Java中自动生成实体类

Q1：实体层（vo）

package com;

import java.io.File; 
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.util.ArrayList;
import java.util.List;

/**
 * 根据数据库表结构 自动生成java Bean
 * 
 * @author DLHT 2016年3月4日下午5:00:28 AutoCreateClass.java DLHT
 */
public class AutoCreateBean {

    /*//  sqlserver 驱动类
    private static final String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
    //  数据库登录用户名
    private static final String USER = "sa";//数据库中的账号
    //  数据库登录密码
    private static final String PASSWORD = "";//数据库中的密码
    // 数据库连接地址
    private static final String URL = "jdbc:sqlserver://localhost:1433;databasename=TakeawayDB";*/
　　//mysql驱动类
    private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/schooldb?serverTimezone=GMT%2B8";
    private static final String USER = "root";//数据库中的账号
    private static final String PASSWORD = "";//数据库中的密码
    private static String tablename;

    private String[] colnames; // 列名数组

    private String[] colTypes; // 列名类型数组

    private int[] colSizes; // 列名大小数组

    private boolean f_util = false; // 是否需要导入包java.util.*

    private boolean f_sql = false; // 是否需要导入包java.sql.*

    /**
     * 获取指定数据库中包含的表 TBlist
     * 
     * @time 2016年3月4日下午5:54:52
     * @packageName com.util
     * @return 返回所有表名(将表名放到一个集合中)
     * @throws Exception
     */
    public List<String> TBlist() throws Exception {
        // 访问数据库 采用 JDBC方式
        Class.forName(DRIVER);

        Connection con = DriverManager.getConnection(URL, USER, PASSWORD);

        DatabaseMetaData md = con.getMetaData();

        List<String> list = null;
        //注意这是特别需要注意的点
        ResultSet rs = md.getTables(con.getCatalog(), null, "%", null);//mysql需要用到的
        //ResultSet rs = md.getTables(null, null, null, null);//sqlserver需要用到的
        if (rs != null) {
            list = new ArrayList<String>();
        }
        while (rs.next()) {
            //System.out.println("|表" + (i++) + ":" + rs.getString("TABLE_NAME"));
            String tableName = rs.getString("TABLE_NAME");
            list.add(tableName);
        }
        rs = null;
        md = null;
        con = null;
        return list;
    }

    public void GenEntity(List<String> TBlist, String packageName)throws Exception {
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSetMetaData rsmd = null;

        // 访问数据库 采用 JDBC方式
        Class.forName(DRIVER);
        conn = DriverManager.getConnection(URL, USER, PASSWORD);

        for (int k = 0; k < TBlist.size(); k++) {
            tablename = TBlist.get(k);
            String strsql = "select * from " + tablename;
            pstmt = conn.prepareStatement(strsql);
            rsmd = pstmt.getMetaData();
            int size = rsmd.getColumnCount();
            // 共有多少列
            colnames = new String[size];
            colTypes = new String[size];
            colSizes = new int[size];
            for (int i = 0; i < rsmd.getColumnCount(); i++) {
                colnames[i] = rsmd.getColumnName(i + 1);
                colTypes[i] = rsmd.getColumnTypeName(i + 1);
                if (colTypes[i].equalsIgnoreCase("datetime")) {
                    f_util = true;
                }
                if (colTypes[i].equalsIgnoreCase("image")
                        || colTypes[i].equalsIgnoreCase("text")) {
                    f_sql = true;
                }
                colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
            }
            markerBean(initcap(tablename), parse(), packageName);
        }
        pstmt = null;
        rsmd = null;
        conn = null;
    }

    /**
     * 解析处理(生成实体类主体代码)
     */
    private String parse() {
        StringBuffer sb = new StringBuffer();
        if (f_util) {
            sb.append("import java.util.Date;
");
        }
        if (f_sql) {
            sb.append("import java.sql.*;


");
        }
        sb.append("public class " + initcap(tablename) + " {
");
        processAllAttrs(sb);
        processConstructor(sb,initcap(tablename));
        processAllMethod(sb);
        sb.append("}
");

        return sb.toString();

    }

    /**
     * 创建java 文件 将生成的属性 get/set 方法 保存到 文件中 markerBean
     * 
     * @time 2015年9月29日下午4:15:22
     * @packageName fanshe
     * @param className
     *            类名称
     * @param content
     *            类内容 包括属性 getset 方法
     */
    public void markerBean(String className, String content, String packageName) {
        String folder = System.getProperty("user.dir") + "/src/" + packageName + "/";

