Flex+blazeds实现与MySQL数据库的连接 -----RemoteObject方式数据库连接
刚刚学习flex不久,这个小例子通过remoteobject的通讯方法。实现flex与mySQL数据库的交互。
使用mySQL中的test数据库
建表名为admin.表中字段为: id username userpwd (最终目的:将数据库表中的记录最终显示在flex端的DateGrid组件中显示出来)
建立myEclipse的工程
新建->web project 输入工程名后。需要将事先下载的Blazeds包粘贴至工程目录下。并且将mysql的驱动放到工程目录lib的文件夹下
(我使用版本blazeds-turnkey-3.2.0.3978.zip。把blazeds.war解压,将得到的META-INF和WEB-INF两个文件夹拷入我们发布web工程下覆盖)
代码部分
ConnectionHelper.java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnectionHelper
{
private String url;
private static ConnectionHelper instance;
private ConnectionHelper()
{
try {
Class.forName("com.mysql.jdbc.Driver");
url =
"jdbc:MySQL://localhost/test";
} catch (Exception e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException {
if (instance == null) {
instance = new ConnectionHelper();
}
try {
return
DriverManager.getConnection(instance.url,"root","root");
} catch (SQLException e) {
throw e;
}
}
public static void close(Connection connection)
{
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
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DAOException.java
public class DAOException extends RuntimeException
{
static final long serialVersionUID = -1881205326938716446L;
public DAOException(String message)
{
super(message);
}
public DAOException(Throwable cause)
{
super(cause);
}
public DAOException(String message, Throwable cause)
{
super(message, cause);
}
}
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以上是数据库连接所需方法。然后根据数据库中表的结构写下所需的方法类
Admin.java
import java.io.Serializable;
public class Admin implements Serializable {
static final long serialVersionUID = 103844514947365244L;
private int id;
private String username;
private String userpwd;
public Admin() {
}
public Admin(int id,String username,String userpwd) {
this.id = id;
this.username=username;
this.userpwd=userpwd;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUserpwd() {
return userpwd;
}
public void setUserpwd(String userpwd) {
this.userpwd = userpwd;
}
}
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AdminService.java
import java.util.ArrayList;
import java.util.List;
import java.sql.*;
import flex.jie.ConnectionHelper;
import flex.jie.DAOException;
public class AdminService {
public List getAdmins() throws DAOException {
List list = new ArrayList();
Connection c = null;
try {
c =
ConnectionHelper.getConnection();
Statement s = c.createStatement();
ResultSet rs = s.executeQuery("SELECT
* FROM admin ORDER BY id");
while (rs.next()) {
list.add(new
Admin(rs.getInt("id"),
rs.getString("username"),
rs.getString("userpwd")));
}
} catch (SQLException e) {
e.printStackTrace();
throw new DAOException(e);
} finally {
ConnectionHelper.close(c);
}
return list;
}
}
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重要一步:
在remoting-config.xml文件中
添加(source处根据实际的建包名填写)
<destination id="admin">
<properties>
<source>flex.jie.user.AdminService</source>
</properties>
</destination>
至此。myEclipse工程中所需代码以及配置已经完成。将工程部署并发布在Tomacat下面。
接下来,flex端的步骤。
首先 新建Flex
Project ,输入工程名。在server technology处选择J2EE,点击next
填写刚刚发布在tomcat下的目录名。点击完成。
在默认的mxml中的代码如下:
index.mxml
<?xml version="1.0"
encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
backgroundColor="#FFFFFF">
<mx:RemoteObject id="srv"
destination="admin"/>
<mx:DataGrid
dataProvider="{srv.getAdmins.lastResult}" width="100%"
height="100%"/>
<mx:Button label="Get Data"
click="srv.getAdmins()"/>
</mx:Application>
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在tomcat启动的前提下,点击运行即可。
或者想显示指定的列。只需要稍作修改即可
<?xml version="1.0"
encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
backgroundColor="#FFFFFF"
creationComplete="srv.getAdmins()">
<mx:Script>
<![CDATA[
import mx.rpc.events.ResultEvent;
import mx.collections.ArrayCollection;
[Bindable]public var ad:ArrayCollection;
private function
adminHandler(event:ResultEvent):void
{
ad= event.result as
ArrayCollection
}
]]>
</mx:Script>
<mx:RemoteObject id="srv"
destination="admin">
<mx:method name="getAdmins"
result="adminHandler(event)"/>
</mx:RemoteObject>
<mx:DataGrid dataProvider="{ad}">
<mx:columns>
<mx:DataGridColumn
headerText="用户名"
dataField="username"/>
<mx:DataGridColumn
headerText="密码"
dataField="userpwd"/>
</mx:columns>
</mx:DataGrid>
</mx:Application>
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说明:此时的destination对应remote-config.xml中的id号
。建立连接。从而flex端所用到的java方法可以找到。返回数据库中所建表的信息。