ASCII 格式的DXF文件可以用java利用组码实现，每个部分可进行封装。组码的书写需要注意空格，每行组码结束不能有空格，不然无法解析
1.header实现，getBoundX getBoundY是定义当前画布的左上角XY坐标，getBoundWidth(),getBoundHeight()是画布长宽
private void writeHeader ()
throws IOException
{
writeBufferLine ( " 0" ) ;
writeBufferLine ( "SECTION" ) ;
writeBufferLine ( " 2" ) ;
writeBufferLine ( "HEADER" ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$EXTMIN" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( getBoundX () ).toString () ) ;
writeBufferLine ( "20" ) ;
writeBufferLine ( new Double ( getBoundY () ).toString () ) ;
writeBufferLine ( "30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$EXTMAX" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertXToPaper ( getBoundX () + getBoundWidth () ) ).
toString () ) ;
writeBufferLine ( "20" ) ;
writeBufferLine ( new Double ( convertYToPaper ( getBoundY () + getBoundHeight () ) ).
toString () ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$LIMMIN" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertXToPaper ( getBoundX () ) ).toString () ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double ( convertYToPaper ( getBoundY () ) ).toString () ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$LIMMAX" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertXToPaper ( getBoundX () + getBoundWidth () ) ).
toString () ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double ( convertYToPaper ( getBoundY () + getBoundHeight () ) ).
toString () ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$PEXTMIN" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertXToPaper ( getBoundX () ) ).toString () ) ;
writeBufferLine ( "20" ) ;
writeBufferLine ( new Double ( convertYToPaper ( getBoundY () ) ).toString () ) ;
writeBufferLine ( "30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 9" ) ;
writeBufferLine ( "$PEXTMAX" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertXToPaper ( getBoundX () + getBoundWidth () ) ).
toString () ) ;
writeBufferLine ( "20" ) ;
writeBufferLine ( new Double ( convertYToPaper( getBoundY () + getBoundHeight () ) ).
toString () ) ;
writeBufferLine ( "30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 0" ) ;
writeBufferLine ( "ENDSEC" ) ;
}
2.定义图层和类型
private void writeTables ()
throws IOException
{
writeBufferLine ( " 0" ) ;
writeBufferLine ( "SECTION" ) ;
writeBufferLine ( " 2" ) ;
writeBufferLine ( "TABLES" ) ;
writeTableLAYER () ;
writeTableLTYPE () ;
writeBufferLine ( " 0" ) ;
writeBufferLine ( "ENDSEC" ) ;
}
3.具体的资源
资源一般是点，线，多条线，面，面资源也是无数条线组成，所以就点、线结构
可对写点，写线，和点线的标注进行封装，写入资源的方式很重要，1种是直接写入ENTITIES中，
这种写法当用mapinfo转成tab格式时，每个图层可用表展现，但是表里不会带入点、线的属性。
a:写线
private void writePolylineAD ( Point2D[] _pts , int _color ,
String _lineStyle , String _layerName )
throws IOException
{
if ( _pts.length > 2 )
{
for ( int i = 0 ; i <= _pts.length - 1 ; i++ )
{
if ( i < _pts.length - 1 )
{
Point2D[] pts = new Point2D.Double[2 ] ;
pts[ 0 ] = _pts[ i ] ;
pts[ 1 ] = _pts[ i + 1 ] ;
writePolylineAD ( pts , _color , _lineStyle , _layerName ) ;
}
}
return ;
}
writeBufferLine ( " 0" ) ;
writeBufferLine ( "POLYLINE" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( _layerName ) ;
writeBufferLine ( " 62" ) ;
writeBufferLine ( new Integer ( _color ).toString () ) ;
writeBufferLine ( " 6" ) ;
writeBufferLine ( _lineStyle ) ;
writeBufferLine ( " 66" ) ;
writeBufferLine ( " 1" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
for ( int j = 0 ; j < _pts.length ; j++ )
{
writeBufferLine ( " 0" ) ;
writeBufferLine ( "VERTEX" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( _layerName ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( _pts[ j ].getX () ).toString () ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double ( _pts[ j ].getY () ).toString () ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
}
writeBufferLine ( " 0" ) ;
writeBufferLine ( "SEQEND" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( _layerName ) ;
}
b:写标注
private void writeText ( double _x , double _y , double _fontSize ,
int _color , String _text , int Align ,
String _layerName , double _angle,double xOffset,double yOffset )
throws IOException
{
if(_text.contains("<br>"))
{
ArrayList<String> textA=splitBR(_text);
for(int j=0;j<textA.size();j++)
{
double tY;
