首先，我是这个java的新手。这是我的代码：
public class functions {
private static Connection connection;
private static ArrayList<MapModel> list = new ArrayList<MapModel>();
private static Cipher cipher;
public static ArrayList<MapModel> getAllId(String report_type, String dist_code){
ArrayList<MapModel> idList = new ArrayList<MapModel>();
ResultSet rs = null;
Statement statement = null;
try {
connection = DBconnection.getConnection();
System.out.println(connection.getMetaData());
statement = connection.createStatement();
String sproc=null;
sproc="call load_district('" + report_type + "','" + dist_code + "')";
System.out.println("call load_district('" + report_type + "','" + dist_code + "')");
CallableStatement cstmt = connection.prepareCall("{"+sproc+"}");
rs = cstmt.executeQuery();
System.out.println(rs.isClosed());
System.out.println(statement.isClosed());
System.out.println(connection.isClosed());
if (!rs.isBeforeFirst()) {
System.out.println("no data");
} else {
while (rs.next()) {
//some data
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
// just to check
System.out.println("m closing all");
System.out.println(rs.isClosed());
System.out.println(statement.isClosed());
System.out.println(connection.isClosed());
// ---end---
DbUtils.closeQuietly(statement);
DbUtils.closeQuietly(rs);
DbUtils.closeQuietly(connection);
} catch (SQLException ex) {
Logger.getLogger(functions.class.getName()).log(Level.SEVERE, null, ex);
}
}
return idList;
}
}
并非总是如此，但有时我会收到此错误：
Info: call load_district('someval','someval')
Info: false
Info: true
Info: true
Info: m closing all
Info: true
Info: true
Info: true
Severe: java.sql.SQLException: Operation not allowed after ResultSet closed
我不明白为什么语句和连接在关闭之前处于关闭状态。