featuretest.java

MapXtreme 用于电子地图制作与分析

package barchant;

import java.util.*;
import com.mapinfo.dp.*;
import com.mapinfo.util.*;
import com.mapinfo.beans.vmapj.VisualMapJ;
import com.mapinfo.mapj.FeatureLayer;
import com.mapinfo.dp.util.RewindableFeatureSet;

/*该示例演示了有关图元的一些方法，成功*/

public class FeatureTest {
 public FeatureLayer world;//Feature对象用来访问地图对象
 public VisualMapJ myMap;//可管理地图集的各种状态，并向服务器转发客户请求

  public FeatureTest() {
  List columns = new ArrayList();
  Feature ftr;
  Geometry geom;
  DoubleRect rect;
  DoublePoint dblPnt;
  PointGeometry pntGeometry;
  VectorGeometry vectorGeometry;
  PointList pntList;
  Attribute attrib;
  int attribCount;

    try{
      //创建地图
      myMap=new VisualMapJ();
      myMap.getMapJ().loadMapDefinition("d:\\program files\\MapInfo\\MapXtreme-4.7.0\\examples\\server\\data\\local\\world.mdf");
      //mdf是地图定义文件
      world=(FeatureLayer)myMap.getMapJ().getLayers().get("World Countries");//得到World Countries图层

     // Get the Table information from the FeatureLayer
      TableInfo tabInfo = world.getTableInfo();
     // fill vector with Column names
    // System.out.println("tableColumnCount="+tabInfo.getColumnCount());
      for (int i=0;i<tabInfo.getColumnCount();i++)
      {
        columns.add(tabInfo.getColumnName(i));
       // System.out.println("columnName="+tabInfo.getColumnName(i));

      }
     // 搜索有几条纪录，放到可回读的图元集中
     RewindableFeatureSet rFtrSet = new RewindableFeatureSet(world.searchAll(columns, null));
     // 得到第一个图元，图元集中的图元没有顺序
     ftr=rFtrSet.getNextFeature();
     // then loop through all features in the layer
     while (ftr!=null)
    {
/* get the first attribute (columnData) from the feature Note: If
you want to re-use the Attribute object later on (after the
getNextFeature loop), you would need to make a copy of the
Attribute object, using the copy constructor.
*/
      //得到一个图元的第一个属性
     attrib = ftr.getAttribute(0);
     System.out.println("attribute="+attrib.toString());
     //得到一个图元的属性数目
     attribCount = ftr.getAttributeCount();
     System.out.println("attributeCount="+attribCount);
     //得到几何信息
     geom = ftr.getGeometry();
     //如果该元素是点
      if (geom.getType()==Geometry.TYPE_POINT)
      {
       System.out.println("aaaaaaaaaaaa");
     //把该元素转换成点元素
      pntGeometry = (PointGeometry)geom;
     //得到该点元素的边界
      rect = pntGeometry.getBounds();
      System.out.println(rect.toString());
     //得到该点元素的标注位置
      dblPnt = pntGeometry.getLabelPoint(null);
      }
      else //如果不是点元素，就可用VectorGeometry来存储
      {
     //将元素转换成 Vector geometry
      vectorGeometry = (VectorGeometry)geom;
     // get the minimum bounding rectangle for the feature
      rect = vectorGeometry.getBounds();
     // get the x,y location where the feature’s label will be anchored
      dblPnt = vectorGeometry.getLabelPoint(null);
      System.out.println("dblPnt:"+dblPnt.toString());
      double[] pnts;
      int offset=0;
      int numPts;
// Loop through all the point groups and then put the points into an array
      //无论是线元素还是区域都是由点构成的
      for (int i=0;i<vectorGeometry.getPointListCount();++i)
      {
        // Get the next Point List
      pntList = vectorGeometry.getNextPointList();
        // determine the number of Points in the point group
      numPts = pntList.getPointCount();
        // Create the point array large enough to hold all the points
      pnts = new double[numPts];
       // Call getNextPoints which will put the points into the array
      pntList.getNextPoints(pnts, offset, numPts/2);
      //System.out.println("numPts="+numPts);
      }
      }
      // Get the next feature
      ftr=rFtrSet.getNextFeature();
      }
      // Rewind the FeatureSet to prepare for future use重新回到第一个图元
      rFtrSet.rewind();

    }catch(Exception e){
        System.out.println("Error");
        e.printStackTrace();
      }
    }

    public static void main(String args[]){
    FeatureTest bclr=new FeatureTest();
 }

}