shapefilereader.java

geotools的源码

package uk.ac.leeds.ccg.geotools;

import java.lang.*;
import cmp.LEDataStream.*;
import uk.ac.leeds.ccg.shapefile.*;
import uk.ac.leeds.ccg.dbffile.*;
import java.io.*;
import java.net.*;
import java.util.zip.*;
import java.util.*;
import java.awt.Color;

/**
 * A class to simplify the process of loading an ESRI(r) Shapefile.
 * It is effectivly a wrapper for the Shapefile class.<p>
 * This class will open the shapefile (both .shp and .dbf if avaiable)
 * after which calls to readLines,readPolygons and readData will extract
 * the necasary information out of the shapefile.<p>
 * The class also has a series of getTheme() methods that encapsulate the process
 * of building themes (complet with layer and shaders) as a v.easy way of setting up a theme
 * for inclusion in a viewer.
 * @author James Macgill, Center for computational Geography.
 * @author David Robison ArcM code and bug fixes
 */
public class ShapefileReader extends java.lang.Object implements DataSource {
    public static final String cvsid="$Id: ShapefileReader.java,v 1.33 2001/12/09 16:06:40 jmacgill Exp $";
    private final static boolean DEBUG=false;
    public Shapefile sf = null;
    public Dbf dbf = null;
    private int idCol = 3;//best general guess
    private String name = "none";
    private MixedLayer map = new MixedLayer(this);
    private Loader loader;
    
    /**
     * Creates and opens a new ShapefileReader
     * @param baseFilename: name of file without extention e.g. 'name' not 'name.shp'
     */
    public ShapefileReader(String baseFilename){
        
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        name = baseFilename;
        try{
            sf = new Shapefile(baseFilename+".shp");
        } catch(Exception e)
        {System.out.println("SfR->"+e);return;}
        
        try{
            File dbffile = new File(baseFilename+".dbf");
            dbf = new Dbf(dbffile);
            getIds();
        } catch(Exception e) {System.out.println("SfR->"+e);return;}
    }
    
    public ShapefileReader(String baseFilename, int idCol){
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        this.idCol = idCol;
        name = baseFilename;
        try {
            sf = new Shapefile(baseFilename+".shp");
        } catch(Exception e)
        {System.out.println("SfR->"+e);}
        
        try {
            File dbffile = new File(baseFilename+".dbf");
            dbf = new Dbf(dbffile);
            getIds();
        } catch(Exception e)
        {System.out.println("SfR->"+e);}
    }
    URL base;
    int status = 0;
    /**
     * Creates and opens a new ShapefileReader
     * If at all posible, this is the contstuctor that should be used.
     * @param base: url of file without extention e.g. 'name' not 'name.shp'
     * @param idCol An int giving the number of the colum to take the feature ids from.
     */
    public ShapefileReader(URL base,int idCol){
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        //if(base.toString().endsWith(".shp")
        this.idCol=idCol;
        this.base = base;
        map.setStatus(map.PENDING);
        name = base.getFile();
        loader = new Loader();
        //loader.start();
        
        //the following block of code effectivly dissables the threaded loading system for now
        /*try{
        loader.join();
        }
        catch(InterruptedException ie){
            System.err.println("Shapefile not loaded by loader "+ie);
        }*/
        loader.run();//bypass threading and run from here
        System.out.println("Shapefile Constructor Finished - tread loading disabled");
    }
    
    /**
     * Creates and opens a new ShapefileReader
     * @param shp: InputStream to the .shp file
     * @param dbf: InputStream to the .dbf file (can be null)
     * @param idCol An int giving the number of the colum to take the feature ids from.
     */
    public ShapefileReader(InputStream shpIn,InputStream dbfIn,int idCol){
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        this.idCol=idCol;
        //name = ???
        try{
            sf = new Shapefile(shpIn);
            if(dbfIn!=null){
                dbf = new Dbf(dbfIn);
            }
            getIds();
        }catch(Exception e){System.err.println("SfR->"+e);}
    }
    
    /**
     * Creates and opens a new ShapefileReader
     * @param shp: InputStream to the .shp file
     * @param dbf: InputStream to the .dbf file (can be null)
     * @param idCol An int giving the number of the colum to take the feature ids from.
     */
    public ShapefileReader(InputStream shpIn,InputStream dbfIn){
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        //name = ???
        
