/* 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.camunda.bpm.engine.impl;
import java.io.Serializable;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.camunda.bpm.engine.ProcessEngineException;
import org.camunda.bpm.engine.impl.context.Context;
import org.camunda.bpm.engine.impl.interceptor.Command;
import org.camunda.bpm.engine.impl.interceptor.CommandContext;
import org.camunda.bpm.engine.impl.interceptor.CommandExecutor;
import org.camunda.bpm.engine.query.NativeQuery;
/**
* Abstract superclass for all native query types.
*
* @author Bernd Ruecker (camunda)
*/
public abstract class AbstractNativeQuery<T extends NativeQuery< ? , ? >, U> implements Command<Object>, NativeQuery<T, U>,
Serializable {
private static final long serialVersionUID = 1L;
private static enum ResultType {
LIST, LIST_PAGE, SINGLE_RESULT, COUNT
}
protected transient CommandExecutor commandExecutor;
protected transient CommandContext commandContext;
protected int maxResults = Integer.MAX_VALUE;
protected int firstResult = 0;
protected ResultType resultType;
private Map<String, Object> parameters = new HashMap<String, Object>();
private String sqlStatement;
protected AbstractNativeQuery(CommandExecutor commandExecutor) {
this.commandExecutor = commandExecutor;
}
public AbstractNativeQuery(CommandContext commandContext) {
this.commandContext = commandContext;
}
public AbstractNativeQuery<T, U> setCommandExecutor(CommandExecutor commandExecutor) {
this.commandExecutor = commandExecutor;
return this;
}
@SuppressWarnings("unchecked")
public T sql(String sqlStatement) {
this.sqlStatement = sqlStatement;
return (T) this;
}
@SuppressWarnings("unchecked")
public T parameter(String name, Object value) {
parameters.put(name, value);
return (T) this;
}
@SuppressWarnings("unchecked")
public U singleResult() {
this.resultType = ResultType.SINGLE_RESULT;
if (commandExecutor != null) {
return (U) commandExecutor.execute(this);
}
return executeSingleResult(Context.getCommandContext());
}
@SuppressWarnings("unchecked")
public List<U> list() {
this.resultType = ResultType.LIST;
if (commandExecutor != null) {
return (List<U>) commandExecutor.execute(this);
}
return executeList(Context.getCommandContext(), getParameterMap(), 0, Integer.MAX_VALUE);
}
@SuppressWarnings("unchecked")
public List<U> listPage(int firstResult, int maxResults) {
this.firstResult =firstResult;
this.maxResults = maxResults;
this.resultType = ResultType.LIST_PAGE;
if (commandExecutor!=null) {
return (List<U>) commandExecutor.execute(this);
}
return executeList(Context.getCommandContext(), getParameterMap(), firstResult, maxResults);
}
public long count() {
this.resultType = ResultType.COUNT;
if (commandExecutor != null) {
return (Long) commandExecutor.execute(this);
}
return executeCount(Context.getCommandContext(), getParameterMap());
}
public Object execute(CommandContext commandContext) {
if (resultType == ResultType.LIST) {
return executeList(commandContext, getParameterMap(), 0, Integer.MAX_VALUE);
} else if (resultType == ResultType.LIST_PAGE) {
Map<String, Object> parameterMap = getParameterMap();
parameterMap.put("resultType", "LIST_PAGE");
parameterMap.put("firstResult", firstResult);
parameterMap.put("maxResults", maxResults);
parameterMap.put("orderBy", "RES.ID_ asc");
int firstRow = firstResult + 1;
parameterMap.put("firstRow", firstRow);
int lastRow = 0;
if(maxResults == Integer.MAX_VALUE) {
lastRow = maxResults;
}
lastRow = firstResult + maxResults + 1;
parameterMap.put("lastRow", lastRow);
return executeList(commandContext, parameterMap, firstResult, maxResults);
} else if (resultType == ResultType.SINGLE_RESULT) {
return executeSingleResult(commandContext);
} else {
return executeCount(commandContext, getParameterMap());
}
}
public abstract long executeCount(CommandContext commandContext, Map<String, Object> parameterMap);
/**
* Executes the actual query to retrieve the list of results.
* @param maxResults
* @param firstResult
*
* @param page
* used if the results must be paged. If null, no paging will be
* applied.
*/
public abstract List<U> executeList(CommandContext commandContext, Map<String, Object> parameterMap, int firstResult, int maxResults);
public U executeSingleResult(CommandContext commandContext) {
List<U> results = executeList(commandContext, getParameterMap(), 0, Integer.MAX_VALUE);
if (results.size() == 1) {
return results.get(0);
} else if (results.size() > 1) {
throw new ProcessEngineException("Query return " + results.size() + " results instead of max 1");
}
return null;
}
private Map<String, Object> getParameterMap() {
HashMap<String, Object> parameterMap = new HashMap<String, Object>();
parameterMap.put("sql", sqlStatement);
parameterMap.putAll(parameters);
return parameterMap;
}
public Map<String, Object> getParameters() {
return parameters;
}
}