        File file = new File(folder);
        if (!file.exists()) {
            file.mkdirs();
        }
        String fileName = folder + className + ".java";

        try {
            File newdao = new File(fileName);
            FileWriter fw = new FileWriter(newdao);
            fw.write("package	" + packageName.replace("/", ".") + ";
");
            fw.write(content);
            fw.flush();
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 生成所有的方法
     * 
     * @param sb
     */
    private void processAllMethod(StringBuffer sb) {
        for (int i = 0; i < colnames.length; i++) {
            sb.append("	public void set" + initcap(colnames[i]) + "("
                    + sqlType2JavaType(colTypes[i]) + " " + colnames[i]
                    + "){
");
            sb.append("		this." + colnames[i] + " = " + colnames[i] + ";
");
            sb.append("	}
");

            sb.append("	public " + sqlType2JavaType(colTypes[i]) + " get"
                    + initcap(colnames[i]) + "(){
");
            sb.append("		return " + colnames[i] + ";
");
            sb.append("	}
");
        }
        
    }

    /**
     * 解析输出属性
     * 
     * @return
     */
    private void processAllAttrs(StringBuffer sb) {
        for (int i = 0; i < colnames.length; i++) {
            sb.append("	private " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";
");
        }
    }
    /**
     * 解析生成构造函数
     * 
     * @return
     */
    private void processConstructor(StringBuffer sb,String tableName) {
        sb.append("	public "+tableName+"(){}
");
        sb.append("	public "+tableName+"(");
        String link="";
        for (int i = 0; i < colnames.length; i++) {
            sb.append(link + sqlType2JavaType(colTypes[i]) + " " + colnames[i] );
            link=",";
        }
        sb.append("){
");
        for (int i = 0; i < colnames.length; i++) {
            sb.append("		this."+colnames[i]+"="+colnames[i]+";
");
        }
        sb.append("	}
");
    }

    /**
     * 把输入字符串的首字母改成大写
     * 
     * @param str
     * @return
     */
    private String initcap(String str) {
        char[] ch = str.toCharArray();
        if (ch[0] >= 'a' && ch[0] <= 'z') {
            ch[0] = (char) (ch[0] - 32);
        }
        return new String(ch);
    }

    private String sqlType2JavaType(String sqlType) {
        if (sqlType.equalsIgnoreCase("bit")) {
            return "boolean";
        } else if (sqlType.equalsIgnoreCase("tinyint")) {
            return "byte";
        } else if (sqlType.equalsIgnoreCase("smallint")) {
            return "short";
        } else if (sqlType.equalsIgnoreCase("int")) {
            return "int";
        } else if (sqlType.equalsIgnoreCase("bigint")) {
            return "long";
        } else if (sqlType.equalsIgnoreCase("float")) {
            return "float";
        } else if (sqlType.equalsIgnoreCase("decimal")
                || sqlType.equalsIgnoreCase("numeric")
                || sqlType.equalsIgnoreCase("real")) {
            return "double";
        } else if (sqlType.equalsIgnoreCase("money")
                || sqlType.equalsIgnoreCase("smallmoney")) {
            return "double";
        } else if (sqlType.equalsIgnoreCase("varchar")
                || sqlType.equalsIgnoreCase("char")
                || sqlType.equalsIgnoreCase("nvarchar")
                || sqlType.equalsIgnoreCase("nchar")
                || sqlType.equalsIgnoreCase("uniqueidentifier")
                || sqlType.equalsIgnoreCase("ntext")) {
            return "String";
        } else if (sqlType.equalsIgnoreCase("datetime")
                ||sqlType.equalsIgnoreCase("date")){
            return "Date";
        }

        else if (sqlType.equalsIgnoreCase("image")) {
            return "Blob";
        } else if (sqlType.equalsIgnoreCase("text")) {
            return "Clob";
        }
        return "String";
    }

    public static void main(String[] args) throws Exception {
        AutoCreateBean auto = new AutoCreateBean();
        List<String> list = auto.TBlist();
　　　　　//注意，这点也特别需要注意，com/vo是包名
        auto.GenEntity(list, "com/vo");
    }

}

提示：一些需要注意的地方已经特别提示了，只需要照做，因该就没问题了。

Q2：数据访问层（dao）

package com;

import java.io.File; 
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.*;

