JAVA網路程式設計之模擬表單提交
阿新 • • 發佈：2019-01-09
這一篇部落格是對上一篇《JAVA網路程式設計之獲取網路資源》的擴充，這一篇將使用HttpURLConnection來模擬一個表單的提交。在B/S架構的系統中，請求時通過瀏覽器與服務端進行互動的，提交請求引數時使用form表單進行提交，但是有很多時候，我們需要在程式中直接呼叫HTTP介面，同時需要傳遞一些引數，那麼這個時候我們就可以通過使用HttpURLConnection來模擬表單的提交過程。
首先，我們可以對請求進行封裝
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import 在HttpRequest類中，包含了一個請求的基本資訊，然後我們再封裝一個類用於HTTP的請求。
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
/**
* Http請求客戶端
*
* @author jianggujin
*
*/
public abstract class HttpClient
{
/** 連線超時時間 **/
private int connectTimeOut = 10 * 1000;
/** 讀超時時間 **/
private int readTimeOut = 10 * 1000;
/**
* 獲得連線超時時間
*
* @return
*/
public int getConnectTimeOut()
{
return connectTimeOut;
}
/**
* 設定連線超時發時間
*
* @param connectTimeOut
*/
public void setConnectTimeOut(int connectTimeOut)
{
this.connectTimeOut = connectTimeOut;
}
/**
* 獲得讀超時時間
*
* @return
*/
public int getReadTimeOut()
{
return readTimeOut;
}
/**
* 設定讀超時時間
*
* @param readTimeOut
*/
public void setReadTimeOut(int readTimeOut)
{
this.readTimeOut = readTimeOut;
}
/**
* 執行
*/
public void execute(HttpRequest request) throws IOException
{
String url = request.getUrl();
// GET方式請求
if (request.getMethod() == RequestMethod.GET)
{
// 拼接引數
if (url.indexOf('?') != -1)
{
if (url.endsWith("?"))
{
url += dealParam(request);
}
else
{
if (url.endsWith("&"))
{
url += dealParam(request);
}
else
{
url += ("&" + dealParam(request));
}
}
}
else
{
url += ("?" + dealParam(request));
}
}
// 獲得Http連線
HttpURLConnection connection = (HttpURLConnection) new URL(url)
.openConnection();
// 設定超時時間
connection.setConnectTimeout(connectTimeOut);
connection.setReadTimeout(readTimeOut);
// 設定請求頭
Iterator<Entry<String, String>> headers = request.getHeaders();
while (headers.hasNext())
{
Entry<String, String> entry = headers.next();
connection.setRequestProperty(entry.getKey(), entry.getValue());
}
connection.setUseCaches(false);
// 如果是POST請求
if (request.getMethod() == RequestMethod.POST)
{
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setRequestMethod("POST");
}
connection.connect();
// 如果是POST請求
if (request.getMethod() == RequestMethod.POST)
{
OutputStreamWriter writer = new OutputStreamWriter(
connection.getOutputStream(), request.getCharset());
writer.write(dealParam(request));
writer.flush();
writer.close();
}
if (connection.getResponseCode() == HttpURLConnection.HTTP_OK)
{
onSuccess(HttpURLConnection.HTTP_OK, connection.getInputStream());
}
else
{
onSuccess(connection.getResponseCode(), connection.getErrorStream());
}
connection.disconnect();
}
/**
* 處理請求引數
*
* @param request
* @return
* @throws IOException
*/
private String dealParam(HttpRequest request) throws IOException
{
StringBuilder builder = new StringBuilder();
Iterator<Entry<String, List<String>>> iterator = request.getParams();
int count = 0;
// 遍歷請求引數
while (iterator.hasNext())
{
Entry<String, List<String>> entry = iterator.next();
List<String> list = entry.getValue();
for (String string : list)
{
if (count > 0)
{
builder.append("&");
}
builder.append(entry.getKey()).append("=");
if (request.getMethod() == RequestMethod.GET)
{
builder.append(URLEncoder.encode(string, request.getCharset()));
}
else
{
builder.append(string);
}
count++;
}
}
return builder.toString();
}
/**
* 出錯時執行
*
* @param code
* @param stream
* @throws IOException
*/
public abstract void onError(int code, InputStream stream)
throws IOException;
/**
* 成功時執行
*
* @param code
* @param stream
* @throws IOException
*/
public abstract void onSuccess(int code, InputStream stream)
throws IOException;
}為了方便測試，簡單的編寫一個Servlet，程式碼如下：
package com.jhq.wx.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet
{
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
System.out.println(request.getParameter("p1"));
System.out.println(request.getParameter("p2"));
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
request.setCharacterEncoding("UTF-8");
System.out.println(request.getParameter("p1"));
System.out.println(request.getParameter("p2"));
}
}最後編寫一個測試類，測試模擬表單提交
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Test
{
public static void main(String[] args)
{
HttpRequest request = new HttpRequest("http://127.0.0.1/wx/s");
request.addParam("p1", "123");
request.addParam("p2", "蔣固金");
request.setMethod(RequestMethod.POST);
HttpClient client = new HttpClient()
{
@Override
public void onSuccess(int code, InputStream stream) throws IOException
{
// 內容是文字，直接以緩衝字元流讀取
BufferedReader reader = new BufferedReader(new InputStreamReader(
stream, "UTF-8"));
String data = null;
while ((data = reader.readLine()) != null)
{
System.out.print(data);
}
reader.close();
}
@Override
public void onError(int code, InputStream stream)
{
System.out.println("請求出現異常");
}
};
try
{
client.execute(request);
}
catch (IOException e)
{
e.printStackTrace();
}
}
}執行之後，我們可以看到服務端後臺輸出：
123
蔣固金
這樣就完成了Java模擬表單提交的操作。