我正在尝试使用Java Spatial Index Library,但无法加载examples。
当我尝试从示例中的Eclipse Kepler中打开以下文件时,Eclipse抱怨TIntProcedure
无法解析:
package net.sourceforge.jsi.examples;
import gnu.trove.*;
import java.util.ArrayList;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.infomatiq.jsi.Rectangle;
import com.infomatiq.jsi.SpatialIndex;
import com.infomatiq.jsi.rtree.RTree;
public class Contains {
private static final Logger log = LoggerFactory.getLogger(Contains.class);
public static void main(String[] args) {
new Contains().run();
}
private void run() {
// Create and initialize an rtree
SpatialIndex si = new RTree();
si.init(null);
// We have some points or rectangles in some other data structure.
// The rtree can handle millions of these.
Rectangle[] rects = new Rectangle[] {
new Rectangle(0, 0, 0, 0),
new Rectangle(0, 1, 0, 1),
new Rectangle(1, 0, 1, 0),
new Rectangle(1, 1, 1, 1),
};
// Add our data to the rtree. Every time we add a rectangle we give it
// an ID. This ID is what is returned by querying the rtree. In this
// example we use the array index as the ID.
for (int i = 0; i < rects.length; i++) {
si.add(rects[i], i);
}
// Now see which of these points is contained by some
// other rectangle. The rtree returns the results of a query
// by calling the execute() method on a TIntProcedure.
// In this example we want to save the results of the query
// into a list, so that's what the execute() method does.
class SaveToListProcedure implements TIntProcedure {
private List<Integer> ids = new ArrayList<Integer>();
@Override
public boolean execute(int id) {
ids.add(id);
return true;
};
private List<Integer> getIds() {
return ids;
}
};
SaveToListProcedure myProc = new SaveToListProcedure();
si.contains(new Rectangle(-0.5f, -0.5f, 1.5f, 0.5f), myProc);
List<Integer> ids = myProc.getIds();
for (Integer id : ids) {
log.info(rects[id].toString() + " was contained");
}
// Actually that was a really long winded (and inefficient) way of
// printing out the rectangles. Would be better to use an anonymous
// class to just do the printing inside the execute method. That is
// what the NearestN class does.
}
}
TIntProcedure
似乎来自gnu trove包,但是TIntProcedure
接口实际上是在gnu.trove.procedure
中定义的,而不是在gnu.trove
中定义的。我使用了错误的
TIntProcedure
吗? Eclipse可以使用SaveToListProcedure
声明,但在si.contains(new Rectangle(-0.5f, -0.5f, 1.5f, 0.5f), myProc)
行显示警告。无论如何,我还是尝试运行该项目,只是为了查看Eclipse是否抛出了错误错误,但它的错误信息如下:Exception in thread "main" java.lang.Error: Unresolved compilation problem:
at net.sourceforge.jsi.examples.Contains.main(Contains.java:18)
在第18行定义了
main
。 最佳答案
JSI正在使用Trove 2.0.2。直到3.x,他们才将TIntProcedure移入该软件包。对该软件包进行明显降级对我而言有效。
关于java - TIntProcedure无法解决,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/21293856/