jsp項目優秀源碼

1. jsp+servlet實現文件上傳與下載源碼

上傳：
需要導入兩個包：commons-fileupload-1.2.1.jar,commons-io-1.4.jar
import java.io.File;
import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
* 上傳附件
* @author new
*
*/
public class UploadAnnexServlet extends HttpServlet {

private static String path = "";

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

doPost(request, response);
}

/*
* post處理
* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

path = this.getServletContext().getRealPath("/upload");

try {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload up = new ServletFileUpload(factory);
List<FileItem> ls = up.parseRequest(request);

for (FileItem fileItem : ls) {
if (fileItem.isFormField()) {
String FieldName = fileItem.getFieldName();
//getName()返回的是文件名字 普通域沒有文件 返回NULL
// String Name = fileItem.getName();
String Content = fileItem.getString("gbk");
request.setAttribute(FieldName, Content);
} else {

String nm = fileItem.getName().substring(
fileItem.getName().lastIndexOf("\\") + 1);
File mkr = new File(path, nm);
if (mkr.createNewFile()) {
fileItem.write(mkr);//非常方便的方法
}
request.setAttribute("result", "上傳文件成功！");
}
}
} catch (Exception e) {
e.printStackTrace();
request.setAttribute("result", "上傳失敗，請查找原因，重新再試！");
}
request.getRequestDispatcher("/pages/admin/annex-manager.jsp").forward(
request, response);
}

}

下載（i/o流）無需導包：
import java.io.IOException;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* 下載文件
* @author
*
*/
public class DownloadFilesServlet extends HttpServlet {

/**
*
*/
private static final long serialVersionUID = 8594448765428224944L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

doPost(request, response);
}

/*
* 處理請求
* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

String name = request.getParameter("fileName");

System.out.print("dddddddddd:" + name);
// web絕對路徑
String path = request.getSession().getServletContext().getRealPath("/");
String savePath = path + "upload";

// 設置為下載application/x-download
response.setContentType("application/x-download");
// 即將下載的文件在伺服器上的絕對路徑
String filenamedownload = savePath + "/" + name;
// 下載文件時顯示的文件保存名稱
String filenamedisplay = name;
// 中文編碼轉換
filenamedisplay = URLEncoder.encode(filenamedisplay, "UTF-8");
response.addHeader("Content-Disposition", "attachment;filename="
+ filenamedisplay);
try {
java.io.OutputStream os = response.getOutputStream();
java.io.FileInputStream fis = new java.io.FileInputStream(
filenamedownload);
byte[] b = new byte[1024];
int i = 0;
while ((i = fis.read(b)) > 0) {
os.write(b, 0, i);
}
fis.close();
os.flush();
os.close();
} catch (Exception e) {

}

}

}

2. JSP中的三種注釋

每種編程語言（無論是C / C ++，Java，C#還是.NET）都提供注釋. 文檔和程序中的注釋用於闡明文檔或程序的內容. 注釋不會給程序增加額外的處理開銷，因為編譯器和解釋器將忽略它們. 由於JSP允許用戶在一個頁面中混合Java，JSP和HTML標記，因此JSP頁面中有多種注釋方法. 其中，HTML注釋在JSP編譯的HTML源代碼中可見，並且瀏覽器使我們很容易看到它們. JSP注釋未放置在JSP編譯過程創建的HTML文檔中. 這些注釋不能通過瀏覽器作為頁面源代碼的一部分看到. Java注釋也可以出現在JSP文件的Java部分中，在瀏覽器中也不可見. 這里應該注意，在JSP中包含Java注釋違反了將Java和HTML代碼分開的原則. 下面主要顯示以釋方法: 1. JSP頁面中的HTML注釋. 2. JSP頁面中的一般注釋. 3. JSP頁面中的隱藏注釋. 1. JSP頁面中的HTML注釋SP頁面中的HTML注釋是使用「<; —」和「->;」創建的jsp 注釋快捷鍵，其具體形式如下: <;-Comment content->;當它出現在JSP頁面上時，它不會原樣添加到JSP響應中，而是會出現在生成的HTML代碼中. 這段代碼將發送到瀏覽器，然後瀏覽器負責忽略此注釋.
由於JSP不會簡單地忽略HTML注釋，因此它們可以包含嵌入式動態內容. HTML注釋中的JSP表達式將被計算並執行，並發送到瀏覽器的響應. 2.JSP頁面中的常用注釋JSP頁面中的常用注釋是指以下兩種樣式的注釋方法: <;％//注釋內容％>;<;％/ *評論內容* /％>;上面的兩個注釋將被瀏覽器忽略. 3. JSP頁面中的隱藏注釋. JSP語句中的隱藏注釋嵌入在JSP程序的源代碼中. 使用隱藏評論的目的不是給用戶的. 它可以達到兩個目的. JSP語句中的隱藏注釋的目的之一是為了方便程序設計和開發人員閱讀程序，並增強程序的可讀性. 對於整個項目開發團隊和長期使用而言jsp 注釋快捷鍵，優秀的程序員的良好注釋風格非常重要. JSP語句中的隱藏注釋的第二個目的是在考慮程序系統安全性的同時提高程序的可讀性. 如果用戶通過Web瀏覽器查看JSP頁面，則看不到隱藏注釋中注釋的內容. 使用「<;％-」和「-％>;」創建JSP頁面中的隱藏注釋. 其具體形式如下:<;％-注釋內容-％>;

