mailconnection.java

基于WINCE5.2的ARM嵌入式手机软件的开发

/*
 * 该类实现了到邮件服务器的连接，提供了send receive等方法
 */

package MobileEmail;
import javax.microedition.io.SocketConnection;
import javax.microedition.io.Connector;
import java.io.*;
/**
 *
 * @author Administrator
 */
public class MailConnection {
    private static final byte CR=0x0D;//回车
    private static final byte LF=0x0A;//换行
    private static final byte[] CRLF={CR,LF};
    private SocketConnection socket;
    private OutputStream os;
    private InputStream is;
    private byte[] buffer=new byte[128];

    public MailConnection(String host,int port) throws IOException{
        socket=(SocketConnection)Connector.open("socket://"+host+":"+port);
        os=socket.openOutputStream();
        is=socket.openInputStream();
    }

    //关闭连接

    public void close() throws IOException{
        if(socket!=null){
            socket.close();
            socket=null;
        }
    }

    public boolean isConnection(){
        return socket!=null;
    }

    //发送字符串s到服务器
    public void send(String s) throws IOException{
        byte[] bytes=s.getBytes();
        int len=bytes.length;
        if(len==0){
            os.write(CRLF, 0, 2);//结束符号
        }
        else{
            int i=0;
            int j=0;
            while(i<len){
                while(j<len&&bytes[j]!=CR&&bytes[j]!=LF){
                    j++;
                }
                os.write(bytes, i, j-1);
                os.write(CRLF, 0, 2);
                if(j<len-1&&bytes[j]==CR&&bytes[j+1]==LF){
                    j++;
                }
                i=++j;
            }
        }
    }

    //接搜服务器返回的字符串 字符串已CRLF为结束标记
    public String receive() throws IOException{
        boolean stop=false;
        int n=-1;
        StringBuffer result=new StringBuffer();
        while(!stop){
            int count=0;
            while(true){
                n=is.read(buffer, count, 1);
                if(n==-1){
                    try{
                       close();
                    }
                    catch(IOException ioe){
                        ioe.printStackTrace();
                        //throws new IOException("连接已经关闭！");
                    }
                    
                }
                else if(n==0){
                    Thread.yield();
                }
                else{
                    byte b=buffer[count];
                    if(b==CR){
                    }
                    else if(b==LF){
                       stop=true;
                       break;
                    }
                    else{
                       count++;
                       if(count>=buffer.length){
                           break;
                       }
                    }
                }
            }
            result.append(new String(buffer,0,count));
        }
        return result.toString();
    }   
}