如何使用springtask定时去获取数据库的表,字段以及注释

如何使用springtask定时去获取数据库的表,字段以及注释

1. 获取数据库中的表,字段以及注释工具类

package com.hw.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

/**
 * @author hw
 * @version 1.0
 * @date 2020/3/24 21:14
 */
@Component
public class DataBaseUtil {

    private final static Logger LOGGER = LoggerFactory.getLogger(DataBaseUtil.class);

    private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/test_wechat?useUnicode=true&characterEncoding=utf8";
    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) {
            LOGGER.error("can not load jdbc driver", e);
        }
    }

    /**
     * 获取数据库连接
     *
     * @return
     */
    public static Connection getConnection() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (SQLException e) {
            LOGGER.error("get connection failure", e);
        }
        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) {
                LOGGER.error("close connection failure", e);
            }
        }
    }

    /**
     * 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) {
            LOGGER.error("getTableNames failure", e);
        } finally {
            try {
                rs.close();
                closeConnection(conn);
            } catch (SQLException e) {
                LOGGER.error("close ResultSet failure", e);
            }
        }
        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 = conn.prepareStatement(tableSql);
            //结果集元数据
            ResultSetMetaData rsmd = 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) {
            LOGGER.error("getColumnNames failure", e);
        } finally {
            if (pStemt != null) {
                try {
                    pStemt.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                    LOGGER.error("getColumnNames close pstem and connection failure", e);
                }
            }
        }
        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 = conn.prepareStatement(tableSql);
            //结果集元数据
            ResultSetMetaData rsmd = 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) {
            LOGGER.error("getColumnTypes failure", e);
        } finally {
            if (pStemt != null) {
                try {
                    pStemt.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                    LOGGER.error("getColumnTypes close pstem and connection failure", e);
                }
            }
        }
        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 = conn.prepareStatement(tableSql);
            rs = pStemt.executeQuery("show full columns from " + tableName);
            while (rs.next()) {
                columnComments.add(rs.getString("Comment"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                    closeConnection(conn);
                } catch (SQLException e) {
                    LOGGER.error("getColumnComments close ResultSet and connection failure", e);
                }
            }
        }
        return columnComments;
    }

    public static void main(String[] args) {
        List<String> tableNames = getTableNames();
        System.out.println("tableNames:" + tableNames);
        for (String tableName : tableNames) {
            System.out.println("ColumnNames:" + getColumnNames(tableName));
//            System.out.println("ColumnTypes:" + getColumnTypes(tableName));
//            System.out.println("ColumnComments:" + getColumnComments(tableName));
        }
    }
}

2. 启动类中添加可支持springtask注解

package com;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

/**
 * @author hw
 * @version 1.0
 * @date 2020/3/24 20:04
 */
@SpringBootApplication
@EnableScheduling
public class SpringTestProjectApplication {

    public static void main(String[] args) {
        System.out.println(SpringApplication.run(SpringTestProjectApplication.class,args));
    }
}

3. 获取数据并返回

package com.hw;

import com.google.gson.JsonObject;
import com.hw.util.DataBaseUtil;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.List;

/**
 * @author hw
 * @version 1.0
 * @date 2020/3/24 19:57
 */
@Controller
public class FindAll {

    @RequestMapping("/findAll")
    @ResponseBody
    @Scheduled(cron = "0/1 * *  * * ? ")
    public List<String> TestDemo(){
        List<String> list = new ArrayList<>();
        List<String> tableNames = DataBaseUtil.getTableNames();
        for (String tableName : tableNames){
            List<String> columnNames = DataBaseUtil.getColumnNames(tableName);
            for (String columnName : columnNames){
                list.add(columnName);
            }
        }
        System.out.println(list);
        return list;
    }
}