jdbc servlet 基础连接数据库实现 WEB项目
创建web project
导入 oracle jar包 一般在 D:\oracle\product\10.2.0\db_2\jdbc\lib 目录下 ojdbc14.jar
连接字符串：
mysql driver: org.gjt.mm.mysql.Driver
URL: jdbc:mysql://localhost:3306/test
oracle dirver: oracle.jdbc.driver.OracleDriver
URL: jdbc:oracle:thin:@localhost:1521:dbwang
创建 BaseDao
public class BaseDao {
public static final String DRIVER="org.gjt.mm.mysql.Driver";
public static final String URL="jdbc:mysql://localhost:3306/test";
public static final String USERNAME="root";
public static final String PWD="root";
// 获得连接
public Connection getConn() throws ClassNotFoundException,SQLException{
Class.forName(DRIVER);
Connection conn=DriverManager.getConnection(URL, USERNAME, PWD);
return conn;
}
// 释放资源
public void closeAll(Connection conn,Statement state,ResultSet rs){
try {
if(rs!=null){ rs.close();}
if(state!=null){ state.close();}
if(conn!=null){ conn.close();}
} catch (Exception e) {
e.printStackTrace();
}
}
// 执行CUD指令
public int executeSQL(String sql,String [] args){
int rs=0;
Connection conn=null;
PreparedStatement state=null;
try {
conn=getConn();
state=conn.prepareStatement(sql);
if(args!=null&&args.length>0){
for (int i = 0; i < args.length; i++) {
state.setString(i+1, args[i]);
}
}
rs=state.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally{closeAll(conn, state, null);
}
return rs;
}
}
再创建 StuinfoDao 继承 BaseDao
public class StuinfoDao extends BaseDao {
/**
* 增加
*/
public int addStu(Stuinfo stu){
int rs=0;
String sql="insert into stuinfo (name,age,sex,address) value (?,?,?,?)";
String [] args={stu.getName(),stu.getAge()+"",stu.getSex(),stu.getAddress()};
rs=executeSQL(sql, args);
return rs;
}
/**
* 删除
*/
public int delStu(int id){
int rs=0;
String sql="delete from stuinfo where id="+id;
String [] args={id+""};
rs=executeSQL(sql, args);
return rs;
}
/**
* 修改
*/
public int updateStu(Stuinfo stu){
int rs=0;
String sql="update stuinfo name=?,age=?,sex=?,address=? where id=?";
String [] args={stu.getName(),stu.getAge()+"",stu.getSex(),stu.getAddress(),stu.getId()+""};
rs=executeSQL(sql, args);
return rs;
}
// 9:26
/**
* 查找页数
*/
public int findStuPageCount(Stuinfo stu,int number){
int result=0;
int count=0;
Connection conn=null;
PreparedStatement state=null;
ResultSet rs=null;
String sql="select count(*) as c from stuinfo where 1=1 ";
List list=new ArrayList();
if (stu!=null&&!stu.equals("")) {
if(stu.getId()!=0){
sql+=" id=?";
list.add(stu.getId()+"");
}
if(stu.getName()!=null&&!stu.getName().equals("")){
sql+=" name like ?";
list.add("%"+stu.getName()+"%");
}
if(stu.getAge()!=0){
sql+=" age=?";
list.add(stu.getAge()+"");
}
if(stu.getSex()!=null&&!stu.getSex().equals("")){
sql+=" sex=?";
list.add(stu.getSex());
}
if(stu.getAddress()!=null&&!stu.getAddress().equals("")){
sql+=" address like ?";
list.add("%"+stu.getAddress()+"%");
}
}
Object [] args=(Object[])list.toArray();
try {
conn=getConn();
state=conn.prepareStatement(sql);
if(args!=null&&args.length>0){
for (int i = 0; i < args.length; i++) {
state.setObject(i+1, args[i]);
}
}
rs=state.executeQuery();
if(rs.next()){
count=rs.getInt("c");
}
} catch (Exception e) {
e.printStackTrace();
}finally{ closeAll(conn, state, rs);}
result=(count+number-1)/number;
return result;
}
/**
* 查询
*
*/
public List<Stuinfo> findStuinfo(Stuinfo stu,int currretPage,int number){
List<Stuinfo> stus=new ArrayList<Stuinfo>();
Connection conn=null;
PreparedStatement state=null;
ResultSet rs=null;
String sql="select * from stuinfo where 1=1 ";
List list=new ArrayList();
if (stu!=null&&!stu.equals("")) {
if(stu.getId()!=0){
sql+=" id=?";
list.add(stu.getId()+"");
}
if(stu.getName()!=null&&!stu.getName().equals("")){
sql+=" name like ?";
list.add("%"+stu.getName()+"%");
}
if(stu.getAge()!=0){
sql+=" age=?";
list.add(stu.getAge()+"");
