JSP basic syntax

js| syntax

One, JSP elements

1, script elements, including expressions, code fragments (including built-in classes), declarations (member variables and methods), annotations (output and shadowing)
2, the instruction element, including page (Language,extends,import,session,buffer,autoflush,isthreadsafe,info,errorpage,iserrorpage, ContentType), include (file), and Taglib (Uri,prefix).
3, action elements, system elements:
Jsp:include page=? Flush= "true" (jsp1.1 must be This) can be entrained jsp:param to add request
Jsp:forward page=? Can be jsp:param to add request
Jsp:param name=? Value=?
Jsp:plugin
Type= "Bean|applet"
Code= "Classfilename"
Codebase= "Classfilepathurl"
Align=?height=?  Name=? Width=?hspace= "The size of the horizontal white space between the wrapping text" Vspace=?
Archive= "Identifies the URL of the. jar file for the Java class containing the object"
Jrevision= "identifies the runtime environment JRE version required by the component, default 1.1"
Title= "object title used by IE"
Nspluginurl= "The URL of the JRE plugin can be downloaded for Netscape"
Iepluginurl= "The URL of the JRE plugin can be downloaded for IE"
Jsp:params by Jsp:plugin encapsulated a jsp:action list like Jsp:param placed in the middle
Jsp:fallback load Jsp:plugin is used to provide an alternate HTML response, such as a piece of text
Jsp:usebean
Id= "Instance Name"
Scope= "Page|request|session|application"
Class= "class name, if there is no type must have class, if there is beanname must not class"
Beanname= "a.b.c|a/b/c.cer, not incompatibility with class"
Type= "has the class name of the interface, or the name of the interface implemented by the class (can only use methods in the interface)"
Jsp:setproperty name= "Bean instance ID" property= "bean must have Setpropertyname () method" [param=?] value=? If you do not specify value, take a variable from request with the same name or param name, if the value is "" does not execute
Jsp:getproperty name= "Bean id" property= "Bean property, must have Getpropertyname () method" The action element directly outputs
4, white space character: space (0x20), Tab (0x09), carriage return (0x0d0a), these symbols in the JSP page will be out.println
5, escape character%>,,%>, ', ' should all use \ Escape


two, hidden objects

1,request javax.servlet.HttpServletRequest Type,
String GetParameter (string parametername);
Java.util.Enumeration Getparamerternames ();
String[] Getparametervalues ();

Object getattribute (String name);
Java.util.Enumeration Getattributenames ();
void RemoveAttribute (String attributename);
void SetAttribute (String name, object);

Javax.servlet.http.cookie[] GetCookies ();

Java.util.Enumeration getheadernames ()/message header
Java.util.Enumeration getheaders (String headername);
String GetHeader (string headername);
int Getintheader (String headername);
Long Getdateheader (String headername);

String GetMethod ();//Request method
String getrequesturi;//between the protocol name and the query string, no host name
String Getcontextpath ()//The application environment in which the requested file resides
String Getservletpath ();//ContextPath as root, specifying where the applet or JSP resides
String pathinfo ()//additional path information
String getquerystring ();

Boolean issecure ()//whether HTTPS is used
Boolean Isrequestedsessionidfromcookie ();
Boolean Isrequestedsessionidfromurl ();
Boolean isrequestedsessionidvalid ()//The ID of the request session is valid

Java.util.Locale GetLocale ()//The customer agrees that the content taken by the Locale depends on the Acceptlanguge
Java.util.Enumeration Getlocales ();
2,response Javax.servlet.http.HttpServletResponse
int getbuffersize ();
void setbuffersize (int size);//
Boolean iscommitted ()//The response has been committed after writing the status code and header
void reset ()//purge all data in the cache including status codes and headers
void Flushbuffer ();//force any content in the cache to be written to customer

void AddHeader (String name,string value);
void SetHeader (string name, string value);
void Adddateheader (String name, long date);
void Setdateheader (String name, long date);
void Addintheader (String name, int value);
void Setintheader (String name, int value);
Boolean Containsheader (String name);
void setContentType (String type);
void SetLocale (Java.uti.Locale, Locale);

