JSP basic 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 be escaped

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::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);