org.yamcs.xtce.PathElement Maven / Gradle / Ivy
package org.yamcs.xtce;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
/**
* Describes an element from an aggregate/array member access path For example, the third element from this path :
* a/c[2]/d[0][5]/x
* is:
* name = "d"
* index = [0, 5]
*
* both name and index can be null
*/
public class PathElement implements Serializable {
private static final long serialVersionUID = 1L;
final String name;
final int[] index;
public PathElement(String name, int[] index) {
this.name = name;
this.index = index;
}
/**
* Encodes the path element into a string like
*
*
* name[idx_1][idx_2]..[idx_n]
*
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
if (name != null) {
sb.append(name);
}
if (index != null) {
for (int i = 0; i < index.length; i++) {
sb.append("[").append(index[i]).append("]");
}
}
return sb.toString();
}
/**
* Creates a path element from a string like
*
*
* name[idx_1][idx_2]..[idx_n]
*
*/
public static PathElement fromString(String s) {
List idx = new ArrayList<>();
int k = s.indexOf('[', 0);
if (k == -1) {
return new PathElement(s, null);
}
String name = k > 0 ? s.substring(0, k) : null;
while (true) {
k = s.indexOf('[', k);
if (k == -1) {
break;
}
int k2 = s.indexOf(']', k);
if (k2 == -1) {
throw new IllegalArgumentException("Invalid aggregate member path '" + s + "'");
}
int n = Integer.parseInt(s.substring(k + 1, k2));
if (n < 0) {
throw new IllegalArgumentException("Negative array index: " + n);
}
idx.add(n);
k = k2;
}
int[] idx1 = null;
if (!idx.isEmpty()) {
idx1 = new int[idx.size()];
for (int u = 0; u < idx.size(); u++) {
idx1[u] = idx.get(u);
}
}
return new PathElement(name, idx1);
}
public String getName() {
return name;
}
public int[] getIndex() {
return index;
}
/**
* Transforms the path into a string like
* a/c[2]/d[0][5]/x
*
* @param path
* @return
*/
public static String pathToString(PathElement[] path) {
if (path == null) {
return "null";
}
StringBuilder sb = new StringBuilder();
boolean first = true;
for (PathElement pe : path) {
if (first) {
first = false;
} else {
sb.append("/");
}
sb.append(pe.toString());
}
return sb.toString();
}
}