}
if(stu.getSex()!=null&&!stu.getSex().equals("")){
sql+=" sex=?";
list.add(stu.getSex());
}
if(stu.getAddress()!=null&&!stu.getAddress().equals("")){
sql+=" address like ?";
list.add("%"+stu.getAddress()+"%");
}
}
sql+=" limit ?,?";
int num=(currretPage-1)*number;
list.add(num);
list.add(number);
Object [] args=(Object[])list.toArray();
try {
conn=getConn();
state=conn.prepareStatement(sql);
if(args!=null&&args.length>0){
for (int i = 0; i < args.length; i++) {
state.setObject(i+1, args[i]);
}
}
rs=state.executeQuery();
while(rs.next()){
int id=rs.getInt("id");
String name=rs.getString("name");
int age=rs.getInt("age");
String sex=rs.getString("sex");
String address=rs.getString("address");
Stuinfo newstu=new Stuinfo(id, name, age, sex, address);
stus.add(newstu);
}
} catch (Exception e) {
e.printStackTrace();
}finally{ closeAll(conn, state, rs);}
return stus;
}
/**
* 根据ID查询
*/
public Stuinfo findStuById(int id){
Stuinfo stu =null;
String sql="select * from stuinfo id="+id;
Connection conn=null;
Statement state=null;
ResultSet rs=null;
try {
conn=getConn();
state=conn.createStatement();
rs=state.executeQuery(sql);
if (rs.next()) {
stu=new Stuinfo(id, rs.getString("name"), rs.getInt("age"), rs.getString("sex"), rs.getString("address"));
}
} catch (Exception e) {
e.printStackTrace();
}finally{ closeAll(conn, state, rs);}
return stu;
}
}
创建 servlet DoAdd extends HttpServlet
public class DoAdd extends HttpServlet {
/**
* Constructor of the object.
*/
public DoAdd() {
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 {
response.setContentType("text/html;charset=utf-8");
doPost(request, response);
}
/**
* 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 {
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
String name=request.getParameter("name");
String strage=request.getParameter("age");
String sex=request.getParameter("sex");
String address=request.getParameter("address");
int age=0;
if (strage!=null&&!strage.equals("")) {
age=Integer.parseInt(strage);
}
new StuinfoDao().addStu(new Stuinfo(name, age, sex, address));
response.sendRedirect("doSearchStu");
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
一定要记得配置 web.xml 文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>DoAdd</servlet-name>
<servlet-class>com.tc.stuinfoservlet.DoAdd</servlet-class>
</servlet>
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>DoDel</servlet-name>
<servlet-class>com.tc.stuinfoservlet.DoDel</servlet-class>
</servlet>
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>DoUpdate</servlet-name>
<servlet-class>com.tc.stuinfoservlet.DoUpdate</servlet-class>
</servlet>
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>Dos</servlet-name>
<servlet-class>com.tc.stuinfoservlet.Dos</servlet-class>
</servlet>
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>DoSearchStu</servlet-name>
<servlet-class>com.tc.stuinfoservlet.DoSearchStu</servlet-class>
</servlet>
<servlet>
<description>显示description</description>
<display-name>显示display</display-name>
<servlet-name>DoFindStu</servlet-name>
<servlet-class>com.tc.stuinfoservlet.DoFindStu</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DoAdd</servlet-name>
<url-pattern>/doAdd</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>DoDel</servlet-name>
<url-pattern>/doDel</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>DoUpdate</servlet-name>
<url-pattern>/doUpdate</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Dos</servlet-name>
<url-pattern>/servlet/Dos</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>DoSearchStu</servlet-name>
<url-pattern>/doSearchStu</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>DoFindStu</servlet-name>
<url-pattern>/doFindStu</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>