Jsp开发入门

安装Jdk，安装apache-tomcat
假设tomcat安装路径C:\apache-tomcat-6.0.18\，tomcat配置端口80
创建文件夹C:\apache-tomcat-6.0.18\webapps\jsptest，进入jsptest，
创建文件WEB-INF\web.xml，
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
</web-app>
在jsptest创建文件HelloWorld.jsp
<%@ page contentType="text/html;charset=gb2312"%>
<HTML>
<HEAD>
   <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=gb2312">
   <TITLE>Hello World!</TITLE>
</HEAD>
<BODY>
   <% out.println("Hello World"); %> !
</BODY>
</HTML>
通过C:\apache-tomcat-6.0.18\bin\startup.bat启动tomcat，在浏览器中输入网址http://localhost/jsptest/HelloWorld.jsp即可。

Jsp取得主机名
<% out.println(request.getHeader("Host")); %>
页面输出localhost

Jsp取得网址中传过来的参数
比如输入网址http://localhost/jsptest/HelloWorld.jsp?username=123456
<% out.println(request. getParameter ("username ")); %>
页面输出123456

使用java类
比如使用org.jivesoftware.util.Blowfish进行解密，首先将文件Blowfish.class复制到WEB_INF\classes下，注意完整路径名应该为WEB-INF\classes\org\jivesoftware\util\Blowfish.class。

在<%@ page contentType="text/html;charset=gb2312"%>之后添加代码
<%@ page import="java.util.*" %>
<%@ page import="java.io.*" %>
<%@ page import="java.net.*" %>
<%@ page import="org.jivesoftware.util.Blowfish" %>

<%
Blowfish bf = new Blowfish("0V10u835HX4x0oiK88");
bf.decryptString(password);
%>

Jsp中重定向
比如<jsp:forward page="http://www.baidu.com"/>，将页面重定向至www.baidu.com。

模拟网页登录
String surl = "http://locahost/jsptest/HelloWorld!";
URL url = new URL(surl);
//建立连接，将读到的信息输出到当前网页
URLConnection connection = url.openConnection();
String sCurrentLine = "";
String sTotalString = "";
BufferedReader l_reader = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8"));
while ((sCurrentLine = l_reader.readLine()) != null)
sTotalString += sCurrentLine + "\r\n";
out.println(sTotalString);
//使用javascript提交
out.println("<script type=\"text/javascript\">\r\n");
out.println("document.getElementsByName(\"name\")[0].value=\""+ params[1] +"\";\r\n");
out.println("document.getElementsByName(\"pass\")[0].value=\""+ params[2] +"\";\r\n");
out.println("document.forms[0].submit();\r\n");
out.println("</script>\r\n");

连接MySQL数据库
首先将mysql-connector-java-5.1.6-bin.jar复制到WEB-INF\lib\下
<%
Class.forName("com.mysql.jdbc.Driver").newInstance();
String url ="jdbc:mysql://localhost/jbpm?user=root&password=yourpass&characterEncoding=utf8";
Connection conn= DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
String sql = "select charset('abcd')";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()){
out.write(rs.getString(1));
}
out.print("数据库操作完成");
rs.close();
stmt.close();
conn.close();
%>

连接Oracle数据库
首先将ojdbc14.jar复制到WEB-INF\lib\下
<%
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
String url ="jdbc:oracle:thin:@192.168.0.1:1521:dbname";
Connection conn= DriverManager.getConnection(url,"username","password");
Statement stmt = conn.createStatement();
String sql = "select 1 from dual";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()){
out.write(rs.getString(1));
}
out.print("数据库操作完成");
rs.close();
stmt.close();
conn.close();
%>