Fix map and array mapping from CompilingResultSetMapper, add javadocs

This commit is contained in:
Travis Burtrum 2017-05-17 11:18:58 -04:00
parent 61010ec39e
commit 34a7a55bfc
2 changed files with 59 additions and 10 deletions

View File

@ -7,6 +7,14 @@ import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;
/**
* This generally follows the contract of ResultSetMapper, with the differences specified in CompilingRowToObjectMapper.
* <p>
* This does cache compiled code based on column name/order and DTO being mapped to, so the (rather heavy)
* code generation/compilation/instantiation only happens once for each query/dto, and is very fast on subsequent calls.
*
* @see CompilingRowToObjectMapper
*/
public class CompilingResultSetMapper extends ResultSetMapper {
protected final Compiler compiler = new Compiler();

View File

@ -12,7 +12,19 @@ import java.util.Calendar;
import java.util.Map;
/**
* Created by mopar on 5/16/17.
* Map a ResultSet row to an Object. This mapper generates/compiles/executes java code to perform the mapping.
*
* @author Travis Burtrum (modifications from beehive)
* @author Travis Burtrum
* @see RowToObjectMapper for most details, will document here where this differs
* <p>
* Usage differences:
* 1. Reflection can set non-public or final fields directly, direct java code cannot, so DTOs like that will result in
* a compilation and therefore mapping error.
* <p>
* Subclass differences:
* 1. Normally a subclass of RowToObjectMapper can overload the getMapImplementation() method to change some behavior,
* @see CaseInsensitiveMapRowToObjectMapper , but that method is never called with this implementation.
*/
public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
protected final Compiler compiler;
@ -72,12 +84,42 @@ public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
}
protected String typeFromName(final Class<?> type) {
return type.getName(); // todo: naive for now
if (returnMap || componentType == null)
return type.getName();
else {
// an array, annoying syntax
final String name = type.getName();
final char charType = name.charAt(1);
switch (charType) {
case 'L':
return name.substring(2, name.length() - 1) + "[]";
case 'Z':
return "boolean[]";
case 'B':
return "byte[]";
case 'C':
return "char[]";
case 'D':
return "double[]";
case 'F':
return "float[]";
case 'I':
return "int[]";
case 'J':
return "long[]";
case 'S':
return "short[]";
case '[':
default:
throw new MapperException("only supports single dimensional array");
}
}
}
protected String escapeJavaString(final String s) {
protected String escapeMapKeyString(final String s) {
// todo: escape key string, newlines, double quotes, backslashes...
return s;
// actually it seems like those wouldn't be valid SQL column names, so we won't bother until we hear different...
return '"' + s + '"';
}
// code generation down here
@ -110,19 +152,19 @@ public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
if (returnMap) // we want a map
try {
// todo: does not call getMapImplementation, I think that's fine
java.append("final Map<String, Object> ret = new ").append(tType).append("<String, Object>();\n");
java.append("final ").append(tType).append("<String, Object> ret = new ").append(tType).append("<String, Object>();\n");
final ResultSetMetaData md = _resultSet.getMetaData();
final int columnLength = _columnCount + 1;
if (componentType != null && componentType != Object.class) { // we want a specific value type
int typeId = _tmf.getTypeId(componentType);
for (int x = 1; x < columnLength; ++x) {
java.append("ret.put(").append(escapeJavaString(md.getColumnName(x).toLowerCase())).append(", ");
java.append("ret.put(").append(escapeMapKeyString(md.getColumnName(x).toLowerCase())).append(", ");
extractColumnValueString(java, x, typeId);
java.append(");\n");
}
} else // we want a generic object type
for (int x = 1; x < columnLength; ++x)
java.append("ret.put(").append(escapeJavaString(md.getColumnName(x).toLowerCase())).append(", rs.getObject(").append(x).append("));\n");
java.append("ret.put(").append(escapeMapKeyString(md.getColumnName(x).toLowerCase())).append(", rs.getObject(").append(x).append("));\n");
java.append("return ret;\n");
return;
} catch (Throwable e) {
@ -132,8 +174,7 @@ public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
}
else if (componentType != null) // we want an array
try {
// todo: array initialization syntax?
java.append("final ").append(tType).append("[] ret = new ").append(tType).append("[").append(_columnCount).append("];\n");
java.append("final ").append(tType).append(" ret = new ").append(tType.substring(0, tType.length() - 1)).append(_columnCount).append("];\n");
final int typeId = _tmf.getTypeId(componentType);
for (int x = 0; x < _columnCount; ) {
java.append("ret[").append(x).append("] = ");
@ -141,6 +182,7 @@ public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
java.append(";\n");
}
java.append("return ret;\n");
return;
} catch (Throwable e) {
throw new MapperException(e.getClass().getName() + " when trying to create a "
+ componentType.getName() + "[] from a ResultSet row, all columns must be of that type", e);
@ -236,7 +278,6 @@ public class CompilingRowToObjectMapper<T> extends RowToObjectMapper<T> {
* @throws java.sql.SQLException on error.
*/
protected void extractColumnValueString(final StringBuilder java, final int index, final int resultType) {
// todo: custom boolean
switch (resultType) {
case TypeMappingsFactory.TYPE_INT:
java.append("rs.getInt(").append(index).append(")");