3. jsp登陸界面源代碼

1、login.jsp文件

<%@ page language="java" contentType="text/html; charset=GB18030"

pageEncoding="GB18030"%>

<%@ page import="java.util.*" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>登錄頁面</title>

</head>

<body>

<form name="loginForm" method="post" action="judgeUser.jsp">

<table>

<tr>

<td>用戶名:<input type="text" name="userName" id="userName"></td>

</tr>

<tr>

<td>密碼:<input type="password" name="password" id="password"></td>

</tr>

<tr>

<td><input type="submit" value="登錄" style="background-color:pink"> <input

type="reset" value="重置" style="background-color:red"></td>

</tr>

</table>

</form>

</body>

</html>

2、judge.jsp文件

<%@ page language="java" contentType="text/html; charset=GB18030"

pageEncoding="GB18030"%>

<%@ page import="java.util.*" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>身份驗證</title>

</head>

<body>

<%

request.setCharacterEncoding("GB18030");

String name = request.getParameter("userName");

String password = request.getParameter("password");

if(name.equals("abc")&& password.equals("123")) {

3、afterLogin.jsp文件

%>

<jsp:forward page="afterLogin.jsp">

<jsp:param name="userName" value="<%=name%>"/>

</jsp:forward>

<%

}

else {

%>

<jsp:forward page="login.jsp"/>

<%

}

%>

</body>

</html>

<%@ page language="java" contentType="text/html; charset=GB18030"

pageEncoding="GB18030"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>登錄成功</title>

</head>

<body>

<%

request.setCharacterEncoding("GB18030");

String name = request.getParameter("userName");

out.println("歡迎你:" + name);

%>

</body>

</html>

(3)jsp項目優秀源碼擴展閱讀：

java web登錄界面源代碼：

1、Data_uil.java文件

import java.sql.*;

public class Data_uil

{

public Connection getConnection()

{

try{

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

}catch(ClassNotFoundException e)

{

e.printStackTrace();

}

String user="***";

String password="***";

String url="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=***";

Connection con=null;

try{

con=DriverManager.getConnection(url,user,password);

}catch(SQLException e)

{

e.printStackTrace();

}

return con;

}

public String selectPassword(String username)

{

Connection connection=getConnection();

String sql="select *from login where username=?";

PreparedStatement preparedStatement=null;

ResultSet result=null;

String password=null;

try{

preparedStatement=connection.prepareStatement(sql);

preparedStatement.setString(1,username);

result=preparedStatement.executeQuery();//可執行的 查詢

if(result.next())

password=result.getString("password");

}catch(SQLException e){

e.printStackTrace();

}finally

{

close(preparedStatement);

close(result);

close(connection);

}

System.out.println("找到的資料庫密碼為："+password);

return password;

}

public void close (Connection con)

{

try{

if(con!=null)

{

con.close();

}

}catch(SQLException e)

{

e.printStackTrace();

}

}

public void close (PreparedStatement preparedStatement)

{

try{

if(preparedStatement!=null)

{

preparedStatement.close();

}

}catch(SQLException e)

{

e.printStackTrace();

}

}

public void close(ResultSet resultSet)

{

try{

if(resultSet!=null)

{

resultSet.close();

}

}catch(SQLException e)

{

e.printStackTrace();

}

}

}

2、login_check.jsp:文件

<%@ page language="java" contentType="text/html; charset=utf-8"

pageEncoding="utf-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

<title>驗證用戶密碼</title>

</head>

<body>

<jsp:useBean id="util" class="util.Data_uil" scope="page" />

<%

String username=(String)request.getParameter("username");

String password=(String)request.getParameter("password");

if(username==null||"".equals(username))

{

out.print("<script language='javaScript'> alert('用戶名不能為空');</script>");

response.setHeader("refresh", "0;url=user_login.jsp");

}

else

{

System.out.println("輸入的用戶名:"+username);

String passwordInDataBase=util.selectPassword(username);

System.out.println("密碼："+passwordInDataBase);

if(passwordInDataBase==null||"".equals(passwordInDataBase))

{

out.print("<script language='javaScript'> alert('用戶名不存在');</script>");

response.setHeader("refresh", "0;url=user_login.jsp");

}

else if(passwordInDataBase.equals(password))

{

out.print("<script language='javaScript'> alert('登錄成功');</script>");

response.setHeader("refresh", "0;url=loginSucces.jsp");

}

else

{

out.print("<script language='javaScript'> alert('密碼錯誤');</script>");

response.setHeader("refresh", "0;url=user_login.jsp");

}

}

%>

</body>

</html>

3、loginSucces.jsp文件

<%@ page language="java" contentType="text/html; charset=utf-8"

pageEncoding="utf-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<title>Insert title here</title>

</head>

<body>

<hr size="10" width="26%" align="left" color="green">

<font size="6" color="red" >登錄成功 </font>

<hr size="10" width="26%" align="left" color="green">

</body>

</html>

4、user_login.jsp文件

<%@ page language="java" contentType="text/html; charset=utf-8"

pageEncoding="utf-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<title>登錄界面</title>

</head>

<body background="C:Userswin8workspaceLoginimage\_10.jpg" >

<center>

<br><br><br><br><br><br>

<h1 style="color:yellow">Login</h1>

<br>

<form name="loginForm" action="login_check.jsp" method="post">

<table Border="0" >

<tr >

<td>賬號</td>

<td><input type="text" name="username"></td>

</tr>

<tr>

<td>密碼</td>

<td><input type="password" name="password">

</td>

</tr>

</table>

<br>

<input type="submit" value="登錄" style="color:#BC8F8F">

</form>

</center>

</body>

</html>