/**
 * 根据数据库表结构 自动生成java MVC中的dao
 * 
 * @author DLHT 2018年5月10日下午15:00:28 AutoCreateDao.java 
 */
public class AutoCreateDao {

    /*//  sql 驱动类
    private static final String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";

    //  数据库登录用户名
    private static final String USER = "";

    //  数据库登录密码
    private static final String PASSWORD = "";

    // 数据库连接地址
    private static final String URL = "jdbc:sqlserver://localhost:1433;databasename=TakeawayDB";*/
    public static String DRIVER = "com.mysql.jdbc.Driver";
    public static String URL = "jdbc:mysql://localhost:3306/schooldb?serverTimezone=GMT%2B8";
    public static String USER = "root";
    public static String PASSWORD = "";
    private static String tablename;

    private String[] colnames; // 列名数组

    private String[] colTypes; // 列名类型数组

    private int[] colSizes; // 列名大小数组

    /**
     * 获取指定数据库中包含的表 TBlist
     * 
     * @time 2016年3月4日下午5:54:52
     * @packageName com.util
     * @return 返回所有表名(将表名放到一个集合中)
     * @throws Exception
     */
    public List<String> TBlist() throws Exception {
        // 访问数据库 采用 JDBC方式
        Class.forName(DRIVER);

        Connection con = DriverManager.getConnection(URL, USER, PASSWORD);

        DatabaseMetaData md = con.getMetaData();

        List<String> list = null;

        ResultSet rs = md.getTables(null, null, "teacher", null);
        if (rs != null) {
            list = new ArrayList<String>();
        }
        while (rs.next()) {
//            System.out.println("|表" + (i++) + ":" + rs.getString("TABLE_NAME"));
            String tableName = rs.getString("TABLE_NAME");
            list.add(tableName);
        }
        rs = null;
        md = null;
        con = null;
        return list;
    }

    public void GenEntity(List<String> TBlist, String packageName)throws Exception {
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSetMetaData rsmd = null;

        // 访问数据库 采用 JDBC方式
        Class.forName(DRIVER);
        conn = DriverManager.getConnection(URL, USER, PASSWORD);

        for (int k = 0; k < TBlist.size(); k++) {
            tablename = TBlist.get(k);
            String strsql = "select * from " + tablename;
            pstmt = conn.prepareStatement(strsql);
            rsmd = pstmt.getMetaData();
            int size = rsmd.getColumnCount();
            // 共有多少列
            colnames = new String[size];
            colTypes = new String[size];
            colSizes = new int[size];
            for (int i = 0; i < rsmd.getColumnCount(); i++) {
                colnames[i] = rsmd.getColumnName(i + 1);
                colTypes[i] = rsmd.getColumnTypeName(i + 1);
                /*
                if (colTypes[i].equalsIgnoreCase("datetime")) {
                    f_util = true;
                }
                if (colTypes[i].equalsIgnoreCase("image")
                        || colTypes[i].equalsIgnoreCase("text")) {
                    f_sql = true;
                }*/
                colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
            }
            markerBean(initcap(tablename), parse(), packageName);
        }
        pstmt = null;
        rsmd = null;
        conn = null;
    }

    /**
     * 
     * 解析处理(生成实体类主体代码)
     */
    private String parse() {
        StringBuffer sb = new StringBuffer();
        //导入包
        sb.append("import java.sql.*;
");
        sb.append("import java.util.*;
");
        //自己新加一个导入包
        sb.append("import util.DBUtil;
");
        //自己新加一个时间导入包
        sb.append("import java.sql.Date;
");
        //导入对应实体包
        sb.append("import com.vo." + initcap(tablename) + ";
");
        
        sb.append("public class " + initcap(tablename) + "DAO {
");
        processAllMethod(sb);
        sb.append("}
");

        return sb.toString();

    }

    /**
     * 创建java 文件 将生成的属性 get/set 方法 保存到 文件中 markerBean
     * 
     * @time 2015年9月29日下午4:15:22
     * @packageName fanshe
     * @param className
     *            类名称
     * @param content
     *            类内容 包括属性 getset 方法
     */
    public void markerBean(String className, String content, String packageName) {
        String folder = System.getProperty("user.dir") + "/src/" + packageName + "/";

