分享一个实用的网络连接类
手机开发中常常需要用到网络连接发送数据，像web一样，手机中的请求也有GET请求和POST请求之分。
以下是一个HttpProcess类，它提供了POST和GET请求的方式。
package com.thinkrace.UCHome.network;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
/**
*
* @author Administrator
*/
public class HttpProcess {
/**
* HTTP GET请求方式
* 此方法读取返回的xml时是一个字符一个字符读取的。
* @param url
* @return
*/
public static String HttpGET(String url) {
String content = null;
try {
//打开网络连接
HttpConnection hc = (HttpConnection) Connector.open(url);
hc.setRequestMethod(HttpConnection.GET);
InputStreamReader isr = new InputStreamReader(hc.openInputStream(), "UTF-8");
int ch = 0;
StringBuffer buf = new StringBuffer();
while ((ch = isr.read()) != -1) {
buf.append((char) ch);
}
//关闭流
isr.close();
hc.close();
} catch (IOException ex) {
System.out.println("HttpGET方法出现异常");
ex.printStackTrace();
}
return content;
}
/**
* 分配固定内存的GET请求，无论返回的xml有多大，总是只显示5k
* 超出的部分会被截断，剩余的将会用空白补齐
* @param url
* @return
*/
public static String HttpGETByAssignMemory(String url) {
String content = null;
try {
HttpConnection hc = (HttpConnection) Connector.open(url);
hc.setRequestMethod(HttpConnection.GET);
DataInputStream dis = new DataInputStream(hc.openDataInputStream());
//分配5K的内存
byte[] data = new byte[1024 * 5];
dis.read(data);
content = new String(data, "UTF-8");
} catch (IOException ex) {
System.out.println("HttpGETByAllocateMemory方法出现异常");
ex.printStackTrace();
}
return content;
}
public static String HttpPOST(String url, String argument) {
String xml = null;
try {
HttpConnection hc = (HttpConnection) Connector.open(url, Connector.READ_WRITE);
hc.setRequestMethod(HttpConnection.POST);
//设置POST的头信息,UserAgent(设置代理)，Content-Language(语言)，Content-Type(类型)，Content-Length(POST的长度)
hc.setRequestProperty("User-Agent", "Profile/MIDP-2.0 Configuration/CLDC-1.1");
hc.setRequestProperty("Content-Language", "en-US");
hc.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
byte[] postData = argument.getBytes("UTF-8");
hc.setRequestProperty("Content-Length",
Integer.toString(postData != null ? postData.length : 0));
OutputStream out = hc.openOutputStream();
out.write(postData);
InputStream in = hc.openInputStream();
DataInputStream dis = new DataInputStream(in);
int ch = 0;
StringBuffer buf = new StringBuffer();
while((ch = dis.read()) != -1){
buf.append((char)ch);
}
xml = buf.toString();
} catch (IOException ex) {
System.out.println("HttpPOST方法出现异常");
ex.printStackTrace();
}
return xml;
}
/**
* String转换成byte数组
* @param str
* @return
*/
public static byte[] StringtoBytes(String str) {
byte[] data = null;
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
dos.writeUTF(str);
data = baos.toByteArray();
baos.close();
dos.close();
} catch (Exception ex) {
System.out.println("StringtoBytes方法出现异常");
ex.printStackTrace();
}
return data;
}
/**
* byte[]数组转换成String
* @param data
* @return
*/
public static String BytesToString(byte[] data) {
ByteArrayInputStream bais = new ByteArrayInputStream(data);
DataInputStream dis = new DataInputStream(bais);
String str = null;
try {
str = dis.readUTF();
bais.close();
dis.close();
} catch (Exception ex) {
System.out.println("BytesToString方法出现异常");
ex.printStackTrace();
}
return str;
}
}
以下载一张小图片为例子，一个较为简单的HTTP连接的demo。
支持CMNET及CMWAP两种不同的接入方式，以及在CMWAP接入方式下，过滤移动资费页面。
在6120c上测试通过。
以下载一张小图片为例子，一个较为简单的HTTP连接的demo。
支持CMNET及CMWAP两种不同的接入方式，以及在CMWAP接入方式下，过滤移动资费页面。
在6120c上测试通过。
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());
}
}
