统计一个字符串在另一个字符串中出现的次数（Java mysql)

import java.sql.*; 
import java.util.*; 
public class Indexof{ 


public static void main(String[] args) { 
try{ 
Class.forName("com.mysql.jdbc.Driver").newInstance(); 
String url="jdbc:mysql://localhost:3306/test"; 
String user="root"; 
String password="123"; 


Connection conn= DriverManager.getConnection(url,user,password); 
Statement stmt=conn.createStatement(); 
String sql = "select * from Text";
ResultSet rs=stmt.executeQuery(sql); 


while(rs.next()) { 
//System.out.println(rs.getString("text"));
String str =rs.getString("text");
if (rs.getString("text").indexOf("你好")!=-1)
{
System.out.println("发现");
 String str1 = "你好";
      int count = 0;
int start = 0;
while (str.indexOf(str1, start) >= 0 && start < str.length()) {
count++;
start = str.indexOf(str1, start) + str1.length();
}
System.out.println(str1 + "在" + str + "\n\n出现的次数为:" + count);
}
  
} 
}catch(Exception e){ 
e.printStackTrace(); 
} 
} 
}