        File file = new File(folder);
        if (!file.exists()) {
            file.mkdirs();
        }
        String fileName = folder + className + "DAO.java";

        try {
            File newdao = new File(fileName);
            FileWriter fw = new FileWriter(newdao);
            fw.write("package	" + packageName.replace("/", ".") + ";
");
            fw.write(content);
            fw.flush();
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 生成所有的方法
     * 
     * @param sb
     */
    private void processAllMethod(StringBuffer sb) {
        /*生成五个方法：
         * findById,findAll,insert,update,delete
        */
        //getModel
        sb.append("	public List<" + initcap(tablename) + "> getModel("+sqlType2JavaType(colTypes[0])+" "+colnames[0]+") {
");
        sb.append("		String sql = "select * from " + tablename + " where "+colnames[0]+"=?";
");
        sb.append("		Object[] in = {"+colnames[0]+"};
");
        sb.append("		ResultSet rs = DBUtil.executeQuery(sql, in);
");
        sb.append("		List<" + initcap(tablename) + "> list = new ArrayList<" + initcap(tablename) + ">();
");
        sb.append("		" + initcap(tablename) + " model = null;
");
        sb.append("		try {
");
        sb.append("			if(rs.next()) {
");
        sb.append("				model = new " + initcap(tablename) + "(
");
        String link="";
        for (int i = 0; i < colnames.length; i++) {
            sb.append(link+"					rs.get" + sqlTypeJavaType(colTypes[i]) + "("" + colnames[i] + "")"); 
            link=",
";
        }
        sb.append(");
");
        sb.append("				list.add(model);
");
        sb.append("			}
");
        sb.append("			DBUtil.close();
");
        sb.append("		} catch (SQLException e) {
");
        sb.append("			e.printStackTrace();
");
        sb.append("		}
");
        sb.append("		return list;
");
        sb.append("	}
");  

        //getModels
        sb.append("	public List<" + initcap(tablename) + "> getModels() {
");
        sb.append("		String sql = "select * from " + tablename + "";
");
        sb.append("		ResultSet rs = DBUtil.executeQuery(sql);
");
        sb.append("		List<" + initcap(tablename) + "> list = new ArrayList<" + initcap(tablename) + ">();
");
        sb.append("		" + initcap(tablename) + " model = null;
");
        sb.append("		try {
");
        sb.append("			while(rs.next()) {
");
        sb.append("				model = new " + initcap(tablename) + "(
");
        
        link="";
        for (int i = 0; i < colnames.length; i++) {
            sb.append(link+"					rs.get" + sqlTypeJavaType(colTypes[i]) + "("" + colnames[i] + "")"); 
            link=",
";
        }
        sb.append(");
");
        sb.append("				list.add(model);
");
        sb.append("			}
");
        sb.append("			DBUtil.close();
");
        sb.append("		} catch (SQLException e) {
");
        sb.append("			e.printStackTrace();
");
        sb.append("		}
");
        sb.append("		return list;
");
        sb.append("	}
"); 

        /*//insert
        sb.append("	public int insert(" + initcap(tablename) + " model) {
");
        //添加相同个数的？
        String linkinsert="";
        for (int i = 1; i < colnames.length; i++) {
            linkinsert+="?"; 
            if(i<colnames.length-1) {
                linkinsert+=",";
            }
        }
        sb.append("		String sql = "insert into " + tablename + " values("+linkinsert+") ";
");
        sb.append("		Object[] in = {");
        link="";
        for (int i = 1; i < colnames.length; i++) {
            sb.append(link+"model.get"+initcap(colnames[i])+"()"); 
            link=",";
        }        
        sb.append("};
");
        //DBUtil...改成自己项目的util
        sb.append("		return DBUtil.executeUpdate(sql, in);
");
        sb.append("	}
"); */
        
        
        //insert
        String linkinserttop="";
        for (int i = 1; i <colnames.length ; i++) {//调用类型，使其进行改变
            linkinserttop+=sqlType2JavaType(colTypes[i])+" "+colnames[i];
            if(i<colnames.length-1) {
                linkinserttop+=",";
            }
        }
        sb.append("	public int insert(" + linkinserttop + ") {
");
        //添加相同个数的？
        String linkinsert="";
        for (int i = 1; i < colnames.length; i++) {
            linkinsert+="?"; 
            if(i<colnames.length-1) {
                linkinsert+=",";
            }
        }
        sb.append("		String sql = "insert into " + tablename + " values("+linkinsert+")";
");
        sb.append("		Object[] in = {");
        link="";
        for (int i = 1; i < colnames.length; i++) {
            sb.append(link+colnames[i]); 
            link=",";
        }        
        sb.append("};
");
        //DBUtil...改成自己项目的util
        sb.append("		return DBUtil.executeUpdate(sql, in);
");
        sb.append("	}
"); 

