1、Out對(duì)象
主要用來(lái)向客戶端輸出各種格式的數(shù)據(jù),并且管理應(yīng)用服務(wù)器上的輸出緩沖區(qū),Out對(duì)象的基類是javax.servlet.jsp.JspWriter類。
Out的主要方法:
out.println(DataType);或out.print(DataType);
實(shí)例:
<%@page language="java"
contentType="text/html;charset=gb2312"
import="java.util.*"
%>
<%
out.println(new Date().toLocaleString());
out.print("
");
out.print("測(cè)試成功");
%>
2、Request對(duì)象
Request.setAttribute()與Request.getAttribute()方法實(shí)例(也可以使用forward建立請(qǐng)求關(guān)系):
主頁(yè)面:
<%@page language="java" contentType="text/html;charset=gb2312" %>
<%@ include file="1.jsp" %>
你剛才輸入的內(nèi)容是:
<%=request.getAttribute("gr")%>
引入頁(yè)面:
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<% request.setAttribute("gr","123333");%>
Request.getParameter()方法實(shí)例
主頁(yè)面
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
引入頁(yè)面
<%!protected int count=0;%>
<%=++count%>
JavaBean設(shè)計(jì)規(guī)范及實(shí)例
javaBean的設(shè)計(jì)規(guī)范:
一個(gè)javaBean類必須是一個(gè)公共類
一個(gè)javaBean類必須有一個(gè)空的構(gòu)造函數(shù)
一個(gè)javaBean類不應(yīng)有公共實(shí)例變量
持有值應(yīng)該通過(guò)一組存取方法(getXxx和setXxx)來(lái)訪問(wèn)
實(shí)例:
package Show;
import java.sql.*;
public class DBconn{
private String sDBDriver="org.gjt.mm.mysql.Driver";
private String sConnStr="jdbc:mysql://10.1.1.79:3306/web?user=root&password=2676141";
private Connection conn=null;
private ResultSet rs=null;
public DBconn(){
try{
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e){
System.out.println("DBconn():"+e.getMessage());
}
}
public String getsConnStr(){
return sConnStr;
}
public void setsConnStr(String sConnStr){
this.sConnStr=sConnStr;
}
public void executeUpdate(String sql)throws Exception{
sql=new String(sql.getBytes("GBK"),"ISO8859_1");
try{
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
stmt.executeUpdate(sql);
conn.close();
stmt.close();
}
catch(SQLException ex){
System.out.println("sql.executeUpdate:"+ex.getMessage());
}
}
public ResultSet executeQuery(String sql)throws Exception{
rs=null;
try{
sql=new String(sql.getBytes("GBK"),"ISO8859_1");
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
conn.close();
stmt.close();
}
catch(SQLException ex){
System.out.println("sql.executeQuery:"+ex.getMessage());
}
return rs;
}
}