com.avaje.ebeaninternal.server.query.SqlTreeAlias Maven / Gradle / Ivy
package com.avaje.ebeaninternal.server.query;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import com.avaje.ebeaninternal.server.deploy.BeanDescriptor;
import com.avaje.ebeaninternal.server.el.ElPropertyDeploy;
/**
* Special Map of the logical property joins to table alias.
*
* @author rbygrave
*/
public class SqlTreeAlias {
private int counter;
private int manyWhereCounter;
private final TreeSet joinProps = new TreeSet();
private HashSet embeddedPropertyJoins;
private final TreeSet manyWhereJoinProps = new TreeSet();
private final HashMap aliasMap = new HashMap();
private final HashMap manyWhereAliasMap = new HashMap();
private final String rootTableAlias;
public SqlTreeAlias(String rootTableAlias) {
this.rootTableAlias = rootTableAlias;
}
/**
* Add joins to support where predicates
*/
public void addManyWhereJoins(Set manyWhereJoins) {
if (manyWhereJoins != null) {
for (String include : manyWhereJoins) {
addPropertyJoin(include, manyWhereJoinProps);
}
}
}
private void addEmbeddedPropertyJoin(String embProp) {
if (embeddedPropertyJoins == null) {
embeddedPropertyJoins = new HashSet();
}
embeddedPropertyJoins.add(embProp);
}
/**
* Add joins.
*/
public void addJoin(Set propJoins, BeanDescriptor desc) {
if (propJoins != null) {
for (String propJoin : propJoins) {
ElPropertyDeploy elProp = desc.getElPropertyDeploy(propJoin);
if (elProp != null && elProp.getBeanProperty().isEmbedded()) {
addEmbeddedPropertyJoin(propJoin);
} else {
addPropertyJoin(propJoin, joinProps);
}
}
}
}
private void addPropertyJoin(String include, TreeSet set) {
if (set.add(include)) {
String[] split = SplitName.split(include);
if (split[0] != null) {
addPropertyJoin(split[0], set);
}
}
}
/**
* Build a set of table alias for the given bean and fetch joined properties.
*/
public void buildAlias() {
for (String joinProp : joinProps) {
calcAlias(joinProp);
}
for (String joinProp : manyWhereJoinProps) {
calcAliasManyWhere(joinProp);
}
mapEmbeddedPropertyAlias();
}
private void mapEmbeddedPropertyAlias() {
if (embeddedPropertyJoins != null) {
for (String propJoin : embeddedPropertyJoins) {
String[] split = SplitName.split(propJoin);
// the table alias of the parent path
String alias = getTableAlias(split[0]);
aliasMap.put(propJoin, alias);
}
}
}
private String calcAlias(String prefix) {
String alias = nextTableAlias();
aliasMap.put(prefix, alias);
return alias;
}
private void calcAliasManyWhere(String prefix) {
String alias = nextManyWhereTableAlias();
manyWhereAliasMap.put(prefix, alias);
}
/**
* Return the table alias for a given property name.
*/
public String getTableAlias(String prefix) {
if (prefix == null) {
return rootTableAlias;
} else {
String s = aliasMap.get(prefix);
if (s == null) {
return calcAlias(prefix);
}
return s;
}
}
/**
* Return an alias using "Many where joins".
*/
public String getTableAliasManyWhere(String prefix) {
if (prefix == null) {
return rootTableAlias;
}
String s = manyWhereAliasMap.get(prefix);
if (s == null) {
s = aliasMap.get(prefix);
}
if (s == null) {
String msg = "Could not determine table alias for [" + prefix + "] manyMap[" + manyWhereAliasMap + "] aliasMap[" + aliasMap + "]";
throw new RuntimeException(msg);
}
return s;
}
/**
* Parse for where clauses that uses "Many where joins"
*/
public String parseWhere(String clause) {
clause = parseRootAlias(clause);
clause = parseAliasMap(clause, manyWhereAliasMap);
return parseAliasMap(clause, aliasMap);
}
/**
* Parse without using any extra "Many where joins".
*/
public String parse(String clause) {
clause = parseRootAlias(clause);
return parseAliasMap(clause, aliasMap);
}
/**
* Parse the clause replacing the table alias place holders.
*/
private String parseRootAlias(String clause) {
if (rootTableAlias == null) {
return clause.replace("${}", "");
} else {
return clause.replace("${}", rootTableAlias + ".");
}
}
/**
* Parse the clause replacing the table alias place holders.
*/
private String parseAliasMap(String clause, HashMap parseAliasMap) {
for (Map.Entry e : parseAliasMap.entrySet()) {
String k = "${" + e.getKey() + "}";
clause = clause.replace(k, e.getValue() + ".");
}
return clause;
}
/**
* Return the next valid table alias given the preferred table alias.
*/
private String nextTableAlias() {
return "t" + (++counter);
}
private String nextManyWhereTableAlias() {
return "u" + (++manyWhereCounter);
}
/**
* Return true if there are joins included in the query.
*/
public boolean isIncludeJoins() {
return !aliasMap.isEmpty() || !manyWhereAliasMap.isEmpty();
}
}