatement();
int resultSet = sm.executeUpdate(sql);
out.println(sql);
} catch (Exception e) { }
}
if ("delete".equals(action)) {
String name = request.getParameter("name");
System.out.println(name);
sql = "delete from person where name = '" + name + "'";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "kooing", "");
Statement sm = con.createStatement();
int resultSet = sm.executeUpdate(sql);
out.println(sql);
} catch (Exception e) { }
}
if ("edit".equals(action)) {
try {
String name = request.getParameter("name");
sql = "select * from person where name ='" + name + "'";
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "kooing", "");
Statement sm = con.createStatement();
ResultSet resultSet = sm.executeQuery(sql);
out.println(sql);
resultSet.next();
request.setAttribute("name", resultSet.getString("name"));
request.setAttribute("age", resultSet.getString("age"));
request.setAttribute("sex", resultSet.getString("sex"));
request.setAttribute("action", action);
request.getRequestDispatcher("Insert.jsp").forward(request,
response);
} catch (Exception e) {
}
}
if("save".equals(action)){
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String sex = request.getParameter("sex");
sql = "update person set "
+ "name='" + name
+ "',age='" + age
+ "',sex='" + sex + "' where name ='" + name +"'";
System.out.println(sql);
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test",
"kooing", "");
Statement sm = con.createStatement();
int result = sm.executeUpdate(sql);
}
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>My JSP 'operatePerson.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
--> </head> <body>
This is my JSP page.
<br>
<a href="index.jsp">主页</a>
</body>
</html>
insert
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>My JSP 'Insert.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
--> </head> <body>
<%
String myAction = (String)request.getAttribute("action");
myAction = myAction == null? "add" : "save";
System.out.println(myAction);
System.out.println(request.getAttribute("name"));
System.out.println(request.getAttribute("age"));
System.out.println(request.getAttribute("sex"));
%>
<form action="operatePerson.jsp?action=<%=myAction %>" method="post">
姓名<input type="text" name="name" value="${name }"><br/>
年龄<input type="text" name="age" value="${age }"><br/>
性别<input type="text" name="sex" value="${sex }"><br/>
<input type="submit">
</form>
</body>
</html>
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