Android学习笔记（十二）-WebService调用

在J2EE项目中，我们可以根据WSDL通过各种框架来直接生成WebService的客户端调用代码，在Android中，也有第三方的框架可用于调用WebService，这里介绍一种通过使用HTTP协议来模拟WebService调用过程的方法，即自己根据规范来构建请求的XML，然后通过HTTP协议发送，最后自己解析响应的XML。

这里以一个获得国内手机号码归属地数据库信息的WebService为例：

http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx

SSOAP 1.2

以下是 SOAP 1.2 请求和响应示例。所显示的占位符需替换为实际值。

POST /WebServices/MobileCodeWS.asmx HTTP/1.1
Host: webservice.webxml.com.cn
Content-Type: application/soap+xml; charset=utf-8
Content-Length: length

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<getMobileCodeInfo xmlns="http://WebXml.com.cn/">
<mobileCode>string</mobileCode>
<userID>string</userID>
</getMobileCodeInfo>
</soap12:Body>
</soap12:Envelope>

HTTP/1.1 200 OK
Content-Type: application/soap+xml; charset=utf-8
Content-Length: length

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<getMobileCodeInfoResponse xmlns="http://WebXml.com.cn/">
<getMobileCodeInfoResult>string</getMobileCodeInfoResult>
</getMobileCodeInfoResponse>
</soap12:Body>
</soap12:Envelope>

[/code]
首先是要构建请求的XML，可以采用Pull方式来构建，这里采用正则表达式的方式来替换字符串，这样更简单一些。

在src下建立一个mobilesoap.xml文件

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<getMobileCodeInfo xmlns="http://WebXml.com.cn/">
<mobileCode>$mobile</mobileCode>
<userID></userID>
</getMobileCodeInfo>
</soap12:Body>
</soap12:Envelope>

使用正则表达式将$mobile替换成实际的手机号即可。

至于返回的XML可以使用Pull方式来解析。

项目运行效果如下：



布局文件：layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/mobile" />

<EditText
android:id="@+id/mobile"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />

<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/button" />

<TextView
android:id="@+id/address"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />

</LinearLayout>

数据文件：values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, MobileAddressActivity!</string>
<string name="app_name">手机号归属地查询</string>
<string name="mobile">手机号</string>
<string name="button">查询</string>
</resources>

MobileAddressActivity.java

package com.android.ws;

import java.io.InputStream;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.android.service.MobileService;

public class MobileAddressActivity extends Activity {
private EditText mobileText;
private TextView addressView;
private static final String TAG = "MainActivity";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

mobileText = (EditText)this.findViewById(R.id.mobile);
addressView = (TextView)this.findViewById(R.id.address);
Button button = (Button)this.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String mobile = mobileText.getText().toString();
InputStream inStream = this.getClass().getClassLoader().getResourceAsStream("mobilesoap.xml");
try {
addressView.setText(MobileService.getMobileAddress(inStream, mobile));
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
Toast.makeText(MobileAddressActivity.this, "查询失败", 1).show();
}
}
});
}
}

MobileService.java

package com.android.service;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.xmlpull.v1.XmlPullParser;

import android.util.Xml;

import com.android.utils.StreamTool;

public class MobileService {
private static String readSoapFile(InputStream inStream, String mobile) throws Exception{
byte[] data = StreamTool.readInputStream(inStream);
String soapxml = new String(data);
Map<String, String> params = new HashMap<String, String>();
params.put("mobile", mobile);
return replace(soapxml, params);
}

public static String replace(String xml, Map<String, String> params)throws Exception{
String result = xml;
if(params!=null && !params.isEmpty()){
for(Map.Entry<String, String> entry : params.entrySet()){
String name = "\\{1}quot;+ entry.getKey();
Pattern pattern = Pattern.compile(name);
Matcher matcher = pattern.matcher(result);
if(matcher.find()){
result = matcher.replaceAll(entry.getValue());
}
}
}
return result;
}

public static String getMobileAddress(InputStream inStream, String mobile)throws Exception{
String soap = readSoapFile(inStream, mobile);
byte[] data = soap.getBytes();
URL url = new URL("http://webservice.webxml.com.cn/WebServices/MobileCodeWS.asmx");
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setConnectTimeout(5 * 1000);
conn.setDoOutput(true);//如果通过post提交数据，必须设置允许对外输出数据
conn.setRequestProperty("Content-Type", "application/soap+xml; charset=utf-8");
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
OutputStream outStream = conn.getOutputStream();
outStream.write(data);
outStream.flush();
outStream.close();
if(conn.getResponseCode()==200){
return parseResponseXML(conn.getInputStream());
}
return null;
}

private static String parseResponseXML(InputStream inStream) throws Exception{
XmlPullParser parser = Xml.newPullParser();
parser.setInput(inStream, "UTF-8");
int eventType = parser.getEventType();//产生第一个事件
while(eventType != XmlPullParser.END_DOCUMENT){//只要不是文档结束事件
switch (eventType) {
case XmlPullParser.START_TAG:
String name = parser.getName();//获取解析器当前指向的元素的名称
if("getMobileCodeInfoResult".equals(name)){
return parser.nextText();
}
break;
}
eventType = parser.next();
}
return null;
}

}

StreamTool.java

package com.android.utils;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class StreamTool {

/**
* 从输入流中读取数据
* @param is 输入流
* @return
* @throws Exception
*/
public static byte[] readInputStream(InputStream is) throws Exception{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int len = 0;
while((len = is.read(buf)) != -1){
baos.write(buf, 0, len);
}
baos.flush();
baos.close();

return baos.toByteArray();
}
}

另外需要在AndroidManifest.xml中添加网络访问权限：

<!-- 访问网络的权限 -->

<uses-permission android:name="android.permission.INTERNET"/>