Java PostgreSQL：如何打印结果集？

你好，各位飞越者

如何打印结果集的列，例如“名称”（按编号顺序）

我被困在主方法@//的底部，无法从结果集中打印数据

谢谢你的帮助

import java.sql.*;
import java.util.Scanner;
import java.io.*;

public class Database {

    public static Connection connectToDatabase(String user, String port,
            String database) {
        System.out.println("-------- PostgreSQL JDBC Connection Testing ------------");
        try {
            Class.forName("org.postgresql.Driver");
        } catch (ClassNotFoundException e) {

            System.out.println("Where is your PostgreSQL JDBC Driver? " + "Include in your library path!");
            e.printStackTrace();
        }
        System.out.println("PostgreSQL JDBC Driver Registered!");

        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:postgresql://localhost:" + port + "/" + database, user, "doesn't matter!");
        } catch (SQLException e) {
            System.out.println("Connection Failed! Check output console");
            e.printStackTrace();
        }
        return connection;
    }

    public static ResultSet executeSelect(Connection connection, String query) {
        Statement st = null;
        try {
            st = connection.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }

        ResultSet rs = null;
        try {
            rs = st.executeQuery(query);
            //st.close();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }

        return rs;
    }

    public static void dropTable(Connection connection, String table) {
        Statement st = null;
        try {
            st = connection.createStatement();
            st.execute("DROP TABLE " + table);
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void createTable(Connection connection,
            String tableDescription) {
        Statement st = null;
        try {
            st = connection.createStatement();
            st.execute("CREATE TABLE " + tableDescription);
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static int insertIntoTableFromFile(Connection connection,
            String table, String file) {

        BufferedReader br = null;
        int numRows = 0;
        try {
            Statement st = connection.createStatement();
            String sCurrentLine, brokenLine[], composedLine = "";
            br = new BufferedReader(new FileReader("src/TopURLs"));

            while ((sCurrentLine = br.readLine()) != null) {
                // Insert each line to the DB
                brokenLine = sCurrentLine.split("\t");
                composedLine = "INSERT INTO dotcom VALUES (";
                int i;
                for (i = 0; i < brokenLine.length - 1; i++) {
                    composedLine += "'" + brokenLine[i] + "',";
                }
                composedLine += "'" + brokenLine[i] + "')";
                numRows += st.executeUpdate(composedLine);
                //System.out.println(composedLine);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)
                    br.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return numRows;
    }

    public static void print() {
        System.out.println("########## 1st Query ##########");

    }

    public static void main(String[] argv) throws SQLException {
        /*
        Scanner input = new Scanner(System.in);
        System.out.println("Please enter your Username:");
        String user = input.next();
        System.out.println("Please enter your Port ID:");
        String port = input.next();
        */

        String user = "zbva777";
        String port = "28046";
        String database = "test";

        Connection connection = connectToDatabase(user, port, database);

        if (connection != null) {
            System.out.println("You made it, take control your database now!");
        } else {
            System.out.println("Failed to make connection!");
            return;
        }
        // Now we're ready to work on the DB

        // connection is of type Connection (in JDBC)
        DatabaseMetaData dbm = connection.getMetaData();

        // check if table is there
        ResultSet tables = dbm.getTables(null, null, "dotcom", null);
        if (tables.next()) {
            System.out.println("Table exists");
        } else {
            System.out.println("Table does not exist");
        }

        // check if view is there?
        //"create view foo as select * from table;"
        //"select * from foo;"
        ResultSet views = dbm.getTables("catalog name", null, null, null);
        if (views.next()) {
            System.out.println("View exists");
        } else {
            System.out.println("View does not exist");
        }

        String query = "SELECT * FROM dotcom";
        String view = "CREATE VIEW view as SELECT FROM dotcom";
        ResultSet rs = executeSelect(connection, query);
        try {
            while (rs.next()) {
                //System.out.print("Column 1 returned ");
                //System.out.println(rs.getString(1));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }

        dropTable(connection, "dotcom");
        createTable(connection, "dotcom (rank int primary key, name varchar(128), type varchar(128), subtype varchar(128), subsubtype varchar(128));");
        int rows = insertIntoTableFromFile(connection, "dotcom", "src/TopURLs");
        System.out.println(rows + " rows inserted.");

        //Print data from result set
        print();
        while(rs.next()) {
        rs.getInt("rank");
        String name = rs.getString("name");
        System.out.println(name);
        }

        rs.close();
    }
}

import java.sql.*；
导入java.util.Scanner；
导入java.io.*；
公共类数据库{
公共静态连接connectToDatabase（字符串用户、字符串端口、，
字符串（数据库）{
System.out.println（“--PostgreSQL JDBC连接测试------------”；
试一试{
Class.forName（“org.postgresql.Driver”）；
}catch（classnotfounde异常）{
println（“您的PostgreSQL JDBC驱动程序在哪里？”+“包含在您的库路径中！”）；
e、 printStackTrace（）；
}
System.out.println（“PostgreSQL JDBC驱动程序已注册！”）；
连接=空；
试一试{
connection=DriverManager.getConnection（“jdbc:postgresql://localhost:“+端口+”/“+数据库，用户，“没关系！”；
}捕获（SQLE异常）{
System.out.println（“连接失败！检查输出控制台”）；
e、 printStackTrace（）；
}
回路连接；
}
公共静态结果集executeSelect（连接、字符串查询）{
语句st=null；
试一试{
st=connection.createStatement（）；
}捕获（SQLE异常）{
e、 printStackTrace（）；
返回null；
}
结果集rs=null；
试一试{
rs=st.executeQuery（查询）；
//圣克洛斯（）；
}捕获（SQLE异常）{
e、 printStackTrace（）；
返回null；
}
返回rs；
}
公共静态void dropTable（连接、字符串表）{
语句st=null；
试一试{
st=connection.createStatement（）；
st.execute（“升降台”+升降台）；
圣克洛斯（）；
}捕获（SQLE异常）{
e、 printStackTrace（）；
}
}
公共静态void createTable（连接，
字符串表（描述）{
语句st=null；
试一试{
st=connection.createStatement（）；
st.execute（“创建表”+表描述）；
圣克洛斯（）；
}捕获（SQLE异常）{
e、 printStackTrace（）；
}
}
公共静态int insertIntoTableFromFile（连接，
字符串表、字符串文件）{
BufferedReader br=null；
int numRows=0；
试一试{
语句st=connection.createStatement（）；
字符串sCurrentLine，brokenLine[]，composedLine=“”；
br=新的BufferedReader（新的文件读取器（“src/topURL”）；
而（（sCurrentLine=br.readLine（））！=null）{
//将每一行插入数据库
brokenLine=sCurrentLine.split（“\t”）；
composedLine=“插入到互联网价值（”；
int i；
对于（i=0；i