Util.java
import java.sql.*;
public class Util {
private Connection conn;
private Statement stm;
private ResultSet rs;
private String classname="com.mysql.jdbc.Driver";
private String url="jdbc:mysql://localhost:3306/test";
public Util(){
try {
Class.forName(classname);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/*获取连接*/
public Connection getConn() {
try {
conn=DriverManager.getConnection(url,"root","123456");
} catch (SQLException e) {
e.printStackTrace(System.err);
conn=null;
}
return conn;
}
/*关闭连接*/
public void closed(){
try {
if (rs!=null) {
rs.close();
}
if (stm!=null) {
stm.close();
}
if(conn!=null){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public void setConn(Connection conn) {
this.conn = conn;
}
/*执行语句*/
public Statement getStm() {
try {
conn=getConn();
stm=conn.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
return stm;
}
public Statement getStmed(){
try {
conn=getConn();
stm=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
} catch (SQLException e) {
e.printStackTrace();
}
return stm;
}
public ResultSet getAllRs(){
String sql="select * from u";
try {
stm=getStmed();
rs=stm.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
public ResultSet getPartRs(String subsql,String subsqlvalue){
if(subsql==null){
subsql="";
}
if(subsqlvalue==null){
subsqlvalue="";
}
String sql= "select * from u where "+subsql+" ='"+subsqlvalue+"'";
try {
stm=getStmed();
rs=stm.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
index.jsp
<body>
<form action="result.jsp" method="post">
<table>
<tr bgcolor="lightgrey" height="25">
<td align="center">Id</td>
<td align="center">用户名</td>
<td align="center">密码</td>
</tr>
<jsp:useBean id="db" class="com.count.Util" scope="page"></jsp:useBean>
<%
ResultSet rsall = db.getAllRs();
while(rsall.next()){
%>
<tr>
<td align="center"><%=rsall.getString("id") %></td>
<td align="center"><%=rsall.getString("name") %></td>
<td align="center"><%=rsall.getString("pwd") %></td>
</tr>
<%
}
%>
<tr bgcolor="lightgrey">
<td align="center" colspan="5">
查询类型：
<select name="subsql">
<option value="id">Id</option>
<option value="name">用户名</option>
<option value="pwd">密码</option>
</select>
<input type="text" name="subsqlvalue" size="17">
<input type="submit" name="searchpart" value="查询" onclick="return check()">
</td>
</tr>
</table>
</form>
<table>
<tr bgcolor="skyblue">
<td align="center">生成的版权信息</td>
</tr>
<tr>
<td>
<jsp:useBean id="copyright" class="com.count.Copyright"></jsp:useBean>
<jsp:getProperty property="copyrightStr" name="copyright"/>
</td>
</tr>
</table>
</body>
result.jsp
<body>
<jsp:useBean id="db" class="com.count.Util" scope="page"></jsp:useBean>
<%
ResultSet rs = null;
boolean mark=true;
String mess="";
String subsql= request.getParameter("subsql");
String subsqlvalue=request.getParameter("subsqlvalue");
%>
<table>
<tr>
<td align="center" colspan="5"><%=mess %></td>
</tr>
<tr bgcolor="lightgrey" height="20">
<td align="center">Id</td>
<td align="center">用户名</td>
<td align="center">密码</td>
</tr>
<%
rs=db.getPartRs(subsql, subsqlvalue);
if(!rs.next()){
%>
<tr>
<td align="center" colspan="5">没有记录显示！</td>
</tr>
<%
}else{
rs.previous();
while(rs.next()){
%>
<tr>
<td align="center"><%=rs.getString(1) %></td>
<td align="center"><%=rs.getString(2) %></td>
<td align="center"><%=rs.getString(3) %></td>
</tr>
<%
}
}
%>
</table>
</body>
3.PNG
4.PNG
网友评论