Java获取数据库信息

import java.sql.*;
import java.util.*;
 
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
import com.mysql.jdbc.ResultSetMetaData;
 
public class test {
	private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/world?useUnicode=true&characterEncoding=utf-8";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "root";
    private static final String SQL = "SELECT * FROM ";// 数据库操作
 
     static {
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
        }
    }
 
    /**
     * 获取数据库连接
     *
     * @return
     */
    public static Connection getConnection() {
        Connection conn = null;
		try {
			conn = (Connection) DriverManager.getConnection(URL, USERNAME, PASSWORD);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        return conn;
    }
 
    /**
     * 关闭数据库连接
     * @param conn
     */
    public static void closeConnection(Connection conn) {
        if(conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
            	e.printStackTrace();
            }
        }
    }
 
    /**
     * 获取数据库下的所有表名
     */
    public static List<String> getTableNames() {
        List<String> tableNames = new ArrayList<>();
        Connection conn = getConnection();
        ResultSet rs = null;
        try {
            //获取数据库的元数据
            DatabaseMetaData db = conn.getMetaData();
            //从元数据中获取到所有的表名
            rs = db.getTables(null, null, null, new String[] { "TABLE" });
            while(rs.next()) {
                tableNames.add(rs.getString(3));
            }
        } catch (SQLException e) {
        	e.printStackTrace();
        } finally {
            try {
                rs.close();
                closeConnection(conn);
            } catch (SQLException e) {
            	e.printStackTrace();
            }
        }
        return tableNames;
    }
 
    /**
     * 获取表中所有字段名称
     * @param tableName 表名
     * @return
     */
    public static List<String> getColumnNames(String tableName) {
        List<String> columnNames = new ArrayList<>();
        //与数据库的连接
        Connection conn = getConnection();
        PreparedStatement pStemt = null;
        String tableSql = SQL + tableName;
        try {
            pStemt = (PreparedStatement) conn.prepareStatement(tableSql);
            //结果集元数据
            ResultSetMetaData rsmd = (ResultSetMetaData) pStemt.getMetaData();
            //表列数
            int size = rsmd.getColumnCount();
            for (int i = 0; i < size; i++) {
                columnNames.add(rsmd.getColumnName(i + 1));
            }
        } catch (SQLException e) {
        	e.printStackTrace();
        } finally {
            if (pStemt != null) {
                try {
                    pStemt.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                	e.printStackTrace();
                }
            }
        }
        return columnNames;
    }
 
    /**
     * 获取表中所有字段类型
     * @param tableName
     * @return
     */
    public static List<String> getColumnTypes(String tableName) {
        List<String> columnTypes = new ArrayList<>();
        //与数据库的连接
        Connection conn = getConnection();
        PreparedStatement pStemt = null;
        String tableSql = SQL + tableName;
        try {
            pStemt = (PreparedStatement) conn.prepareStatement(tableSql);
            //结果集元数据
            ResultSetMetaData rsmd = (ResultSetMetaData) pStemt.getMetaData();
            //表列数
            int size = rsmd.getColumnCount();
            for (int i = 0; i < size; i++) {
                columnTypes.add(rsmd.getColumnTypeName(i + 1));
            }
        } catch (SQLException e) {
        	e.printStackTrace();
        } finally {
            if (pStemt != null) {
                try {
                    pStemt.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                	e.printStackTrace();
                }
            }
        }
        return columnTypes;
    }
 
    /**
     * 获取表中字段的所有注释
     * @param tableName
     * @return
     */
    public static List<String> getColumnComments(String tableName) {
        List<String> columnTypes = new ArrayList<>();
        //与数据库的连接
        Connection conn = getConnection();
        PreparedStatement pStemt = null;
        String tableSql = SQL + tableName;
        List<String> columnComments = new ArrayList<>();//列名注释集合
        ResultSet rs = null;
        try {
            pStemt = (PreparedStatement) conn.prepareStatement(tableSql);
            rs = pStemt.executeQuery("show full columns from " + tableName);
            while (rs.next()) {
                columnComments.add(rs.getString("Comment"));
            }
        } catch (SQLException e) {
        	e.printStackTrace();
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                	e.printStackTrace();
                }
            }
        }
        return columnComments;
    }
}
 

参考链接：
https://www.jb51.net/article/121530.htm