        //update
        String linkupdate1="";
        for (int i = colnames.length-1; i >=0 ; i--) {//调用类型，使其进行改变
            linkupdate1+=sqlType2JavaType(colTypes[i])+" "+colnames[i];
            if(i>0) {
                linkupdate1+=",";
            }
        }
        sb.append("	public int update("+linkupdate1+") {
");
        String linkupdate2="set"+" ";
        for (int i = 1; i < colnames.length; i++) {
            linkupdate2+=colnames[i]+"=?";
            if(i<colnames.length-1) {
                linkupdate2+=",";
            }
        }  
        sb.append("		String sql = "update " + tablename + " "+linkupdate2+" where "+colnames[0]+"=?";
");
        sb.append("		Object[] in = {");
        link="";
        for (int i = colnames.length-1; i >=0 ; i--) {
            sb.append(link+colnames[i]);
            if(i>0) {
                link=",";
            }
        }        
        sb.append("};
");
        //DBUtil...改成自己项目的util
        sb.append("		return DBUtil.executeUpdate(sql, in);
");
        sb.append("	}
"); 
        

        //delete
        sb.append("	public int delete("+sqlType2JavaType(colTypes[0])+" "+colnames[0]+") {
");
        sb.append("		String sql = "delete from " + tablename + " where "+colnames[0]+"=?";
");
        sb.append("		Object[] in = {"+colnames[0]+"};
");
        //DBUtil...改成自己项目的util
        sb.append("		return DBUtil.executeUpdate(sql, in);
");
        sb.append("	}
"); 
        
    }

    

    /**
     * 把输入字符串的首字母改成大写
     * 
     * @param str
     * @return
     */
    private String initcap(String str) {
        char[] ch = str.toCharArray();
        if (ch[0] >= 'a' && ch[0] <= 'z') {
            ch[0] = (char) (ch[0] - 32);
        }
        return new String(ch);
    }

    private String sqlType2JavaType(String sqlType) {
        if (sqlType.equalsIgnoreCase("bit")) {
            return "boolean";
        } else if (sqlType.equalsIgnoreCase("tinyint")) {
            return "byte";
        } else if (sqlType.equalsIgnoreCase("smallint")) {
            return "short";
        } else if (sqlType.equalsIgnoreCase("int")) {
            return "int";
        } else if (sqlType.equalsIgnoreCase("bigint")) {
            return "long";
        } else if (sqlType.equalsIgnoreCase("float")) {
            return "float";
        } else if (sqlType.equalsIgnoreCase("decimal")
                || sqlType.equalsIgnoreCase("numeric")
                || sqlType.equalsIgnoreCase("real")) {
            return "double";
        } else if (sqlType.equalsIgnoreCase("money")
                || sqlType.equalsIgnoreCase("smallmoney")) {
            return "double";
        } else if (sqlType.equalsIgnoreCase("varchar")
                || sqlType.equalsIgnoreCase("char")
                || sqlType.equalsIgnoreCase("nvarchar")
                || sqlType.equalsIgnoreCase("nchar")
                || sqlType.equalsIgnoreCase("uniqueidentifier")
                || sqlType.equalsIgnoreCase("ntext")) {
            return "String";
        } else if (sqlType.equalsIgnoreCase("datetime")
                ||sqlType.equalsIgnoreCase("date")){
            return "Date";
        }

        else if (sqlType.equalsIgnoreCase("image")) {
            return "Blob";
        } else if (sqlType.equalsIgnoreCase("text")) {
            return "Clob";
        }
        return "String";
    }
    

