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用来访问HTTP服务器的仿java.net功能类

一个用来访问http服务器的东西。功能类似于java.net中的那个,但这个对Post方法的支持更好。

作者:佚名来源:百家编程|2009-06-06 19:02

开发者大赛路演 | 12月16日,技术创新,北京不见不散


下面这段代码用来访问HTTP服务器,比Java.net中对Post方法的支持的更好。

package net.sonyhome.net;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
public class HttpConnection {
private URL url = null;
//private boolean doInput = true;
//private boolean doOutput = true;

private boolean usePost = false;

private boolean useCaches = false;

private Vector reqHeaderNames = new Vector();
private Vector reqHeaderValues = new Vector();
private Vector resHeaderNames = null;
private Vector resHeaderValues = null;
private Socket socket = null;
private OutputStream out = null;
private InputStream in = null;
private boolean useHttp11 = false;

private boolean connected = false;

private boolean inputStarted = false;

Hashtable postData = new Hashtable();
Hashtable getData = new Hashtable();

/**
* HttpConnection constructor comment.
*/
public HttpConnection(URL url) {
super();
this.url = url;
}
/**
* Insert the method@#s description here.
* @param name java.lang.String
* @param value java.lang.String
*/
public void addGet(String name, String value) {
getData.put(name, value);
}
/**
* Insert the method@#s description here.
* @param name java.lang.String
* @param value java.lang.String
*/
public void addPost(String name, String value) {
postData.put(name, value);
}
public void close() throws IOException {
if (!connected)
return;
out.close();
if (inputStarted)
in.close();
socket.close();
}
public void connect() throws IOException {
if (connected)
return;
if (!useCaches) {
setRequestProperty("Pragma", "no-cache");
//setRequestProperty("Cache-Control", "no-cache, must-revalidate");
//setRequestProperty("Expires", "Mon, 26 Jul 1997 05:00:00 GMT");
}
String protocol = url.getProtocol();
if (!protocol.equals("http"))
throw new UnknownServiceException("unknown protocol");
String host = url.getHost();
int port = url.getPort();
if (port == -1)
port = 80;
String file = url.getFile();

socket = new Socket(host, port);
out = socket.getOutputStream();
PrintStream pout = new PrintStream(out);

String method;
if (usePost) {
method = "POST";
setRequestProperty("Content-type", "application/x-www-form-urlencoded");
int len = getPostDataLength();
setRequestProperty("Content-length", String.valueOf(getPostDataLength()));

}
else
method = "GET";
if (getGetDataLength() > 0) {
file += "?" + getGetDataString();
}
pout.println(method + " " + file + " HTTP/1.0");

for (int i = 0; i < reqHeaderNames.size(); ++i) {
String name = (String) reqHeaderNames.elementAt(i);
String value = (String) reqHeaderValues.elementAt(i);
pout.println(name + ": " + value);
}
pout.println("");
if (usePost) {
String ttt = getPostDataString();
pout.println(getPostDataString());
}

pout.flush();

connected = true;
}
/**
* Insert the method@#s description here.
* @return boolean
* @exception java.lang.IllegalStateException The exception description.
*/
public boolean contentIsText() throws IOException {
String type = getContentType();
if (type.startsWith("text"))
return true;
return false;
}
/**
* Insert the method@#s description here.
* @return byte[]
*/
public byte[] getByteArray() throws IOException {
DataInputStream din = new DataInputStream(getInputStream());

byte[] ret;
byte[] b = new byte[1024];
int off = 0, len = 0;

