《FLex调用servlet连接数据库详解》pdf电子书免费下载
下载方式一：
百度网盘下载地址：https://pan.baidu.com/s/1q64SdpQoL9dw-8678LghlQ
百度网盘密码：1111
下载方式二：
http://ziliaoshare.cn/Download/ae_123518_do_FLexDYservletLJSJKXJ.zip
|
|
作者：empty 出版社：empty |
《FLex调用servlet连接数据库详解》介绍
FLex调用servlet连接数据库
前言
Flex 最重要的部分之一就是和服务器以及数据库的通讯。Flex 提供了三个类来与服务器通讯： HTTPService，RemoteObject 以及WebService。
HTTPService 类提供了使用超文本传输协议（HTTP）与服务器通讯的方式。一个Flex 应用程序可以使用GET 或者POST 请求来发送数据到一个服务器并且处理这个请求返回的 XML 或者字符串。使用HTTPService 类，你可以与PHP 页面,ColdFusion 页面，JavaServe页面（ jsp），Java servlet， Ruby onRails， 以及ASP 动态网页通讯。
与Java Servlet通讯
由于本人是Java出身，所以这里就来讨论一下与Servlet的通讯方式。
建立数据库
这里选用MySql数据库，首先建立如下的数据库表
写服务器端Java代码
Servlet
view plaincopy to clipboardprint?
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import PODO.Product;
import db.ProductDao;
public class GetProductServlet extends HttpServlet {
List result;
/**
* Constructor of the object.
*/
public GetProductServlet() {
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 {
result = new ProductDao().getProduct();
String xmlContent = ?xml version='1.0' encoding='utf-8'?> products> ;
response.setContentType( text/xml;charset=utf-8 );
PrintWriter out = response.getWriter();
if (result != null) {
for (int i = 0; i result.size(); i++) {
Product p = (Product) result.get(i);
xmlContent += product> name> + p.getName() + /name> type>
+ p.getType() + /type> price> + p.getPrice()
+ /price> num> + p.getNum() + /num> /product> ;
}
xmlContent += /products> ;
out.print(xmlContent);
out.flush();
out.close();
}
}
/**
* 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 {
this.doGet(request, response);
}
/**
* Initialization of the servlet. br>
*
* @throws ServletException
* if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import PODO.Product;
import db.ProductDao;
public class GetProductServlet extends HttpServlet {
List result;
/**
* Constructor of the object.
*/
public GetProductServlet() {
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 {
result = new ProductDao().getProduct();
String xmlContent = ?xml version='1.0' encoding='utf-8'?> products> ;
response.setContentType( text/xml;charset=utf-8 );
PrintWriter out = response.getWriter();
if (result != null) {
for (int i = 0; i result.size(); i++) {
Product p = (Product) result.get(i);
xmlContent += product> name> + p.getName() + /name> type>
+ p.getType() + /type> price> + p.getPrice()
+ /price> num> + p.getNum() + /num> /product> ;
}
xmlContent += /products> ;
out.print(xmlContent);
out.flush();
out.close();
}
}
/**
* 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 {
this.doGet(request, response);
}
/**
* Initialization of the servlet. br>
*
* @throws ServletException
* if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
数据库连接
view plaincopy to clipboardprint?
public class MyConnection {
public Connection conn = null;
public MyConnection() {
try {
// 注册数据库驱动程序为MYSQL驱动
Class.forName( com.mysql.jdbc.Driver );
} catch (java.lang.ClassNotFoundException e) {
System.err.println( mydb(): + e.getMessage());
}
try {
conn = DriverManager.getConnection(
jdbc:mysql://127.0.0.1:3306/flex ,
root , root );
} catch (SQLException ex) {
System.err.println( conn: + ex.getMessage());
}
}
public Connection getDbConnection() {
return conn;
}
}
public class MyConnection {
public Connection conn = null;
public MyConnection() {
try {
// 注册数据库驱动程序为MYSQL驱动
Class.forName( com.mysql.jdbc.Driver );
} catch (java.lang.ClassNotFoundException e) {
System.err.println( mydb(): + e.getMessage());
}
try {
conn = DriverManager.getConnection(
jdbc:mysql://127.0.0.1:3306/flex ,
root , root );
} catch (SQLException ex) {
System.err.println( conn: + ex.getMessage());
}
}
public Connection getDbConnection() {
return conn;
}
}
DAO
view plaincopy to clipboardprint?
public class ProductDao {
Connection conn;
ResultSet rs;
Statement stmt;
public ProductDao() {
conn = new MyConnection().getDbConnection();
try {
stmt = conn.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public List getProduct() {
List list = new ArrayList();
try {
String sql = select * from product ;
rs = stmt.executeQuery(sql);
while (rs.next()) {
String name=rs.getString( name );
String type=rs.getString( type );
double price=Double.parseDouble(rs.getString( price ));
int num=Integer.parseInt(rs.getString( num ));
Product p=new Product(name,type,price,num);
list.add(p);
}
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
return list;
}
}
}
public class ProductDao {
Connection conn;
ResultSet rs;
Statement stmt;
public ProductDao() {
conn = new MyConnection().getDbConnection();
try {
stmt = conn.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public List getProduct() {
List list = new ArrayList();
try {
String sql = select * from product ;
rs = stmt.executeQuery(sql);
while (rs.next()) {
String name=rs.getString( name );
String type=rs.getString( type );
double price=Double.parseDouble(rs.getString( price ));
int num=Integer.parseInt(rs.getString( num ));
Product p=new Product(name,type,price,num);
list.add(p);
}
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
return list;
}
}
}
PODO
view plaincopy to clipboardprint?
public class Product {
private String name;
private String type;
private double price;
private int num;
public Product(String name, String type, double price, int num) {
this.name = name;
this.type = type;
this.price = price;
this.num = num;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
}
public class Product {
private String name;
private String type;
private double price;
private int num;
public Product(String name, String type, double price, int num) {
this.name = name;
this.type = type;
this.price = price;
this.num = num;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
}
部署TOMCAT
这一部分略过，如果觉得手动部署比较麻烦，我们可以使用MyEclipse插件。值得注意的是web.xml文件的配置，一定要正确配置servlet,下面我给出正确示例
view plaincopy to clipboardprint?
