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io.github.afezeria.freedao.classic.runtime.context.PageQueryContext Maven / Gradle / Ivy
package io.github.afezeria.freedao.classic.runtime.context;
import io.github.afezeria.freedao.StatementType;
import io.github.afezeria.freedao.classic.runtime.*;
import io.github.afezeria.freedao.classic.runtime.dialect.DatabaseDialect;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.expression.ExpressionVisitorAdapter;
import net.sf.jsqlparser.expression.JdbcParameter;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.statement.select.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
/**
* @author afezeria
*/
public class PageQueryContext extends DaoContext {
private static final Logger logger = LoggerFactory.getLogger(PageQueryContext.class);
public static ThreadLocal> local = new ThreadLocal<>();
private static final Map, Boolean> disableParseSqlFlag = new ConcurrentHashMap<>();
@Override
@SuppressWarnings("unchecked")
public T execute(SqlSignature signature, Object[] methodArgs, String sql, List sqlArgs, SqlExecutor executor, ResultHandler resultHandler) {
Page page = local.get();
if (page == null) {
return getDelegate().execute(signature, methodArgs, sql, sqlArgs, executor, resultHandler);
}
if (page.getRecords() != null) {
throw new IllegalStateException("the closure of DaoHelper.page can only contain one query");
}
if (signature.getType() != StatementType.SELECT) {
throw new IllegalArgumentException(signature.getType() + " statement does not support paging");
}
if (!Collection.class.isAssignableFrom(signature.getReturnType())) {
throw new IllegalArgumentException("single row query does not support paging");
}
Select select = null;
try {
if (disableParseSqlFlag.get(signature) == null) {
select = (Select) CCJSqlParserUtil.parse(sql);
}
} catch (JSQLParserException e) {
disableParseSqlFlag.put(signature, true);
logger.debug("parse sql failure", e);
} catch (ClassCastException e) {
disableParseSqlFlag.put(signature, true);
throw new RuntimeException("cannot convert non select sql into a paged sql");
}
Select finalSelect = select;
return getDelegate().withConnection(connection -> {
try {
if (!page.isSkipCount() && !page.isOrderByOnly()) {
long count = execCountSql(connection, finalSelect, signature, sql, sqlArgs);
page.setTotal(count);
int offset = (page.getPageIndex() - 1) * page.getPageSize();
logger.debug("count: {}, offset:{}", count, page.getOffset());
if (count == 0L || offset >= count) {
page.setRecords(new ArrayList());
return null;
}
}
SqlAndParamIndexPair pair = optimizeSql(finalSelect,
sql,
!page.isOrderByOnly(),
!page.isOrderByOnly(),
page.getOrderBy() != null,
true);
String pageSql = DatabaseDialect.getDialect(connection.getMetaData().getDatabaseProductName())
.getPageSql(page, pair.sql);
for (Integer idx : pair.indexOfParameterToSkip) {
sqlArgs.remove(idx - 1);
}
T result = getDelegate().execute(signature, methodArgs, pageSql, sqlArgs, executor, resultHandler);
page.setRecords(new ArrayList(((Collection) result)));
return result;
} catch (SQLException e) {
throw new RuntimeException(e);
}
});
}
/**
* 执行count查询
*
* @return
*/
private static long execCountSql(Connection connection, Select select, SqlSignature signature, String originalSql, List sqlArgs) throws SQLException {
String countSql;
SqlAndParamIndexPair pair = optimizeSql(select, originalSql, true, true, true, true);
countSql = "select count(*) from(\n" + pair.sql + "\n) as _cot";
if (logger.isDebugEnabled()) {
LogHelper.logSql(logger, countSql);
LogHelper.logArgs(logger, sqlArgs);
}
try (PreparedStatement stmt = connection.prepareStatement(countSql)) {
for (int i = 0; i < sqlArgs.size(); i++) {
if (pair.indexOfParameterToSkip.contains(i + 1)) {
continue;
}
stmt.setObject(i + 1, sqlArgs.get(i));
}
ResultSet resultSet = stmt.executeQuery();
resultSet.next();
return resultSet.getLong(1);
}
}
private static class SqlAndParamIndexPair {
String sql;
SortedSet indexOfParameterToSkip = new TreeSet<>(Comparator.reverseOrder());
}
public static SqlAndParamIndexPair optimizeSql(Select select,
String originalSql,
boolean removeLimit,
boolean removeOffset,
boolean removeOrderBy,
boolean removeForUpdate) {
SqlAndParamIndexPair pair = new SqlAndParamIndexPair();
pair.sql = originalSql;
if (select == null || !(select.getSelectBody() instanceof PlainSelect)) {
return pair;
}
PlainSelect plainSelect = (PlainSelect) select.getSelectBody();
boolean forUpdate = plainSelect.isForUpdate();
Limit limit = plainSelect.getLimit();
Offset offset = plainSelect.getOffset();
List orderByElements = plainSelect.getOrderByElements();
ExpressionVisitorAdapter getParamIndexVisitor = new ExpressionVisitorAdapter() {
@Override
public void visit(JdbcParameter parameter) {
pair.indexOfParameterToSkip.add(parameter.getIndex());
}
};
if (removeForUpdate) {
plainSelect.setForUpdate(false);
}
if (removeLimit && limit != null) {
plainSelect.setLimit(null);
limit.getRowCount().accept(getParamIndexVisitor);
}
if (removeOffset && offset != null) {
plainSelect.setOffset(null);
offset.getOffset().accept(getParamIndexVisitor);
}
if (removeOrderBy && orderByElements != null) {
for (OrderByElement element : orderByElements) {
element.getExpression().accept(getParamIndexVisitor);
}
}
pair.sql = select.toString();
plainSelect.setForUpdate(forUpdate);
plainSelect.setLimit(limit);
plainSelect.setOffset(offset);
plainSelect.setOrderByElements(orderByElements);
return pair;
}
}
