java ee开发 java ee开发环境

C:\>
C:\>cd Program Files\MySQL\bin
C:\Program Files\MySQL\bin>

C:\Program Files\MySQL\bin>mysql -u root -p
Enter password: ********
mysql>

mysql> use TEST;
mysql> create table Employees
(
id int not null,
age int not null,
first varchar (255),
last varchar (255)
);
Query OK, 0 rows affected (0.08 sec)
mysql>

mysql> INSERT INTO Employees VALUES (100, 18, 'Zara', 'Ali');
Query OK, 1 row affected (0.05 sec)
mysql> INSERT INTO Employees VALUES (101, 25, 'Mahnaz', 'Fatma');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO Employees VALUES (102, 30, 'Zaid', 'Khan');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO Employees VALUES (103, 28, 'Sumit', 'Mittal');
Query OK, 1 row affected (0.00 sec)
mysql>

// 加载必需的库
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class DatabaseAccess extends HttpServlet{
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
// JDBC 驱动器名称和数据库的 URL
static final String JDBC_DRIVER="com.mysql.jdbc.Driver";
static final String DB_URL="jdbc:mysql://localhost/TEST";
// 数据库的凭据
static final String USER = "root";
static final String PASS = "password";
// 设置响应内容类型
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String title = "数据库结果";
String docType =
""-//w3c//dtd html 4.0 " +
"transitional//en\">\n";
out.println(docType +
"\n" +
"
" + title + "\n" + 
 
"
\n" + 
 
"
" + title + "
\n"); 
 
try{
// 注册 JDBC 驱动器
Class.forName("com.mysql.jdbc.Driver");
// 打开一个连接
conn = DriverManager.getConnection(DB_URL,USER,PASS);
// 执行 SQL 查询
stmt = conn.createStatement();
String sql;
sql = "SELECT id, first, last, age FROM Employees";
ResultSet rs = stmt.executeQuery(sql);
// 从结果集中提取数据
while(rs.next()){
// 根据列名称检索
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last");
// 显示值
out.println("ID: " + id + "");
out.println(", Age: " + age + "");
out.println(", First: " + first + "");
out.println(", Last: " + last + "");
}
out.println("");
// 清理环境
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
// 处理 JDBC 错误
se.printStackTrace();
}catch(Exception e){
// 处理 Class.forName 错误
e.printStackTrace();
}finally{
// 后是用于关闭资源的块
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}// 我们不能做什么
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
} //end try
}
}
让我们来编译上面的 Servlet，并在 web.xml 文件中修改以下内容：
....
DatabaseAccess
DatabaseAccess
DatabaseAccess
/DatabaseAccess
....