org.apache.ibatis.reflection.ParamNameResolver Maven / Gradle / Ivy
/**
* Copyright 2009-2017 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ibatis.reflection;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.binding.MapperMethod.ParamMap;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
public class ParamNameResolver {
private static final String GENERIC_NAME_PREFIX = "param";
/**
*
* The key is the index and the value is the name of the parameter.
* The name is obtained from {@link Param} if specified. When {@link Param} is not specified,
* the parameter index is used. Note that this index could be different from the actual index
* when the method has special parameters (i.e. {@link RowBounds} or {@link ResultHandler}).
*
*
* - aMethod(@Param("M") int a, @Param("N") int b) -> {{0, "M"}, {1, "N"}}
* - aMethod(int a, int b) -> {{0, "0"}, {1, "1"}}
* - aMethod(int a, RowBounds rb, int b) -> {{0, "0"}, {2, "1"}}
*
*/
private final SortedMap names;
private boolean hasParamAnnotation;
public ParamNameResolver(Configuration config, Method method) {
final Class[] paramTypes = method.getParameterTypes();
final Annotation[][] paramAnnotations = method.getParameterAnnotations();
final SortedMap map = new TreeMap();
int paramCount = paramAnnotations.length;
// get names from @Param annotations
for (int paramIndex = 0; paramIndex < paramCount; paramIndex++) {
if (isSpecialParameter(paramTypes[paramIndex])) {
// skip special parameters
continue;
}
String name = null;
for (Annotation annotation : paramAnnotations[paramIndex]) {
if (annotation instanceof Param) {
hasParamAnnotation = true;
name = ((Param) annotation).value();
break;
}
}
if (name == null) {
// @Param was not specified.
if (config.isUseActualParamName()) {
name = getActualParamName(method, paramIndex);
}
if (name == null) {
// use the parameter index as the name ("0", "1", ...)
// gcode issue #71
name = String.valueOf(map.size());
}
}
map.put(paramIndex, name);
}
names = Collections.unmodifiableSortedMap(map);
}
private String getActualParamName(Method method, int paramIndex) {
if (Jdk.parameterExists) {
return ParamNameUtil.getParamNames(method).get(paramIndex);
}
return null;
}
private static boolean isSpecialParameter(Class clazz) {
return RowBounds.class.isAssignableFrom(clazz) || ResultHandler.class.isAssignableFrom(clazz);
}
/**
* Returns parameter names referenced by SQL providers.
*/
public String[] getNames() {
return names.values().toArray(new String[0]);
}
/**
*
* A single non-special parameter is returned without a name.
* Multiple parameters are named using the naming rule.
* In addition to the default names, this method also adds the generic names (param1, param2,
* ...).
*
*/
public Object getNamedParams(Object[] args) {
final int paramCount = names.size();
if (args == null || paramCount == 0) {
return null;
} else if (!hasParamAnnotation && paramCount == 1) {
return args[names.firstKey()];
} else {
final Map param = new ParamMap