/** 
 * @说明 执行一条查询SQL语句，可以带参数 
 */ 
public static List excuteQuery(String sql, Object[] objs) { 
  Connection conn = null; 
  PreparedStatement psta = null; 
  ResultSet rs = null; 
  List iResult = null; 
  Object[] objArr = null; 
  try { 
    conn = getConn(); // 得到链接 
    PreparedStatement state = conn.prepareStatement(sql); 
    if(null != objs){ 
      for (int i = 0; i < objs.length; i++) { 
        state.setObject(i + 1, objs[i]); 
      } 
    } 
    ResultSet resultSet = state.executeQuery(); // 执行查询，返回结果接集合 
    iResult = new ArrayList(); 
    int count = resultSet.getMetaData().getColumnCount(); // 一共有多少列数据 
    while (resultSet.next()) { 
      objArr = new Object[count]; 
      for (int i = 1; i <= count; i++) { 
        objArr[i - 1] = resultSet.getObject(i); // 增加到返回的集合中 
      } 
      iResult.add(objArr); 
    } 
  } catch (Exception e) { 
    e.printStackTrace(); 
    iResult = null; 
  } finally { 
    try { 
      if (rs != null) { 
        rs.close(); 
      } 
      if (psta != null) { 
        psta.close(); 
      } 
      if (conn != null) { 
        conn.close(); 
      } 
    } catch (Exception e2) { 
 
    } 
  } 
  return iResult; 
} 

后来我输入这样的一个参数进行查询：

public static void main(String[] args) { 
  Object[] para = new Object[]{"c"}; 
  List list = excuteQuery("select * from s_user t where t.userName like '%?%'",para);    
  for (Object[] o : list) { 
    for (Object ob : o) { 
      System.out.print(ob + "-"); 
    } 
    System.out.println(); 
  } 
} 

结果报错如下：

java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0). 
  at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1056) 
  at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957) 
  at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927) 
  at com.mysql.jdbc.PreparedStatement.checkBounds(PreparedStatement.java:3279) 
  at com.mysql.jdbc.PreparedStatement.setInternal(PreparedStatement.java:3263) 
  at com.mysql.jdbc.PreparedStatement.setString(PreparedStatement.java:4087) 
  at com.mysql.jdbc.PreparedStatement.setObject(PreparedStatement.java:3513) 
  at org.apache.commons.dbcp.DelegatingPreparedStatement.setObject(DelegatingPreparedStatement.java:166) 
  at com.nms.common.db.ConnectionManager.excuteQuery(ConnectionManager.java:86) 
  at com.nms.common.db.ConnectionManager.main(ConnectionManager.java:20) 
Exception in thread "main" java.lang.NullPointerException 
  at com.nms.common.db.ConnectionManager.main(ConnectionManager.java:21) 

后来才知道，模糊查询时要这样写：

public static void main(String[] args) { 
  Object[] para = new Object[]{"%c%"}; 
  List list = excuteQuery("select * from s_user t where t.userName like ?",para);    
  for (Object[] o : list) { 
    for (Object ob : o) { 
      System.out.print(ob + "-"); 
    } 
    System.out.println(); 
  } 
}