    private String sqlTypeJavaType(String sqlType) {
        if (sqlType.equalsIgnoreCase("bit")) {
            return "Boolean";
        } else if (sqlType.equalsIgnoreCase("tinyint")) {
            return "Byte";
        } else if (sqlType.equalsIgnoreCase("smallint")) {
            return "Short";
        } else if (sqlType.equalsIgnoreCase("int")) {
            return "Int";
        } else if (sqlType.equalsIgnoreCase("bigint")) {
            return "Long";
        } else if (sqlType.equalsIgnoreCase("float")) {
            return "Float";
        } else if (sqlType.equalsIgnoreCase("decimal")
                || sqlType.equalsIgnoreCase("numeric")
                || sqlType.equalsIgnoreCase("real")) {
            return "Double";
        } else if (sqlType.equalsIgnoreCase("money")
                || sqlType.equalsIgnoreCase("smallmoney")) {
            return "Double";
        } else if (sqlType.equalsIgnoreCase("varchar")
                || sqlType.equalsIgnoreCase("char")
                || sqlType.equalsIgnoreCase("nvarchar")
                || sqlType.equalsIgnoreCase("nchar")
                || sqlType.equalsIgnoreCase("uniqueidentifier")
                || sqlType.equalsIgnoreCase("ntext")) {
            return "String";
        } else if (sqlType.equalsIgnoreCase("datetime")
                ||sqlType.equalsIgnoreCase("date")){
            return "Date";
        }

        else if (sqlType.equalsIgnoreCase("image")) {
            return "Blob";
        } else if (sqlType.equalsIgnoreCase("text")) {
            return "Clob";
        }
        return "String";
    }

    public static void main(String[] args) throws Exception {
        AutoCreateDao auto = new AutoCreateDao();
        List<String> list = auto.TBlist();
        auto.GenEntity(list, "com/dao");

    }

}

提示：一些需要注意的地方已经特别提示了，只需要照做，因该就没问题了。

Q3:DBUTIL

package util;

import java.io.IOException;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

public class DBUtil {
    //连接对象
    //Statement 命令对象
    //打开连接
    //关闭连接
    //得到一个连接对象
    //查询（有参，无参）
    //修改（有参，无参）
    
    static Connection conn = null;
    static Statement stmt = null;
    //驱动，服务器地址，登录用户名，密码  
    static String DBDRIVER;
    static String DBURL;
    static String DBUSER;
    static String DBPWD;
    
    static {
        //先创建资源文件，扩展名为.properties
        //内容是以：dbuser=sa  格式
        Properties prop = new Properties();//先获取资源对象
        try {
            prop.load(Thread.currentThread().getContextClassLoader().
                    getResourceAsStream("/resources/dbconfig.properties"));
            DBDRIVER = prop.getProperty("DBDRIVER");
            DBURL = prop.getProperty("DBURL");
            DBUSER = prop.getProperty("DBUSER");
            DBPWD = prop.getProperty("DBPWD");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }
    
    //打开连接
    public static void open() {
        //加载驱动
        try {
            Class.forName(DBDRIVER);
            conn=DriverManager.getConnection(DBURL,DBUSER,DBPWD);
            
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
                e.printStackTrace();
        }
    }
    //关闭连接
    public static void close() {
        try {
            if(stmt!=null && stmt.isClosed())
                    stmt.close();
            if(conn!=null && !conn.isClosed())
                conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    } 
    //得到一个连接对象，当用户使用DBUtil无法解决个性问题时
    //可以通过本方法获得连接对象
    public static Connection getConnection() {
        try {
            if(conn==null ||conn.isClosed())
                open();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    
    //executeQuery
    //executeUpdate
    //execute
    //获得查询的数据集
    //不带参数的查询
    //select * from student where name='' and sex=''
    public static ResultSet executeQuery(String sql) {
        try {
            open();//保证连接是成功的
            stmt = conn.createStatement();
            return stmt.executeQuery(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    
    //修改表格内容
    public static int executeUpdate(String sql) {
        int result = 0;
        try {
            open();//保证连接是成功的
            stmt = conn.createStatement();
            result = stmt.executeUpdate(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            close();
        }
        return result;
    }
    //如果执行的查询或存储过程，会返回多个数据集，或多个执行成功记录数
    //可以调用本方法，返回的结果，
    //是一个List<ResultSet>或List<Integer>集合
    public static Object execute(String sql) {
        boolean b=false;
        try {
            open();//保证连接是成功的
            stmt = conn.createStatement();
            b = stmt.execute(sql);        
            //true,执行的是一个查询语句，我们可以得到一个数据集
            //false,执行的是一个修改语句，我们可以得到一个执行成功的记录数
            if(b){
                return stmt.getResultSet();
            }
            else {
                return stmt.getUpdateCount();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if(!b) {
                close();
            }
        }
        return null;
    }
    
