J2ME Http连接例子（DEMO，示例性源代码）

package com.defonds.http; import java.io.IOException; import java.io.InputStream; import javax.microedition.io.Connector; import javax.microedition.io.HttpConnection; import javax.microedition.lcdui.Command; import javax.microedition.lcdui.CommandListener; import javax.microedition.lcdui.Display; import javax.microedition.lcdui.Displayable; import javax.microedition.lcdui.Form; import javax.microedition.lcdui.Image; import javax.microedition.lcdui.StringItem; import javax.microedition.midlet.MIDlet; /** * HttpDemo * * @author kf156(亚日) * */ public class HttpTest extends MIDlet implements CommandListener, Runnable { public static final byte WAIT = 0;// 等待 public static final byte CONNECT = 1;// 连接中 public static final byte SUCCESS = 2;// 成功 public static final byte FAIL = 3;// 失败 int state;// 当前状态 Display display = Display.getDisplay(this); Form form = new Form("HttpTest"); boolean cmnet = true;// 接入点为cmnet还是cmwap StringBuffer sb = new StringBuffer("当前接入方式为:CMNET\n"); StringItem si = new StringItem(null, sb.toString()); Command connect = new Command("联网", Command.OK, 1); Command change = new Command("改变接入点方式", Command.OK, 2); Command exit = new Command("退出", Command.EXIT, 1); HttpConnection http; String host = "wiki.huihoo.com"; String path = "/images/9/9c/Java.gif"; public HttpTest() { state = WAIT;// 等待状态 form.append(si); form.addCommand(connect); form.addCommand(change); form.addCommand(exit); form.setCommandListener(this); } protected void destroyApp(boolean b) { } protected void pauseApp() { } protected void startApp() { display.setCurrent(form); } public void commandAction(Command c, Displayable d) { if (c == change) {// 改变接入点 if (isConnect()) return; cmnet = !cmnet; form.deleteAll(); sb.delete(0, sb.length()); addStr("当前接入方式为:" + (cmnet ? "CMNET" : "CMWAP")); form.append(si); } else if (c == connect) {// 联网 if (isConnect()) return; new Thread(this).start(); } else if (c == exit) {// 退出 destroyApp(true); notifyDestroyed(); } } public void run() { form.deleteAll(); sb.delete(0, sb.length()); addStr("当前接入方式为:" + (cmnet ? "CMNET" : "CMWAP")); form.append(si); state = CONNECT; addStr("网络连接中..."); InputStream is = null; try { String url = null; url = cmnet ? ("http://" + host + path) : ("http://10.0.0.172:80" + path); http = (HttpConnection) Connector.open(url, Connector.READ_WRITE, true); if (!cmnet) http.setRequestProperty("X-Online-Host", host); http.setRequestMethod(HttpConnection.GET); String contentType = http.getHeaderField("Content-Type"); System.out.println(contentType); addStr(contentType); if (contentType != null && contentType.indexOf("text/vnd.wap.wml") != -1) {// 过滤移动资费页面 addStr("移动资费页面，过滤！"); http.close(); http = null; http = (HttpConnection) Connector.open(url, Connector.READ_WRITE, true); if (!cmnet) http.setRequestProperty("X-Online-Host", host); http.setRequestMethod(HttpConnection.GET); contentType = http.getHeaderField("Content-Type"); } addStr("Content-Type=" + contentType); int code = http.getResponseCode(); addStr("HTTP Code :" + code); if (code == 200) { addStr("网络联网成功，接收数据..."); is = http.openInputStream(); Image image = Image.createImage(is); addStr("数据接收完毕，显示图片"); form.append(image); // 普通字节数据接收 // byte[] b = new byte[1024]; // int len = 0; // ByteArrayOutputStream baos = new ByteArrayOutputStream(); // DataOutputStream dos = new DataOutputStream(baos); // while ((len = is.read(b)) != -1) { // dos.write(b, 0, len); // } // dos.close(); // dos = null; // is.close(); // is = null; state = SUCCESS; return; } else { addStr("访问页面失败"); } } catch (IOException e) { addStr("联网发生异常：" + e.toString()); e.printStackTrace(); } catch (Exception e) { addStr("发生异常：" + e.toString()); e.printStackTrace(); } finally { if (is != null) { try { is.close(); } catch (IOException e) { e.printStackTrace(); } is = null; } if (http != null) try { http.close(); } catch (IOException e) { e.printStackTrace(); } http = null; } state = FAIL; } /** * 判断是否正在连接 * * @return */ private boolean isConnect() { if (state == CONNECT) { addStr("网络连接中，请稍候..."); return true; } return false; } /** * 添加文字 * * @param str * 要添加的文字 */ private void addStr(String str) { sb.append(str + "\n"); si.setText(sb.toString()); } }