httphelper2.java

采用JAVA开发

/*
 * Created on 2004-8-10
 *
 * To change the template for this generated file go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
package com.gctech.misc.util;

import java.util.*;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
//import javax.microedition.io.Connector;
//import javax.microedition.io.HttpConnection;
import java.net.*;
public class HttpHelper2 {
	private static final int MAX_REDIRECTS = 5;
	private static final int MAX_READ_SIZE = 20000; //允许从server端读取20000个
	public HttpHelper2() {
	}
	private String getResponse(InputStream in) {
		try {
			byte[] buf = new byte[MAX_READ_SIZE];
			int total = 0;
			while (total < MAX_READ_SIZE) {
				int count = in.read(buf, total, MAX_READ_SIZE - total);
				if (count < 0) {
					break;
				}
				total += count;
			}

			return new String(buf, 0, total);

		} catch (Exception ex) {
			throw new IllegalStateException(ex.getMessage());
		}

	}

	private Hashtable toMap(String response) {
		int start = 0;
		int end = 0;
		String line = null;
		int lineIndex = 0;
		String key = null;
		String value = null;
		Hashtable t = new Hashtable();
		while ((end = response.indexOf("\r\n", start)) != -1) {
			line = response.substring(start, end);
			start = end + 2;
			if (start > response.length())
				break;
			lineIndex = line.indexOf("=", 0);
			key = line.substring(0, lineIndex);
			value = line.substring(lineIndex + 1);
			t.put(key, value);
		}
		return t;
	}

	private String makeQuery(Hashtable map) {
		StringBuffer sb = new StringBuffer();
		for (Enumeration e = map.keys(); e.hasMoreElements();) {
			String key = e.nextElement().toString();
			sb.append(key).append("=").append(map.get(key).toString()).append("&");
		}
		sb.setLength(sb.length() - 1);
		//sb.append("\r\n"); 是否需要增加
		return sb.toString(); //must encode;
	}

	public Hashtable postMapResponse(String url, Hashtable parameters) {
		return toMap(postStringResponse(url, parameters));
	}

	public String postStringResponse(String url, Hashtable parameters) {
		InputStream is = null;
		OutputStream os = null;
		HttpURLConnection conn = null;
		int redirects = 0;
		try {

			String query = makeQuery(parameters); //"index=books&field-keywords=" + isbn + "\r\n" ;
			String requestMethod = "POST";

			while (redirects < MAX_REDIRECTS) {
				System.out.println("ready connect");

				conn = (HttpURLConnection) new URL(url).openConnection();
				conn.setDoInput(true);
				conn.setDoOutput(true);
				conn.setRequestMethod(requestMethod);

				System.out.println("connect ok");

				conn.setRequestMethod(requestMethod);
				conn.setRequestProperty("Connection", "Close");
				if (requestMethod.equals(requestMethod)) {
					conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
					os = conn.getOutputStream();
					os.write(query.getBytes());
					os.close();
					os = null;
				}

				// Read the response from the server
				is = conn.getInputStream();
				int code = conn.getResponseCode();

				// If we get a redirect, try again at the new location
				if ((code >= HttpURLConnection.HTTP_MOVED_PERM && code <= HttpURLConnection.HTTP_SEE_OTHER)
					|| code == HttpURLConnection.HTTP_MOVED_TEMP) //??
					{
					// Get the URL of the new location (always absolute)
					url = conn.getHeaderField("Location");
					is.close();
					conn.disconnect();
					is = null;
					conn = null;

					if (++redirects > MAX_REDIRECTS) {
						// Too many redirects - give up.

						break;
					}

					// Choose the appropriate request method
					requestMethod = "POST";
					if (code == HttpURLConnection.HTTP_MOVED_TEMP || code == HttpURLConnection.HTTP_SEE_OTHER) {
						requestMethod = "GET";
					}
					continue;
				}
				//		  String type = conn.getType () ;
				String type = "text/html";
				System.out.println("response type " + type);
				if (code == HttpURLConnection.HTTP_OK && type.indexOf("text/html") != -1) {
					System.out.println("retrive date from connection");
					return this.getResponse(is);
				} else {
					throw new IllegalStateException("response error");
				}
			}

			throw new IllegalStateException("can not find the url");
		} catch (Throwable t) {
			System.out.println(t);
			throw new IllegalStateException(t.getMessage());
		} finally {
			if (is != null) {
				try {
					is.close();
				} catch (IOException ex) {
				}
			}
			if (os != null) {
				try {
					os.close();
				} catch (IOException ex) {
				}
			}
			if (conn != null) {
				try {
					conn.disconnect();
				} catch (Exception ex) {
				}
			}
		}

	}

	public static void main(String[] args) {
		HttpHelper2 h = new HttpHelper2();
		Hashtable t = new Hashtable();
		String url = "http://localhost:8083/test/foxservlet";
		t.put("tid", "78");
		System.out.println(h.postStringResponse(url, t));
	}

}