io.ebeaninternal.server.deploy.DetermineAggPath Maven / Gradle / Ivy
package io.ebeaninternal.server.deploy;
import io.ebeaninternal.server.deploy.meta.DeployBeanDescriptor;
import io.ebeaninternal.server.deploy.meta.DeployBeanProperty;
import io.ebeaninternal.server.deploy.meta.DeployBeanPropertyAssocMany;
import io.ebeaninternal.server.deploy.meta.DeployBeanPropertyAssocOne;
class DetermineAggPath {
/**
* Return the many path for the given aggregation formula.
*/
static String manyPath(String aggregation, DeployBeanDescriptor desc) {
DetermineAggPath.Path path = paths(aggregation);
if (path.length() == 1) {
// a top level aggregation (so here we need to exclude Id property)
return null;
}
return path.getManyPath(0, desc);
}
static Path paths(String aggregation) {
String aggPath = path(aggregation);
return new Path(aggPath.split("\\."), aggregation);
}
/**
* Parse and return the full path for the aggregation.
*/
static String path(String aggregation) {
// aggregations always have a form of sum(), avg(), max(), count() etc
// so find the first open bracket
int start = aggregation.indexOf('(');
if (start == -1) {
throw new IllegalArgumentException("Aggregation formula [" + aggregation + "] is expected to have a '(' ?");
}
for (int i = start + 1; i < aggregation.length(); i++) {
char ch = aggregation.charAt(i);
if (!isNamePart(ch)) {
return aggregation.substring(start + 1, i);
}
}
throw new IllegalArgumentException("Could not find path in aggregation formula [" + aggregation + "]");
}
private static boolean isNamePart(char ch) {
return ch == '.' || Character.isJavaIdentifierPart(ch);
}
/**
* Helper class holding aggregation path segments.
*/
static class Path {
final String aggregation;
final String[] paths;
Path(String[] paths, String aggregation) {
this.paths = paths;
this.aggregation = aggregation;
}
int length() {
return paths.length;
}
String path(int pos) {
if (pos == 0) {
return paths[0];
} else {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < pos; i++) {
if (i > 0) {
sb.append(".");
}
sb.append(paths[i]);
}
return sb.toString();
}
}
String getManyPath(int pos, DeployBeanDescriptor desc) {
while (true) {
String path = paths[pos];
DeployBeanProperty details = desc.getBeanProperty(path);
if (details instanceof DeployBeanPropertyAssocMany) {
return path(pos);
} else if (details instanceof DeployBeanPropertyAssocOne) {
DeployBeanPropertyAssocOne one = (DeployBeanPropertyAssocOne) details;
DeployBeanDescriptor targetDesc = one.getTargetDeploy();
desc = targetDesc;
pos = pos + 1;
continue;
}
throw new IllegalArgumentException("Can not find path to many in aggregation formula [" + aggregation + "]");
}
}
}
}