在无线J2ME设备上实现超文本传输协议
2006-8-7 14:33:00 文/javajia 出处:javajia
// 用于提交请求的图形用户接口组件
private List list;
private String[] menuItems;
// 用于显示服务器响应的图形用户接口组件
private Form resultScreen;
private StringItem resultField;
//用于requestScreen的"send"按钮
Command sendCommand;
// 用于requestScreen的"exit"按钮
Command exitCommand;
// 用于requestScreen的"back"按钮
Command backCommand;
public HttpMidlet(){
// 初始化图形用户接口组件
myDisplay = Display.getDisplay( this );
sendCommand = new Command( "SEND", Command.OK, 1 );
exitCommand = new Command( "EXIT", Command.OK, 1 );
backCommand = new Command( "BACK", Command.OK, 1 );
//显示请求的URL
requestScreen = new Form( "Type in a URL:" );
requestField = new TextField( null, defaultURL, 100, TextField.URL );
requestScreen.append( requestField );
requestScreen.addCommand( sendCommand );
requestScreen.addCommand( exitCommand );
requestScreen.setCommandListener( this );
// 选择想要的HTTP请求方法
menuItems = new String[] {"GET Request", "POST Request"};
list = new List( "Select an HTTP method:", List.IMPLICIT, menuItems, null );
list.setCommandListener( this );
// 先是从服务器上收到的信息
resultScreen = new Form( "Server Response:" );
resultScreen.addCommand( backCommand );
resultScreen.setCommandListener( this );
}//结束HttpMidlet()
public void startApp() {
myDisplay.setCurrent( requestScreen );
}//结束 startApp()
public void commandAction( Command com, Displayable disp ) {
// 当用户点击"send"按钮
if ( com == sendCommand ) {
myDisplay.setCurrent( list );
} else if ( com == backCommand ) {
requestField.setString( defaultURL );
myDisplay.setCurrent( requestScreen );
} else if ( com == exitCommand ) {
destroyApp( true );
notifyDestroyed();
}//结束 if ( com == sendCommand )
if ( disp == list && com == List.SELECT_COMMAND ) {
String result;
if ( list.getSelectedIndex() == 0 ) // 发送一个 GET 请求到服务器
result = sendHttpGet( requestField.getString() );
else // 发送一个 POST 请求到服务器
result = sendHttpPost( requestField.getString() );
resultField = new StringItem( null, result );
resultScreen.append( resultField );
myDisplay.setCurrent( resultScreen );
}//结束if ( dis == list && com == List.SELECT_COMMAND )
}//结束 commandAction( Command, Displayable )
private String sendHttpGet( String url )
{
HttpConnection hcon = null;
DataInputStream dis = null;
StringBuffer responseMessage = new StringBuffer();
try {
//使用READ权限的标准的 HttpConnection
hcon = ( HttpConnection )Connector.open( url );
//从HttpConnection取得一个 DataInputStream
dis = new DataInputStream( hcon.openInputStream() );