    // 
    //select * from student where name=? and sex=?
    //带参数的查询，只有输入参数
    public static ResultSet executeQuery(String sql,Object[] in) {
        try {
            open();//保证连接是成功的
            PreparedStatement pst = conn.prepareStatement(sql);
            for(int i=0;i<in.length;i++)
                pst.setObject(i+1, in[i]);
            stmt = pst;//只是为了关闭命令对象pst
            return pst.executeQuery();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    //带参数修改,只有输入参数
    public static int executeUpdate(String sql,Object[] in) {
        try {
            open();//保证连接是成功的
            PreparedStatement pst = conn.prepareStatement(sql);
            for(int i=0;i<in.length;i++)
                pst.setObject(i+1, in[i]);
            stmt = pst;//只是为了关闭命令对象pst
            return pst.executeUpdate();
        } catch (SQLException e) {
            System.out.println(e.getMessage());
            //e.printStackTrace();
        }finally {
            close();
        }
        return 0;
    }
    public static Object execute(String sql,Object[] in) {
        boolean b=false;
        try {
            open();//保证连接是成功的
            PreparedStatement pst = conn.prepareStatement(sql);
            for(int i=0;i<in.length;i++)
                pst.setObject(i+1, in[i]);
            b = pst.execute();
            //true,执行的是一个查询语句，我们可以得到一个数据集
            //false,执行的是一个修改语句，我们可以得到一个执行成功的记录数
            if(b){
                System.out.println("----");
                /*List<ResultSet> list = new ArrayList<ResultSet>();
                list.add(pst.getResultSet());
                while(pst.getMoreResults()) {
                    list.add(pst.getResultSet());
                }*/
                return pst.getResultSet();
            }
            else {
                System.out.println("****");
                List<Integer> list = new ArrayList<Integer>();
                list.add(pst.getUpdateCount());
                while(pst.getMoreResults()) {
                    list.add(pst.getUpdateCount());
                }
                return list;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if(!b) {
                System.out.println("====");
                close();
            }
        }
        return null;
    }
    //调用存储过程  proc_Insert(?,?,?)
    public static Object executeProcedure(String procName,Object[] in) {
        open();
        try {
            procName = "{call "+procName+"(";
            String link="";
            for(int i=0;i<in.length;i++) {
                procName+=link+"?";
                link=",";
            }
            procName+=")}";
            CallableStatement cstmt = conn.prepareCall(procName);
            for(int i=0;i<in.length;i++) {
                cstmt.setObject(i+1, in[i]);
            }
            if(cstmt.execute())
            {
                return cstmt.getResultSet();
            }
            else {
                return cstmt.getUpdateCount();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        return null;
    }
    

    /*
     * 调用存储过程，并有输出参数
     * @procName ，存储过程名称：proc_Insert(?,?)
     * @in ,输入参数集合
     * @output,输出参数集合
     * @type,输出参数类型集合
     * */
    public static Object executeOutputProcedure(String procName,
            Object[] in,Object[] output,int[] type){
        Object result = null;
        try {
            CallableStatement cstmt = conn.prepareCall("{call "+procName+"}");
            //设置存储过程的参数值
            int i=0;
            for(;i<in.length;i++){//设置输入参数
                cstmt.setObject(i+1, in[i]);
                //print(i+1);
            }
            int len = output.length+i;
            for(;i<len;i++){//设置输出参数
                cstmt.registerOutParameter(i+1,type[i-in.length]);
                //print(i+1);
            }
            boolean b = cstmt.execute();
            //获取输出参数的值
            for(i=in.length;i<output.length+in.length;i++)
                output[i-in.length] = cstmt.getObject(i+1);
            if(b) {
                result = cstmt.getResultSet();
            }
            else {
                result = cstmt.getUpdateCount();
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return result;
    }
    //调用存储过程查询出所有的值
        public static Object executeProcedures(String procName) {
            open();
            try {
                procName = "{call "+procName+"}";
                CallableStatement cstmt = conn.prepareCall(procName);
                if(cstmt.execute())
                {
                    return cstmt.getResultSet();
                }
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }
}

Q4:mysql配置文件

DBDRIVER=com.mysql.jdbc.Driver
DBURL=jdbc:mysql://localhost:3306/schooldb?serverTimezone=GMT%2B8
DBUSER=root
DBPWD=123456

Q5:sqlserver配置文件

DBDRIVER=com.microsoft.sqlserver.jdbc.SQLServerDriver
DBURL=jdbc:sqlserver://localhost:1433;DatabaseName=u7528u6237u7BA1u7406s
DBUSER=sa
DBPWD=123456

注意:DBUTIL与DBUtil连着用

//以下为图片提示