ByteArrayOutputStream bos = new ByteArrayOutputStream();
while ((len = din.read(b, off, 1024)) > 0) {
bos.write(b, 0, len);
if (len < 1024)
break;
}
bos.flush();
bos.close();
return bos.toByteArray();
}
// Gets the content length.  Returns -1 if not known.
public int getContentLength() throws IOException {
return getHeaderFieldInt("content-length", -1);
}
/// Gets the content type.  Returns null if not known.
public String getContentType() throws IOException {
return getHeaderField("content-type");
}
/**
* Insert the method@#s description here.
* @return java.lang.String
*/
public int getGetDataLength() {
return getGetDataString().length();
}
/**
* Insert the method@#s description here.
* @return java.lang.String
*/
public String getGetDataString() {
StringBuffer buf = new StringBuffer();
Enumeration enu = getData.keys();
while (enu.hasMoreElements()) {
String key = (String) (enu.nextElement());
String value = (String) (getData.get(key));
if (buf.length() > 0)
buf.append("&");
buf.append(key);
buf.append("=");
buf.append(URLEncoder.encode(value));
}
return buf.toString();
}
public String getHeaderField(String name) throws IOException {
if (resHeaderNames == null)
startInput();
int i = resHeaderNames.indexOf(name.toLowerCase());
if (i == -1)
return null;
return (String) resHeaderValues.elementAt(i);
}
public long getHeaderFieldDate(String name, long def) throws IOException {
try {
return DateFormat.getDateInstance().parse(getHeaderField(name)).getTime();
}
catch (ParseException e) {
throw new IOException(e.toString());
}
}
public int getHeaderFieldInt(String name, int def) throws IOException {
try {
return Integer.parseInt(getHeaderField(name));
}
catch (NumberFormatException t) {
return def;
}
}
/**
* Insert the method@#s description here.
* @return java.util.Enumeration
*/
public Enumeration getHeaderNames() {
return resHeaderNames.elements();
}
public InputStream getInputStream() throws IOException {
startInput();
return in;
}
public OutputStream getOutputStream() throws IOException {
connect();
return out;
}
/**
* Insert the method@#s description here.
* @return java.lang.String
*/
public int getPostDataLength() {
return getPostDataString().length();
}
/**
* Insert the method@#s description here.
* @return java.lang.String
*/
public String getPostDataString() {
StringBuffer buf = new StringBuffer();
Enumeration enu = postData.keys();
while (enu.hasMoreElements()) {
String key = (String) (enu.nextElement());
String value = (String) (postData.get(key));
if (buf.length() > 0)
buf.append("&");
buf.append(key);
buf.append("=");
buf.append(URLEncoder.encode(value));
}
return buf.toString();
}
public String getRequestProperty(String name) {
if (connected)
throw new IllegalAccessError("already connected");
int i = reqHeaderNames.indexOf(name);
if (i == -1)
return null;
return (String) reqHeaderValues.elementAt(i);
}
public URL getURL() {
return url;
}
public boolean getUseCaches() {
return useCaches;
}
public boolean getUseHttp11() {
return useHttp11;
}
/**
* Insert the method@#s description here.
* @return boolean
*/
public boolean isUsePost() {
return usePost;
}
/**
* Insert the method@#s description here.
* @param args java.lang.String[]
*/
public static void main(String[] args) {
try {
/*
URL url=new URL("http","192.168.0.3","/Post.php");
HttpConnection con=new HttpConnection(url);
con.setUsePost(true);
con.setUseCaches(false);
//con.setRequestProperty("Connection", "Keep-Alive");

con.addGet("TextField","你好");
con.addGet("Submit", "submit");

con.connect();
//ByteArrayOutputStream bos=con.getByteArray();
byte[] ret=con.getByteArray();
System.out.println(new String(ret));

System.out.println("");
Enumeration enu=con.getHeaderNames();
while (enu.hasMoreElements()) {
String headerName=(String)(enu.nextElement());
System.out.println(headerName+": "+con.getHeaderField(headerName));
}
con.close();
*/

URL url = new URL("http", "192.168.0.3", "/codemaker/IMAGES/BO.GIF");
HttpConnection con = new HttpConnection(url);
con.connect();

FileOutputStream fos = new FileOutputStream("d:\\bo.gif");
fos.write(con.getByteArray());
fos.flush();
fos.close();

System.out.println("");
Enumeration enu = con.getHeaderNames();
while (enu.hasMoreElements()) {
String headerName = (String) (enu.nextElement());
System.out.println(headerName + ": " + con.getHeaderField(headerName));
}
con.close();

}
catch (Exception e) {
e.printStackTrace();
}
}
/**
* Insert the method@#s description here.
* @param name java.lang.String
* @param value java.lang.String
*/
public void removeGet(String name) {
getData.remove(name);
}
/**
* Insert the method@#s description here.
* @param name java.lang.String
* @param value java.lang.String
*/
public void removePost(String name) {
postData.remove(name);
}
public void setRequestProperty(String name, String value) {
if (connected)
throw new IllegalAccessError("already connected");
reqHeaderNames.addElement(name);
reqHeaderValues.addElement(value);
}
public void setUseCaches(boolean useCaches) {
if (connected)
throw new IllegalAccessError("already connected");
this.useCaches = useCaches;
}
public void setUseHttp11(boolean useHttp11) {
if (connected)
throw new IllegalAccessError("already connected");
this.useHttp11 = useHttp11;
}
/**
* Insert the method@#s description here.
* @param newUsePost boolean
*/
public void setUsePost(boolean newUsePost) {
if (connected)
throw new IllegalAccessError("already connected");
usePost = newUsePost;
}
private void startInput() throws IOException {
connect();
if (inputStarted)
return;
in = socket.getInputStream();
resHeaderNames = new Vector();
resHeaderValues = new Vector();
DataInputStream din = new DataInputStream(in);
String line;

// Read and ignore the status line.
line = din.readLine();
// Read and save the header lines.
while (true) {
line = din.readLine();
if (line == null || line.length() == 0)
break;
int colonBlank = line.indexOf(": ");
if (colonBlank != -1) {
String name = line.substring(0, colonBlank);
String value = line.substring(colonBlank + 2);
resHeaderNames.addElement(name.toLowerCase());
resHeaderValues.addElement(value);
}
}

inputStarted = true;
}
/**
* Returns a String that represents the value of this object.
* @return a string representation of the receiver
*/
public String toString() {
// Insert code to print the receiver here.
// This implementation forwards the message to super. You may replace or supplement this.
return this.getClass().getName() + ":" + url;
}
}

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