J2ME通过URL访问XML文件并下载XML到本地

（叶全府）J2ME通过URL访问XML文件并下载XML到本地

2009-06-11 14:45

**      * 网络连接      * 固定URL的网络连接      * @param cmnet      *            true走cmnet false走cmwap      * @return返回String类型的XML数据      */     private String connect( boolean cmnet) {         try {             if (cmnet) {                 http = (HttpConnection) Connector                         .open( http://xx.cn/t.xml );             } else {                 http = (HttpConnection) Connector                         .open( http://10.0.0.3/t.xml );                 http.setRequestProperty( " X-Online-Host " , " xx.cn " );             }             http.setRequestProperty( " Content-Type " , " application/octet-stream " );             http.setRequestProperty( " Connection " , " Keep-Alive " );             http.setRequestMethod(HttpConnection.GET);             // 判断是否为连接网络收费提示页面             String content_type = http.getHeaderField( " Content-Type " );             // 如果是返回移动的拦截页面，则重发．             if (content_type.indexOf( " wml " ) != - 1 ) {                 try {                     http.close();                 } catch (IOException e) {                 }                 http = null ;                 // 重新发起一次请求                 if (cmnet) {                     http = (HttpConnection) Connector                             .open( http://xx.cn/t.xml );                 } else {                     http = (HttpConnection) Connector                             .open( http://10.0.0.3/t.xml );                     http.setRequestProperty( " X-Online-Host " ,                             " xx.cn " );                 }                 http.setRequestMethod(HttpConnection.GET);             }             int code = http.getResponseCode();             if (code == 200 ) { // 返回200 表示连接成功                 // 打开输入流，读取数据                 InputStreamReader is = new InputStreamReader(http                         .openInputStream(), " UTF-8 " );                 // 建一StringBuffer，用于保存已读的数据                 StringBuffer sb = new StringBuffer();                 // 每次读取1K的数据                 char [] c = new char [ 1024 ];                 int k;                 // 循环读取数据，直到读完 当返回-1时表示流已读完                 while ((k = is.read(c)) != - 1 ) {                     sb.append(c, 0 , k);                 }                 is.close();                 is = null ;                 http.close();                 http = null ;                 return sb.toString();             }         } catch (Exception e) {             e.printStackTrace();             // return null;         } finally {             if (http != null ) {                 try {                     http.close();                     http = null ;                 } catch (IOException e) {                 }                 http = null ;             }         }         return null ;     }