一、开发前准备

1、在eclipse中新建一个android app工程

2、打开工程的AndroidManifest.xml文件，加上

android:name="android.permission.INTERNET" />

表示可以访问网络，并将android:minSdkVersion 设置为"11"

3、在主程序进行操作前加上以下代码

StrictMode.setThreadPolicy(new

StrictMode.ThreadPolicy.Builder()

.detectDiskReads()

.detectDiskWrites()

.detectNetwork()

.penaltyLog()

.build());

StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()

.detectLeakedSqlLiteObjects()

.detectLeakedClosableObjects()

.penaltyLog()

.penaltyDeath()

.build());

主要原因是，android4.0以后的版本不允许在主程序中进行联网操作，否则会报如下错误

android.os.NetWorkOnMainException和android.os.NetWorkOnMainThreadException

二、程序中实现

String

httpUrl="要访问的http url地址";

String

resultData="";

URL

url=null;

try{

url=new

URL(httpUrl);

}

catch(MalformedURLException

e){

System.out.println(e.getMessage());

}

if(url!=null){

try{

HttpURLConnection

urlConn=(HttpURLConnection)url.openConnection();

urlConn.setDoOutput(true);

urlConn.setDoInput(true);

urlConn.setRequestMethod("POST");

urlConn.setUseCaches(false);

urlConn.setInstanceFollowRedirects(true);

urlConn.setRequestProperty("contentType",

"GBK");//解决中文显示乱码问题 urlConn.connect();

DataOutputStream

out=new DataOutputStream(urlConn.getOutputStream());

String

content="POST参数名="+URLEncoder.encode("传入值","gb2312");

out.writeBytes(content);

out.flush();

out.close();

BufferedReader

reader=new BufferedReader(new

InputStreamReader(urlConn.getInputStream(),"GBK"));

String

inputLine=null;

while((inputLine=reader.readLine())!=null){

resultData+=inputLine+"\n";

}

reader.close();

urlConn.disconnect();

if(resultData!=""){

System.out.println(resultData);

}else{

System.out.println("Sorry,the

content is null");

}

}

catch(IOException

e){

System.out.println(e.getMessage());

}

}