Java 从resultset返回字符串

我在从数据库连接返回字符串时遇到问题。它说return_语句“可能尚未初始化”，当然，但如果我将返回点放在try中，它会说“对象中没有返回”。我有点糊涂请不要怪我：/

import java.sql.*;

public  class DbConnector {

   static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
   static final String DB_ADDRESS = "jdbc:mysql://localhost:8889/java_prog";

   String query;

     static final String USER = "root";
     static final String PASS = "root";





  public static String dbAsker (String query){
    Connection conn = null;
    Statement stmt = null;
    String return_statement;

     try{
      //STEP 2: Register JDBC driver
      Class.forName("com.mysql.jdbc.Driver");

      //STEP 3: Open a connection
      System.out.println("Connecting to database...");
      conn = DriverManager.getConnection(DB_ADDRESS,USER,PASS);

      //STEP 4: Execute a query

      ResultSet rs = stmt.executeQuery(query);



     return_statement = rs.toString();

      //STEP 6: Clean-up environment
      rs.close();
       stmt.close();
      conn.close();

   }catch(SQLException se){
      //Handle errors for JDBC
      se.printStackTrace();
   }catch(Exception e){
      //Handle errors for Class.forName
      e.printStackTrace();
   }finally{
      //finally block used to close resources
       try{
         if(stmt!=null)
            stmt.close();
      }catch(SQLException se2){
      }// nothing we can do
      try{
         if(conn!=null)
            conn.close();
      }catch(SQLException se){
         se.printStackTrace();
      }//end finally try
   }//end try
   System.out.println("Goodbye!");

   return return_statement;



  }
} 

---

使用

字符串返回\u语句=null或
字符串返回_语句=”而不是
字符串返回\u语句。若发生异常，则在使用in return时return_语句并没有任何值，这在Java中是不可能的
 试试这个字符串return_statement=“”<代码>语句stmt
未初始化
stmt=conn.createStatement（）丢失可能的副本