Android中Apache包介绍

Apache包是对android联网访问封装的很好的一个包，也是android访问网络最常用的类。

下面分别讲一下怎么用HttpClient实现get，post请求。

1.Get 请求

HttpGet get = new HttpGet("http://www.baidu.com");

HttpClient hClient = new DefaultHttpClient();

httpResponse = hClient.execute(get);

2.Post 请求

Map<String, String> map = new HashMap<String, String>();

map.put("id", id);

map.put("name", name);

map.put("permission", String.valueOf(permission));

List<NameValuePair> list = new ArrayList<NameValuePair>();

if(map != null && !map.isEmpty()){

for(Map.Entry<String, String> entry : map.entrySet()){//迭代器

//键值对

NameValuePair nameValuePair = new BasicNameValuePair(entry.getKey(), entry.getValue());

list.add(nameValuePair);

}

}

UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list ,encode);

//使用post方式提交数据

HttpPost post = new HttpPost(path);

post.setEntity(entity);//请求体中

//默认客户端

HttpClient client = httpClient;

HttpResponse httpResponse = client.execute(post);

3.代码实例：

先是get请求

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.DefaultHttpClientConnection;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

private Button requestButton;
private HttpResponse httpResponse;
private HttpEntity entity;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
requestButton = (Button) findViewById(R.id.requestButton);

requestButton.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
new Thread(new Downtest()).start();
}
});
}
class Downtest implements Runnable{

public void run() {
//生成一个请求对象,请求
HttpGet get = new HttpGet("http://www.baidu.com");
//生成一个Http客户端对象
HttpClient hClient = new DefaultHttpClient();
//使用Http客户端发送请求对象
InputStream inputStream = null;
try {
httpResponse = hClient.execute(get);//httpResponse返回的响应
//返回的响应数据就放在里边
entity = httpResponse.getEntity();
inputStream = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String result = "";
String line = "";
while((line = reader.readLine())!= null){
result = result+ line;
}
System.out.println(result);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try{
inputStream.close();
}catch(Exception e){
e.printStackTrace();
}
}
}
}

}

再是post请求

public class AccountHttpUtils {

//private static String PATH = "http://192.168.253.1:8088/CallName/servlet/AccountServler";
private static HttpClient httpClient;
public AccountHttpUtils(HttpClient httpClient) {
this.httpClient = httpClient;
}
public static String sendHttpClient(String path,Map<String,String> map,String encode){
List<NameValuePair> list = new ArrayList<NameValuePair>();
if(map != null && !map.isEmpty()){
for(Map.Entry<String, String> entry : map.entrySet()){//迭代器
//键值对
NameValuePair nameValuePair = new BasicNameValuePair(entry.getKey(), entry.getValue());
list.add(nameValuePair);
}
}
try {
//实现将请求的参数封装到表单中，
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list ,encode);
//使用post方式提交数据
HttpPost post = new HttpPost(path);
post.setEntity(entity);//请求体中
//默认客户端
HttpClient client = httpClient;

HttpResponse httpResponse = client.execute(post);
if(httpResponse.getStatusLine().getStatusCode() == 200){
HttpEntity httpEntity = httpResponse.getEntity();
InputStream inputStream = httpEntity.getContent();
return changeInputeStream(inputStream, encode);
}
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return "";
}
/**
* 将一个输入流转换成字符串
* @param inputStream
* @param encode
* @return
*/
private static String changeInputeStream(InputStream inputStream,String encode) {
//通常叫做内存流，写在内存中的
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] data = new byte[1024];
int len = 0;
String result = "";
if(inputStream != null){
try {
while((len = inputStream.read(data))!=-1){
data.toString();
outputStream.write(data, 0, len);
}
//result是在服务器端设置的doPost函数中的
result = new String(outputStream.toByteArray(),encode);
outputStream.flush();
outputStream.close();
inputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return result;
}
public static String set(String id,String name,int permission) {
// TODO Auto-generated method stub
Map<String, String> map = new HashMap<String, String>();
map.put("id", id);
map.put("name", name);
map.put("permission", String.valueOf(permission));
String result = AccountHttpUtils.sendHttpClient(AbstractHttpUtils.PATH+"servlet/AccountServler", map, "utf-8");
System.out.println("result:"+ result);
return result;
}

}

4.get请求访问的是百度，返回的是百度首页的源代码

post是我的一个小项目中的类

不过结构已经很清晰啦。。。。