How to better use the Jtextpane

I often see many friends on the Internet asking how to control characters in JTextArea, how to set the color of a particular character, and so on. I am in Java to do a SQL Query Analyzer found a better solution is to use Jtextpane, then how to better use Jtextpane, I now pick part of the program part of the process for your reference.

package com. Jdagui;


import javax.swing.text.*;


import java.util.*;


import java.awt.*;


import com. jda.*;


/**


* @author Whxu


*/


public class Jdastyleddocument extends Defaultstyleddocument


{


private int type = -1;//data connection type


AttributeSet myattributeset = null;


public jdastyleddocument (int type)


　 {


this.type = type;


　 }


　 /**


* Insert String


　 */


public void insertstring (int offset,string str,attributeset a)


throws Badlocationexception


　 {


this.myattributeset = A;


Super.insertstring (Offset,str,a);


Setsyntaxcolor (Offset,str.length ());


　 }


/**


* Delete String


　 */


public void Remove (int offs,int len)


throws Badlocationexception


　 {


Super.remove (Offs,len);


Setsyntaxcolor (offs);


　 }


　 /**


* Get the character of the position


　 */


private String Getpositionchar (int offset)


　 {


String str = "";


Try


　　 {


str = getText (offset,1);


　　 }


catch (Badlocationexception ex)


　　 {


//ex.printstacktrace (System.out);


　　 }


return str;


　 }


/**


* Starts at the specified position, pushing backwards to the first encountered space position


　 */


Private String getbeforeblankstring (int offset)


　 {


String str = "";


if (offset<0) return "";


　


str = Getpositionchar (offset);


if (Syntaxmgr.isspacechar (str))


return "";


String r = getbeforeblankstring (offset-1);


return r + str;


　 }


　 /**


* Starts at the specified position and pushes to the first space position encountered


　 */


private String getafterblankstring (int offset)


　 {


String str = "";


if (Offset>getlength ()) return "";


str = Getpositionchar (offset);


if (Syntaxmgr.isspacechar (str))


return "";


String r = getafterblankstring (offset+1);


return str + R;


　 }


　 /**


* According to Postion, forward judgment, backward judgement, set color, return to set the position of the end of the color


　 */


private int Setsyntaxcolor (int offset)


　 {


if (offset<0) return offset;//If the location you set does not exist, you may not have to consider


if (myattributeset==null) return offset;//if Myattributeset is null, you do not have to consider


String ifsyntax = "";


String before = getbeforeblankstring (offset-1);


String after = getafterblankstring (offset);


Syntax = (before + after). Trim ();


int start = Offset-before.length ();


int tmp_len = Ifsyntax.length ();


if (start<0 | | tmp_len<=0) return offset;//if the string that sets the color is empty, returns the


//Set color


Styleconstants.setforeground (MutableAttributeSet) Myattributeset,


Syntaxmgr.issyntax (Type,ifsyntax));


setcharacterattributes (start,tmp_len,myattributeset,true);


return start + Tmp_len;


　 }


　 /**


* According to a range, set within the range of the Syntaxcolor


　 */


private int Setsyntaxcolor (int offset,int len)


throws Badlocationexception


　　 {


//If scope does not exist, do not consider


if (offset<0 | | | len<0) return offset;


int tmp_offset = offset;


while (Tmp_offset<offset + len)


　　　 {


Tmp_offset = Setsyntaxcolor (Tmp_offset);


Tmp_offset = Getnextwordoffset (Tmp_offset);


　　　 }


Tmp_offset = Setsyntaxcolor (Tmp_offset);/Set the Last word after the loop is finished


return tmp_offset;


　　 }


　　 /**


* According to Postion, get the starting point of the next word


　　 */


private int getnextwordoffset (int offset)


　　 {


int roffset = offset;


int textlength = GetLength ();


while (roffset<=textlength && offset>=0)


　　　 {


String str = Getpositionchar (roffset);


if (! Syntaxmgr.isspacechar (str))


　　　　 {


break;


　　　　 }


roffset+=1;


　　　 }


if (roffset!=offset)//sets the color of the interval


　　 {


//Set color


Styleconstants.setforeground (MutableAttributeSet) Myattributeset,


Syntaxcolormgr.getspacecolor ());


setcharacterattributes (offset,roffset-offset,myattributeset,true);


　　 }


return roffset;


　 }


}

To this end, we have done a document that applies to Jtextpane. The use of Jtextpane is relatively simple.

Can be used in this way

Jtextpane Sqlpane = new Jtextpane (new Jdastyleddocument (type));

Because I used this example to display different keywords depending on the database type, I passed an int type.