比如我傳給rs一條SQL語句，"select * from TableName" ，我想得到TableName的字段名，這樣我就可以把一條結果保存到HashTable里，整個結果同樣可以放到HashList里，方便jsp頁面上的JSTL取值，最好付上整個DB代碼內容，謝謝
2 回答
慕姐8265434
TA貢獻1813條經驗 獲得超2個贊
import java.sql.*;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;public class Test{ public static void main(String[] args) throws Exception {
// 驅動
String driver = "com.mysql.jdbc.Driver";
// 數據庫連接
String url = "jdbc:mysql://localhost:3306/test";
// 用戶名
String user = "root";
// 數據庫密碼
String password = "admin";
// 加載驅動
Class.forName(driver);
// 獲取鏈接
Connection connection = DriverManager
.getConnection(url, user, password);
// 創建查詢聲明
PreparedStatement preparedStatement = connection
.prepareStatement("select * from dept");
// 獲取結果
ResultSet resultSet = preparedStatement.executeQuery();
// 獲取各個列的信息
ResultSetMetaData metaData = resultSet.getMetaData();
// 一條數據保存在一個Hashtable 將所有Hashtable存放到list
List<Hashtable<String, Object>> rows = new ArrayList<Hashtable<String, Object>>();
while (resultSet.next()) {
Hashtable<String, Object> row = new Hashtable<String, Object>();
for (int i = 1; i <= metaData.getColumnCount(); i++) {
// 打印列名
System.out.println(metaData.getColumnName(i));
row.put(metaData.getColumnName(i), resultSet.getObject(i));
}
rows.add(row);
}
resultSet.close();
preparedStatement.close();
connection.close();
}}
MMMHUHU
TA貢獻1834條經驗 獲得超8個贊
參考如下例子，利用jdbc獲取到結果集后，利用ResultSetMetaData的方法就可以取到字段名了！
package com.javacodegeeks.snippets.core;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
public class RetrieveColumnNamesExample {
public static void main(String[] args) {
Connection connection = null;
try {
// 加載jdbc驅動
String driverName = "com.mysql.jdbc.Driver";
Class.forName(driverName);
//創建連接
String serverName = "localhost";
String schema = "test";
String url = "jdbc:mysql://" + serverName + "/" + schema;
String username = "username";
String password = "password";
connection = DriverManager.getConnection(url, username, password);
System.out.println("Successfully Connected to the database!");
} catch (ClassNotFoundException e) {
System.out.println("Could not find the database driver " + e.getMessage());
} catch (SQLException e) {
System.out.println("Could not connect to the database " + e.getMessage());
}
try {
// 創建結果集
Statement statement = connection.createStatement();
ResultSet results = statement.executeQuery("SELECT * FROM test_table");
// 獲取 metadata
ResultSetMetaData metadata = results.getMetaData();
// 從 metadata中獲取列的個數
int columnCount = metadata.getColumnCount();
System.out.println("test_table columns : ");
//循環獲取列的名字并打印
for (int i=1; i<=columnCount; i++) {
String columnName = metadata.getColumnName(i);
System.out.println(columnName);
}
} catch (SQLException e) {
System.out.println("Could not retrieve database metadata " + e.getMessage());
}
}
}
其中以下的重點代碼片段：
ResultSet results = statement.executeQuery("SELECT * FROM test_table");
// 獲取 metadata
ResultSetMetaData metadata = results.getMetaData();
// 從 metadata中獲取列的個數
int columnCount = metadata.getColumnCount();
System.out.println("test_table columns : ");
//循環獲取列的名字并打印
for (int i=1; i<=columnCount; i++) {
String columnName = metadata.getColumnName(i);
System.out.println(columnName);
}
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