HttpServletRequest:（客戶端的請求對象，所有客戶端傳遞給服務器端的信息都封裝在這個對象中）
1.getXXX()，可以獲取很多客戶端信息
2.getParameter(String name)，用於獲取客戶端參數信息，name用於標識客戶端參數的名字。登陸頁面的html表格
3.setCharacterEncoding(encoding)，設置請求信息的字符編碼集
HttpServletResponse:（服務器端給客戶端的響應，通常用於輸出到客戶端一些html信息）:
1.setCharacterEncoding(encoding) ，設置響應輸出流的字符編碼集
<html>
<head>
<title>logon.html</title>
</head>
<body>
<form action=../servlet/LogonServlet method=get>
<table border=1>
<tr><td>用戶名:</td>
<td><input type=text name=user></td>
</tr>
<tr><td>密碼：</td>
<td><input type=password name=pass></td>
</tr>
<tr><td colspan=2 align=center>
<input type=submit value="登陸"></td>
</tr>
<a href=../servlet/LogonServlet?user=abcccc&pass=dddd>get登陸</a>
</table>
</form>
</body>
</html>
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LogonServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("get");
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("gbk");
response.setContentType("text/html");
String user= request.getParameter("user");
String password = request.getParameter("pass");
PrintWriter out = response.getWriter();
out.println("<HTML>");
out.println(" <HEAD><TITLE>登陸</TITLE></HEAD>");
out.println(" <BODY>");
out.println(" <p>user :" + user);
out.println(" <p>password: " + password);
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
public class Employee extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("gbk");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC /"-//W3C//DTD HTML 4.01 Transitional//EN/">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
Connection con=null;
Statement st=null;
ResultSet rs=null;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
String url="jdbc:oracle:thin:@192.168.0.199:1521:udare";
con=DriverManager.getConnection(url,"udare09003","udare09003");
st=con.createStatement();
String sql="select ename,job,sal from emp";
rs=st.executeQuery(sql);
out.println("<table border=1>");
out.println("<tr><td>員工姓名</td><td>工作</td><td>工資</td></tr>");
while(rs.next()){
out.println("<tr>");
out.println("<td>"+rs.getString("ename")+"</td>");
out.println("<td>"+rs.getString("job")+"</td>");
out.println("<td>"+rs.getString("sal")+"</td>");
}
}catch(Exception e){
e.printStackTrace();
}finally{
out.flush();
out.close();
try{
rs.close();
}catch(Exception e){}
try{
st.close();
}catch(Exception e){}
try{
con.close();
}catch(Exception e){}
}
System.out.println("ok");
out.println(" </BODY>");
out.println("</HTML>");
}
}