void Senderror (int sc, String msg);
void Senderror (int sc);//Status code and descriptive information item the customer sends an error response
void Sendredirect (String location);
3,pagecontext Javax.servlet.jsp.PageContext (materialized by specific developers)
/*int Scope:
Pagecontext.page_scope
Pagecontext.request_scope
Pagecontext.session_scope
Pagecontext.application_scope
*/
Object getattribute (String name);//pagescope variable
Object getattribute (String name, int scope);
Object Findattribute (String name);
Java.util.Enumeration getattributenamesinscope (int scope);
int Getattributescope (String name);
void RemoveAttribute (String name);
void RemoveAttribute (String name, int scope);
void SetAttribute (String name, object);
void SetAttribute (String name, object object, int scope);

Javax.servlet.jsp.JspWriter getout ();//out
Exception getexception ();//exception
Javax.servlet.ServletRequest getrequest ();//request
Javax.servlet.ServletResponse GetResponse ();//response
Javax.servlet.http.HttpSession getsession ();//session
Javax.servlet.ServletConfig getservletconfig ();//config
Javax.servlet.ServletContext Getservletcontext ();//application

Javax.servlet.jsp.JspWriter Popbody ();
Javax.servlet.jsp.tagext.BodyContent pushbody ();//manage nested output streams within taglib

void forward (String relativeurlpath);
void include (String relativeurlpath);
void HandleException (Java.lang.Exception e);

4,session javax.servlet.http.HttpSession
Install cookies

URL Rewrite

SSL session

Object getattribute (String attributename);
Java.util.Enumeration Getattributenames ();
void SetAttribute (String name, Object value);
void RemoveAttribute (String name);

Long Getlastaccessedtime ()//time of last send related data for this session
/* About long time: refers to the number of milliseconds starting from 1970-1-1 00:00:00 * *
void setmaxinactiveinterval (int interval);//sec
int Getmaxinactiveinterval ();
void invalidate ();//Make session invalid

5,out Javax.servlet.jsp.JspWriter
Errors can cause java.io.IOException
void clear ();//purge buffer, Response.reset ()?
void Clearbuffer ();//Clear Buffer Current Contents
void Flush ();//
void Close ()//refresh before closing
int getbuffersize ();
int getremaining ()//Buffer not used
Boolean Isautoflush ();//page AutoFlush Property

void print (object);
void println (Object object);
6,application Javax.servlet.ServletContext
String Getinitparameter (string name);
Java.util.Enumeration Getinitparameternames ();

Object getattribute (String name);
void Setattibute (String name, object);
Java.util.Enumeration Getattributenames ();
void RemoveAttribute (String name);
When modified, the IsThreadSafe is best set to false, and with synchronized ()

Java.net.URL getresource (String path);
Url::getpath () is the same as Application.getrealpath ()
Java.io.InputStream getResourceAsStream (String path);/with Url:http://www.alixixi.com/program/a/:openstream ();

RequestDispatcher: Work in service between the server Laughing program
Javax.servlet.RequestDispatcher Getnameddispatcher (String name);//name is the name of the servlet
Javax.servlet.RequestDispatcher getrequestdispatcher (String path);//path as the path to the servlet

void log (String message);
void log (String message, throwable throwable);//Log a messages and stack trace to a small program log file
String GetMimeType (string file);
String Getrealpath (string virtualpath);//url::getpath
String Getserverinfo ();
int getmajorvertion ();
int getminervertion ();

7,config Javax.servlet.ServletConfig
String Getinitparameter (string name);
Java.util.Enumeration Getinitparameternames ();
String Getservletname ();
ServletContext Getservletcontext ();
8,page Javax.servlet.jsp.HttpJspPage
is not usually used by the creator of the JSP page
Javax.servlet.ServletConfig Getservletconfig ();
String Getserveletinfo ();
9,exception java.lang.Exception
String Getlocalizedmessage ();
String GetMessage ();
void Printstacktrace ();
void Printstacktrace (Java.io.PrintStream PS);
void Printstacktrace (Java.io.PrintWriter pw);