?xml version= 1.0 encoding= UTF-8 ?>
web-app version= 2.4 xmlns= http://java.sun.com/xml/ns/j2ee
xmlns:xsi= http://www.w3.org/2001/XMLSchema-instance xsi:schemaLocation= http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd >
display-name>Benson /display-name>
servlet>
description>This is the description /description>
display-name>This is the display name /display-name>
servlet-name>GetProductServlet /servlet-name>
servlet-class>servlet.GetProductServlet /servlet-class>
/servlet>
servlet-mapping>
servlet-name>GetProductServlet /servlet-name>
url-pattern>/servlet/GetProductServlet /url-pattern>
/servlet-mapping>
welcome-file-list>
welcome-file>index.jsp /welcome-file>
/welcome-file-list>
login-config>
auth-method>BASIC /auth-method>
/login-config>
/web-app>
?xml version= 1.0 encoding= UTF-8 ?>
web-app version= 2.4 xmlns= http://java.sun.com/xml/ns/j2ee
xmlns:xsi= http://www.w3.org/2001/XMLSchema-instance xsi:schemaLocation= http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd >
display-name>Benson /display-name>
servlet>
description>This is the description /description>
display-name>This is the display name /display-name>
servlet-name>GetProductServlet /servlet-name>
servlet-class>servlet.GetProductServlet /servlet-class>
/servlet>
servlet-mapping>
servlet-name>GetProductServlet /servlet-name>
url-pattern>/servlet/GetProductServlet /url-pattern>
/servlet-mapping>
welcome-file-list>
welcome-file>index.jsp /welcome-file>
/welcome-file-list>
login-config>
auth-method>BASIC /auth-method>
/login-config>
/web-app>
编写FLEX MXML
view plaincopy to clipboardprint?
?xml version= 1.0 encoding= utf-8 ?>
mx:Application xmlns:mx= http://www.adobe.com/2006/mxml layout= absolute creationComplete= send() >
mx:HTTPService id= service url= http://localhost:8080/servlet/servlet/GetProductServlet method= GET />
mx:Script>
!--[CDATA[
private function send():void{
//发送请求
service.send();
}
]]-->
/mx:Script>
mx:Canvas x= 0 y= 0 width= 100% height= 100% >
mx:DataGrid x= 0 y= 68 width= 676 height= 383 id= productdata dataProvider= {service.lastResult.products.product} fontFamily= Times New Roman fontSize= 16 >
mx:columns>
mx:DataGridColumn headerText= 商品名称 dataField= name />
mx:DataGridColumn headerText= 商品类别 dataField= type />
mx:DataGridColumn headerText= 商品价格 dataField= price />
mx:DataGridColumn headerText= 剩余数量 dataField= num />
/mx:columns>
/mx:DataGrid>
mx:ApplicationControlBar x= 0 y= 0 height= 70 width= 676 >
/mx:ApplicationControlBar>
/mx:Canvas>
/mx:Application>
?xml version= 1.0 encoding= utf-8 ?>
mx:Application xmlns:mx= http://www.adobe.com/2006/mxml layout= absolute creationComplete= send() >
mx:HTTPService id= service url= http://localhost:8080/servlet/servlet/GetProductServlet method= GET />
mx:Script>
!--[CDATA[
private function send():void{
//发送请求
service.send();
}
]]-->
/mx:Script>
mx:Canvas x= 0 y= 0 width= 100% height= 100% >
mx:DataGrid x= 0 y= 68 width= 676 height= 383 id= productdata dataProvider= {service.lastResult.products.product} fontFamily= Times New Roman fontSize= 16 >
mx:columns>
mx:DataGridColumn headerText= 商品名称 dataField= name />
mx:DataGridColumn headerText= 商品类别 dataField= type />
mx:DataGridColumn headerText= 商品价格 dataField= price />
mx:DataGridColumn headerText= 剩余数量 dataField= num />
/mx:columns>
/mx:DataGrid>
mx:ApplicationControlBar x= 0 y= 0 height= 70 width= 676 >
/mx:ApplicationControlBar>
/mx:Canvas>
/mx:Application>
代码重点解释
1. creationComplete= send()
表明当这个Flex应用创建完成时，就发送这个HttpServer请求给Servlet
2. url=http://localhost:8080/servlet/servlet/GetProductServlet
第一个servlet是我们服务器端的工程名
第二个servelt是servlet所在包名
GetProductServlet使我们真正的servlet名称
3. dataProvider= {service.lastResult.products.product}
a. lastResult：在做了一个呼叫到一个HTTPService 之后，数据会从服务返回，并被放置到服务组件所包含的lastResult 对象。
b. 由于我们返回的是一个XML数据，所以service.lastResult.products.product就代表返回XML中products标签下的所有product标签内容。
c. Product子标签和Flex中 mx:columns>的dataField属性相对应。
结果图
完整的JAVA和FLEX代码可以在这里下载