使用JSP读取客户端信息

　 请阅读以下代码。如果你的使用要求不同，可对这些代码加以很方便的修改。这些代码可以使你获得：
公司company, 用户name，版本version，main version，minor version
操作系统(未完成!)，语言language，locale等。

建立一个新的JSP文件:




请将下列class文件加入classpath (你要建立同样的目录结构-- de.hunsicker.http.util，当然也可以自己调节包的名称。!):




package de.hunsicker.http.util;

import java.util.*;

import javax.servlet.*;
import javax.servlet.http.*;

public class Browser extends HttpServlet
{
protected HttpServletRequest request;
protected HttpSession session;

protected String userAgent;
protected String company; // Firmenname des Herstellers
protected String name; // Bezeichnung des Browsers
protected String version; // Version
protected String mainVersion; // Hauptversion
protected String minorVersion; // Unterversion
protected String os; // Betriebssystem
protected String language = "de"; // Sprachcode Standard
protected Locale locale; // Locale-Objekt mit den aktuellen
// Spracheinstellungen

private Hashtable supportedLanguages; // Untersttzte Sprachen

public Browser(HttpServletRequest request, HttpSession session)
{
this.initialize();
this.request = request;
this.session = session;

this.setUserAgent(this.request.getHeader("User-Agent"));
this.setCompany();
this.setName();
this.setVersion();
this.setMainVersion();
this.setMinorVersion();
this.setOs();
this.setLanguage();
this.setLocale();
}

public void initialize()
{
this.supportedLanguages = new Hashtable(2);

this.supportedLanguages.put("en", "");
this.supportedLanguages.put("de", "");
}

public void setUserAgent(String httpUserAgent)
{
this.userAgent = httpUserAgent.toLowerCase();
}

private void setCompany()
{
if (this.userAgent.indexOf("msie") > -1)
{
this.company = "Microsoft";
}
else if (this.userAgent.indexOf("opera") > -1)
{
this.company = "Opera Software";
}
else if (this.userAgent.indexOf("mozilla") > -1)
{
this.company = "Netscape Communications";
}
else
{
this.company = "unknown";
}
}

/**
* Liefert den Firmennamen des Herstellers des verwendeten Browsers.
*/
public String getCompany()
{
return this.company;
}

private void setName()
{
if (this.company == "Microsoft")
{
this.name = "Microsoft Internet Explorer";
}
else if (this.company == "Netscape Communications")
{
this.name = "Netscape Navigator";
}
else if (this.company == "Operasoftware")
{
this.name = "Operasoftware Opera";
}
else
{
this.name = "unknown";
}
}

/**
* Liefert den Namen des verwendeten Browsers.
*/
public String getName()
{
return this.name;
}

private void setVersion()
{
int tmpPos;
String tmpString;

if (this.company == "Microsoft")
{
String str = this.userAgent.substring(this.userAgent.indexOf("msie") + 5);
this.version = str.substring(0, str.indexOf(";"));
}
else
{
tmpString = (this.userAgent.substring(tmpPos = (this.userAgent.indexOf("/")) + 1, tmpPos + this.userAgent.indexOf(" "))).trim();
this.version = tmpString.substring(0, tmpString.indexOf(" "));
}
}

/**
* Liefert die Versionsnummer des verwendeten Browsers.
*/
public String getVersion()
{
return this.version;
}

private void setMainVersion()
{
this.mainVersion = this.version.substring(0, this.version.indexOf("."));
}

/**
* Liefert die Hauptversionsnummer des verwendeten Browsers.
*/
public String getMainVersion()
{
return this.mainVersion;
}

private void setMinorVersion()
{
this.minorVersion = this.version.substring(this.version.indexOf(".") + 1).trim();
}

/**
* Liefert die Unterversionsnummer des verwendeten Browsers.
*/
public String getMinorVersion()
{
return this.minorVersion;
}

private void setOs()
{
if (this.userAgent.indexOf("win") > -1)
{
if (this.userAgent.indexOf("windows 95") > -1 || this.userAgent.indexOf("win95") > -1)
{
this.os = "Windows 95";
}
if (this.userAgent.indexOf("windows 98") > -1 || this.userAgent.indexOf("win98") > -1)
{
this.os = "Windows 98";
}
if (this.userAgent.indexOf("windows nt") > -1 || this.userAgent.indexOf("winnt") > -1)
{
this.os = "Windows NT";
}
if (this.userAgent.indexOf("win16") > -1 || this.userAgent.indexOf("windows 3.") > -1)
{
this.os = "Windows 3.x";
}
}
}

/**
* Liefert den Namen des Betriebssystems.
*/
public String getOs()
{
return this.os;
}

private void setLanguage()
{
String prefLanguage = this.request.getHeader("Accept-Language");

if (prefLanguage != null)
{
String language = null;
StringTokenizer st = new StringTokenizer(prefLanguage, ",");

int elements = st.countTokens();

for (int idx = 0; idx elements; idx++)
{
if (this.supportedLanguages.containsKey((language = st.nextToken())))
{
this.language = this.parseLocale(language);
}
}
}
}

/*
* Hilfsfunktion fr setLanguage().
*/
private String parseLocale(String language)
{
StringTokenizer st = new StringTokenizer(language, "-");

if (st.countTokens() == 2)
{
return st.nextToken();
}
else
{
return language;
}
}

/**
* Liefert das L?nderkürzel der vom Benutzer
* bevorzugten Sprache.
*/
public String getLanguage()
{
return this.language;
}

private void setLocale()
{
this.locale = new Locale(this.language, "");
}

/**
* Liefert ein Locale-Objekt mit der Sprach-Prferenz des verwendeten Browsers
*/
public Locale getLocale()
{
return this.locale;
}
}