package com.product.dbutil.register.action;控制层
package com.product.dbutil.register.service;服务层
package com.product.dbutil.register.dao;数据访问层。
控制层的定义代码：
package com.product.dbutil.register.action;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.product.dbutil.register.dao.RegisterDao;
import com.product.dbutil.register.service.RegisterService;
import com.sun.org.apache.bcel.internal.generic.ARRAYLENGTH;
public class RegisterAction extends HttpServlet {
private RegisterService service;//服务层接口
/**
* Constructor of the object.
*/
public RegisterAction() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request
* the request send by the client to the server
* @param response
* the response send by the server to the client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);//复写doPost方法
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to
* post.
*
* @param request
* the request send by the client to the server
* @param response
* the response send by the server to the client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String path = request.getContextPath();//用来重定向
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
String username = request.getParameter("username");
String pswd = request.getParameter("pswd");
String realname = request.getParameter("realname");
List<Object> params = new ArrayList<Object>();
params.add(username);
params.add(pswd);
params.add(realname);
boolean flag = service.registerUser(params);
if (flag) {
response.sendRedirect(path + "/index.jsp");//重定向的实现
}
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException
* if an error occurs
*/
public void init() throws ServletException {
// Put your code here
service = new RegisterDao();
}
}
服务层，定义业务逻辑处理规范。代码如下：
package com.product.dbutil.register.service;
import java.util.List;
public interface RegisterService {
//完成用户的注册功能
public boolean registerUser(List<Object> params);
}
package com.product.dbutil.register.dao;
import java.util.List;
import com.product.dbutil.jdbc.JdbcUtils;
import com.product.dbutil.register.service.RegisterService;
public class RegisterDao implements RegisterService {
private JdbcUtils utils = null;
public RegisterDao() {
//操作数据库
utils = new JdbcUtils();
}
/*
* 完成了对用户注册的dao的编写
*
* @see
* com.product.dbutil.register.service.RegisterService#registerUser(java
* .util.List)
*/
public boolean registerUser(List<Object> params) {
// TODO Auto-generated method stub
boolean flag = false;
String sql = "insert into userinfo(username,pswd,realname) values(?,?,?)";
try {
// 先获得链接
utils.getConnection();
flag = utils.updateByPreparedStatement(sql, params);
System.out.println("-flag-->>" + flag);
} catch (Exception e) {
e.printStackTrace();
// TODO: handle exception
} finally {
// 关闭数据库的链接
utils.releaseConn();
}
return flag;
}
}
数据库工具类：
package com.product.dbutil.jdbc;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class JdbcUtils {
// 表示定义数据库的用户名
private final String USERNAME = "root";
// 定义数据库的密码
private final String PASSWORD = "admin";
// 定义数据库的驱动信息
private final String DRIVER = "com.mysql.jdbc.Driver";
// 定义访问数据库的地址
private final String URL = "jdbc:mysql://localhost:3306/mydb";
// 定义数据库的链接
private Connection connection;
// 定义sql语句的执行对象
private PreparedStatement pstmt;
// 定义查询返回的结果集合
private ResultSet resultSet;
// 实现批处理操作的功能
private Statement stmt;
public JdbcUtils() {
try {
Class.forName(DRIVER);
System.out.println("注册驱动成功!!");
} catch (Exception e) {
// TODO: handle exception
}
}
// 定义获得数据库的链接
public Connection getConnection() {
try {
connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
} catch (Exception e) {
// TODO: handle exception
}
return connection;
}
public boolean deleteByBatch(String[] sql) throws SQLException{
boolean flag = false;
stmt = connection.createStatement();
if(sql!=null){
for(int i=0;i<sql.length;i++){
stmt.addBatch(sql[i]);
}
}
int[] count = stmt.executeBatch();
if(count!=null){
flag = true;
}
return flag;
}
/**
* 完成对数据库的表的添加删除和修改的操作
*
* @param sql
* @param params
* @return
* @throws SQLException
*/
