使用servlet和JavaBean访问MySQL

文章作者 100test 发表时间 2007:09:15 12:08:09
来源 100Test.Com百考试题网

使用Servlet和Java Bean访问MySQL

运行环境: 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:



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.*.