tY=_y-j*_fontSize;
writeText(_x,tY,_fontSize,_color,textA.get(j).toString(),Align,_layerName,_angle,xOffset,yOffset);
}
}else
{
Rectangle2D rect = new Rectangle2D.Double ( getBoundX () , getBoundY () ,
getBoundWidth () , getBoundHeight () ) ;
int out = rect.outcode ( _x , _y ) ;
if ( out != 0 )
{
return ;
}
if ( _text == null || _text.equals ( "" ) )
return ;
writeBufferLine ( " 0" ) ;
writeBufferLine ( "TEXT" ) ;
writeBufferLine ( " 8" ) ;
// if ( m_bLabelMerge )
// writeBufferLine ( "label" ) ;
// else
writeBufferLine ( _layerName ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double ( convertX ( _x ) +xOffset).toString () ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double ( convertY ( _y )+yOffset ).toString () ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 11" ) ;
writeBufferLine ( new Double ( convertX ( _x ) +xOffset).toString () ) ;
writeBufferLine ( " 21" ) ;
writeBufferLine ( new Double ( convertY ( _y )+yOffset ).toString () ) ;
writeBufferLine ( " 31" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 40" ) ;
writeBufferLine ( new Double ( _fontSize ).toString () ) ;
writeBufferLine ( " 41" ) ;
writeBufferLine ( "0.78" ) ;
writeBufferLine ( " 50" ) ;
writeBufferLine ( new Double ( _angle ).toString () ) ;
if ( false )
{
//文字颜色,暂时不实现
writeBufferLine ( " 62" ) ;
writeBufferLine ( new Integer ( _color ).toString () ) ;
}
writeBufferLine ( " 1" ) ;
//去掉换行符，该版本不支持
_text = _text.replace ( "\r" , "" ) ;
_text = _text.replace ( "\n" , "" ) ;
writeBufferLine ( _text ) ;
writeBufferLine ( " 72" ) ;
writeBufferLine ( new Integer ( Align ).toString () ) ;
writeBufferLine ( " 73" ) ;
writeBufferLine ( "3" ) ;
}
}
第二种是把点线以BLOCKS包装，属于带属性的导出。
点属性导出
private void writeGisPointSingleAtt(IMapVertex v,String layerName,int blockNum,int objNum)
throws IOException
{
writeBufferLine ( " 0" ) ;
writeBufferLine ( "BLOCK" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( layerName ) ;
writeBufferLine ( " 2" ) ;
//组码 block 名称
writeBufferLine ( "BLKP"+String.valueOf(blockNum)+"p"+String.valueOf(objNum) ) ;
writeBufferLine ( " 70" ) ;
writeBufferLine ( " 2" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 0" ) ;
writeBufferLine ( "POINT" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( layerName ) ;
writeBufferLine ( " 62" ) ;
writeBufferLine ( " 1" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double(v.getX()).toString() ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double(v.getY()).toString() ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
ArrayList<String> attr=new ArrayList<String>();
attr.add("Name");
attr.add("Longitude");
attr.add("Latitude");
attr.add("Planid");
attr.add("IsVirtual");
attr.add("Isabpoint");
attr.add("Iskeyres");
attr.add("Cutpoints");
writeAttrInVertex(attr,layerName);
writeBufferLine ( " 0" ) ;
writeBufferLine ( "ENDBLK" ) ;
}
//每个点带属性导出至DXF,便于mapinfo的转换
//20121221
private void writeGisPointWithAtt(ArrayList<IMapVertex> res,ArrayList<String> layerNameRes)
throws IOException
{
for(int i=0;i<res.size();i++)
{
YVertexReduce v=(YVertexReduce)res.get(i).getID();
writeBufferLine ( " 0" ) ;
writeBufferLine ( "BLOCK" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( layerNameRes.get(i) ) ;
writeBufferLine ( " 2" ) ;
//组码 block 名称
writeBufferLine ( "BLK"+String.valueOf(i) ) ;
writeBufferLine ( " 70" ) ;
writeBufferLine ( " 2" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
writeBufferLine ( " 0" ) ;
writeBufferLine ( "POINT" ) ;
writeBufferLine ( " 8" ) ;
writeBufferLine ( layerNameRes.get(i) ) ;
writeBufferLine ( " 62" ) ;
writeBufferLine ( " 1" ) ;
writeBufferLine ( " 10" ) ;
writeBufferLine ( new Double(v.geoX).toString() ) ;
writeBufferLine ( " 20" ) ;
writeBufferLine ( new Double(v.geoY).toString() ) ;
writeBufferLine ( " 30" ) ;
writeBufferLine ( "0.0" ) ;
ArrayList<String> attr=new ArrayList<String>();
attr.add("Name");
attr.add("Longitude");
attr.add("Latitude");
attr.add("Planid");
attr.add("IsVirtual");
attr.add("Isabpoint");
attr.add("Iskeyres");
attr.add("Cutpoints");
writeAttrInVertex(attr,layerNameRes.get(i));
writeBufferLine ( " 0" ) ;
writeBufferLine ( "ENDBLK" ) ;
}
}
4.结尾
private void writeTail ()
throws IOException
{
writeBufferLine ( " 0" ) ;
writeBufferLine ( "EOF" ) ;
}