public boolean updateByPreparedStatement(String sql, List<Object> params)
throws SQLException {
boolean flag = false;
int result = -1;// 表示当用户执行添加删除和修改的时候所影响数据库的行数
pstmt = connection.prepareStatement(sql);
int index = 1;
if (params != null && !params.isEmpty()) {
for (int i = 0; i < params.size(); i++) {
pstmt.setObject(index++, params.get(i));
}
}
result = pstmt.executeUpdate();
flag = result > 0 ? true : false;
return flag;
}
/**
* 查询返回单条记录
*
* @param sql
* @param params
* @return
* @throws SQLException
*/
public Map<String, Object> findSimpleResult(String sql, List<Object> params)
throws SQLException {
Map<String, Object> map = new HashMap<String, Object>();
int index = 1;
pstmt = connection.prepareStatement(sql);
if (params != null && !params.isEmpty()) {
for (int i = 0; i < params.size(); i++) {
pstmt.setObject(index++, params.get(i));
}
}
resultSet = pstmt.executeQuery();// 返回查询结果
ResultSetMetaData metaData = resultSet.getMetaData();
int col_len = metaData.getColumnCount();// 获得列的名称
while (resultSet.next()) {
for (int i = 0; i < col_len; i++) {
String cols_name = metaData.getColumnName(i + 1);
Object cols_value = resultSet.getObject(cols_name);
if (cols_value == null) {
cols_value = "";
}
map.put(cols_name, cols_value);
}
}
return map;
}
/**
* 查询返回多行记录
*
* @param sql
* @param params
* @return
* @throws SQLException
*/
public List<Map<String, Object>> findMoreResult(String sql,
List<Object> params) throws SQLException {
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
int index = 1;
pstmt = connection.prepareStatement(sql);
if (params != null && !params.isEmpty()) {
for (int i = 0; i < params.size(); i++) {
pstmt.setObject(index++, params.get(i));
}
}
resultSet = pstmt.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while (resultSet.next()) {
Map<String, Object> map = new HashMap<String, Object>();
for (int i = 0; i < cols_len; i++) {
String cols_name = metaData.getColumnName(i + 1);
Object cols_value = resultSet.getObject(cols_name);
if (cols_value == null) {
cols_value = "";
}
map.put(cols_name, cols_value);
}
list.add(map);
}
return list;
}
// jdbc的封装可以用反射机制来封装：
public <T> T findSimpleRefResult(String sql, List<Object> params,
Class<T> cls) throws Exception {
T resultObject = null;
int index = 1;
pstmt = connection.prepareStatement(sql);
if (params != null && !params.isEmpty()) {
for (int i = 0; i < params.size(); i++) {
pstmt.setObject(index++, params.get(i));
}
}
resultSet = pstmt.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while (resultSet.next()) {
// 通过反射机制创建实例
resultObject = cls.newInstance();
for (int i = 0; i < cols_len; i++) {
String cols_name = metaData.getColumnName(i + 1);
Object cols_value = resultSet.getObject(cols_name);
if (cols_value == null) {
cols_value = "";
}
Field field = cls.getDeclaredField(cols_name);
field.setAccessible(true);// 打开javabean的访问private权限
field.set(resultObject, cols_value);
}
}
return resultObject;
}
/**
* 通过反射机制访问数据库
*
* @param <T>
* @param sql
* @param params
* @param cls
* @return
* @throws Exception
*/
public <T> List<T> findMoreRefResult(String sql, List<Object> params,
Class<T> cls) throws Exception {
List<T> list = new ArrayList<T>();
int index = 1;
pstmt = connection.prepareStatement(sql);
if (params != null && !params.isEmpty()) {
for (int i = 0; i < params.size(); i++) {
pstmt.setObject(index++, params.get(i));
}
}
resultSet = pstmt.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while (resultSet.next()) {
T resultObject = cls.newInstance();
for (int i = 0; i < cols_len; i++) {
String cols_name = metaData.getColumnName(i + 1);
Object cols_value = resultSet.getObject(cols_name);
if (cols_value == null) {
cols_value = "";
}
Field field = cls.getDeclaredField(cols_name);
field.setAccessible(true);
field.set(resultObject, cols_value);
}
list.add(resultObject);
}
return list;
}
public void releaseConn() {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (pstmt != null) {
try {
pstmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
原文：http://blog.csdn.net/u014600432/article/details/41414981