        try{
            sf = new Shapefile(shpIn);
            if(dbfIn!=null){
                dbf = new Dbf(dbfIn);
            }
        }catch(Exception e){System.err.println("SfR->"+e);}
        guessIdCol();
        getIds();
    }
    
    /**
     * Constructs a shapefile reader from a base url.
     * This is the best constructor to use if you do not know the id column for the shapefile
     * @param base The base url for the shapefile (i.e. leave the .shp off the end if possible)
     */
    public ShapefileReader(URL base){
        this(base,-1);
        if(DEBUG)System.out.println("---->uk.ac.leeds.ccg.geotools.ShapefileReader constructed. Will identify itself as SfR->");
        //try and figure out id col
        
    }
    
    private void guessIdCol(){
        switch(sf.getShapeType()){
            case(Shapefile.POLYGON):
                idCol = 2;
                break;
            case(Shapefile.ARC_M):
                idCol = 5;
                break;
            case(Shapefile.ARC):
                idCol = 5;
                break;
            case(Shapefile.POINT):
                idCol = 3;
                break;
        }
        if(DEBUG)System.out.println("SfR->ID col first guessed at "+idCol+" "+dbf.getNumFields());
        // attempt to solve sourceforge bug #122495 - ian
        if(dbf==null) return;
        if(idCol> dbf.getNumFields()-1){// whoops guessed wrong!
            idCol=0; // probably not right but safe?
        }
        if(DEBUG)System.out.println("SfR->ID col guessed at "+idCol+" "+dbf.getNumFields());
    }
    
    public void setIdCol(int col){
        idCol = col;
    }
    
    public void setIdCol(String name){
        int col = dbf.getFieldNumber(name);
        idCol = (col>=0)?col:idCol;
        getIds();
    }
    
    public int getIdCol(){
        return idCol;
    }
    
    
    /**
     * gets the shape type for this shapefile.
     *
     * @return int The type of feature, constants defined in shapefile
     * match the values given, for example Shapefile.POLYGON;
     *
     */
    public int getShapeType(){
        return sf.getShapeType();
    }
    
    /**
     * Reads the data in this shapefile and produces a theme for
     * use in a Viewer.
     * @return Theme a theme containing the features of the shapefile
     */
    public Theme getTheme(){
        Theme t = new Theme(this.getLayer());
        t.setName(name);
        return t;
    }
    /**
     * Reads the data in this shapefile and produces a layer for
     * use in a Theme.
     * @return Layer a Layer containing the features of the shapefile
     */
    public Layer getLayer(){
        return map;
        
        //return l;
    }
    
    
    /**
     * Gets a theme based on the given shader and colName
     * as a bonus the method configures the shaders range
     * for you by reading the min and max values from the named column
     * @param shade a RampShader to shade this theme (includes HSV,sat and val shaders)
     * @param colName the name of the column to grab the data from
     */
    public Theme getTheme(Shader shade,String colName){
        Theme t = getTheme();
        SimpleGeoData data = new SimpleGeoData();
        data.setName(colName);
        t.setGeoData(data);
        shade.setRange(data);
        t.setShader(shade);
        AddDataWhenReady dataWatch = new AddDataWhenReady(data,colName);
        dataWatch.start();
        return t;
    }
    
    class AddDataWhenReady extends Thread{
        SimpleGeoData data;
        String colName;
        int col;
        public AddDataWhenReady(SimpleGeoData data,String colName){
            this.data = data;
            this.colName = colName;
        }
        public AddDataWhenReady(SimpleGeoData data,int col){
            this.data = data;
            this.colName = colName;
        }
        public void run(){
            System.out.println("Waiting for data loader to finish");
            try{
                loader.join();
            }
            catch(InterruptedException ie){
                System.err.println("AddDataWhenReady stuck because "+ie);
                return;
            }
            System.out.println("Apparently data loader has now finished");
            if(colName !=null){
                col = dbf.getFieldNumber(colName);
            }
                if(col>=0){
                    readDataNow(data,col);
                }
                else{
                    if(DEBUG)System.err.println("SfR->Column "+colName+" not found in .dbf file");
                }