使用servlet和Java Bean访问MySQL
类别: JAVA教程 
行环境: JDK 5.0 + Tomcat 5.5.4
JDK安装路径: D:/Java/jdk1.5.0_01
Tomcat安装路径:D:/Tomcat 5.5
设置环境变量(控制面板->系统->高级):
java_home=D:/Java/jdk1.5.0_01
path=%JAVA_HOME%/bin
classpath=.;D:/Java/jdk1.5.0_01/lib/dt.jar;D:/Java/jdk1.5.0_01/lib/tools.jar;D:/Tomcat 5.5/common/lib/servlet-api.jar;D:/Tomcat 5.5/common/lib/mysql-connector-java-3.1.6-bin.jar;
其中D:/Tomcat 5.5/common/lib/servlet-api.jar为Tomcat的servlet API实现,一定要加上,不如无法编译servlet
D:/Tomcat 5.5/common/lib/mysql-connector-java-3.1.6-bin.jar;是MySQL的JDBC驱动,connect/J 3.1.6,可到MySQL官方网站下载
Tomcat5.5虚拟目录设定:
D:/Tomcat 5.5/conf/Catalina/localhost下新加一test.xml
内容如下:
<Context path=\"/test\" docBase=\"d:/www\" reloadable=\"true\" crossContext=\"true\" debug=\"0\" >
</Context>
d:/www路径将是我们测试网站的根目录,通过http://localhost:8080/test访问该虚拟目录
d:/www下建有目录WEB-INF,下有web.xml设置文件(可参考D:/Tomcat 5.5/webapps/ROOT/WEB-INF/web.xml),classes目录和lib目录
//连接数据库的Java Bean文件名dbconn.java
package NinGoo;
import java.sql.*;
public class dbconn {
public dbconn() {
}
//declare variable
private Connection conn = null;
ResultSet rs = null;
private String server = \"127.0.0.1\";
private String port = \"3306\";
private String db = \"test\";
private String user = \"root\";
private String pass = \"password\";
private String drivername=\"com.mysql.jdbc.Driver\";
private String URL=\"jdbc:mysql://\"+server+\":\"+port+\"/\"+db+\"?user=\"+user+\"&password=\"+pass;
public Connection getConn(){//get database connection
try{
Class.forName(drivername).newInstance();
conn = DriverManager.getConnection(URL);
}
catch(Exception e){
e.printStackTrace();
}
return this.conn ;
}
public ResultSet executeSQL(String str) {
try{
Statement stmt = conn.createStatement();
rs = stmt.executeQuery(str);
}
catch(Exception e){
e.printStackTrace();
}
return this.rs;
}
}
编译javac welcome.java,将编译后的文件welcome.class放到目录D:/www/WEB-INF/classes/NinGoo/下
//调用Java Bean的servlet welcome.java
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class welcome extends HttpServlet {
public welcome() {
}
public void doGet(HttpServletRequest Req,HttpServletResponse Res) throws ServletException,IOException {
Res.setContentType(\"text/html\");
Connection conn=null;
Statement stmt=null;
ResultSet rs = null;
try{
NinGoo.database.dbconn myconn =new NinGoo.database.dbconn();
conn = myconn.getConn() ;
rs = myconn.executeSQL(\"select * from test\"); //test是MySQL中的一个table
PrintWriter out=Res.getWriter();
out.println(\"<html><head><title>test</title></head>\");
out.println(\"<body>\");
while(rs.next()) {
out.println(rs.getString(1));
}
out.println(\"successfule!</body></html>\");
}
catch(Exception e){
}
}
}
编译javac welcome.java,将编译后的文件welcome.class放到目录D:/www/WEB-INF/classes下
然后修改D:/www/WEB-INF/web.xml,加入如下设置
<servlet>
<servlet-name>welcome</servlet-name>
<servlet-class>welcome</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>welcome</servlet-name>
<url-pattern>/welcome</url-pattern>
</servlet-mapping>
保存后重启Tomcat,然后在浏览器中敲入http://localhost:8080/test/welcome
作者Blog：http://blog.csdn.net/NinGoo/
相关文章
使用servlet和Java Bean访问MySQL
JSP+Java Bean访问MySQL数据库
编写第一个servlet
HOW TO：在 SQL Server 实例之间传输登录和密码
jsp连接数据库---Mysql
