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JAVA JDBC工具类

JAVA JDBC工具类

作者: 额嗬 | 来源:发表于2017-06-28 10:26 被阅读0次
欅坂46

前言

有时候要需要写个小程序之类的,懒得去搭什么框架。直接用jdbc多好。
更具不同的业务需求,具体操作不同。

方案一、jdbc基本连接与数据请求

一般不涉及多线程,高并发时,次工具类基本够用了

package com.security.common.util;

import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * JDBC工具类
 * Created by Administrator on 2017/1/10.
 */
public class JdbcUtil {

    // 定义数据库的链接
    private Connection conn;
    // 定义sql语句的执行对象
    private PreparedStatement pstmt;
    // 定义查询返回的结果集合
    private ResultSet rs;

    // 初始化
    public JdbcUtil(String driver, String url, String username, String password) {
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, username, password);
            System.out.println("数据库连接成功");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 更新/删除数据
        /**
        * @parm params List<String> 类型 
        **/
    public boolean updateByParams(String sql, List params) throws SQLException {
        // 影响行数
        int result = -1;
        pstmt = conn.prepareStatement(sql);
        int index = 1;
        // 填充sql语句中的占位符
        if (null != params && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i ++) {
                pstmt.setObject(index ++, params.get(i));
            }
        }
        result = pstmt.executeUpdate();
        return result > 0 ? true : false;
    }

    // 查询多条记录
    public List<Map> selectByParams(String sql, List params) throws SQLException {
        List<Map> list = new ArrayList<> ();
        int index = 1;
        pstmt = conn.prepareStatement(sql);
        if (null != params && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i ++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        rs = pstmt.executeQuery();
        ResultSetMetaData metaData = rs.getMetaData();
        int cols_len = metaData.getColumnCount();
        while (rs.next()) {
            Map map = new HashMap();
            for (int i = 0; i < cols_len; i ++) {
                String cols_name = metaData.getColumnName(i + 1);
                Object cols_value = rs.getObject(cols_name);
                if (null == cols_value) {
                    cols_value = "";
                }
                map.put(cols_name, cols_value);
            }
            list.add(map);
        }
        return list;
    }

    // 释放连接
    public void release() {
        try {
            if (null != rs) rs.close();
            if (null != pstmt) pstmt.close();
            if (null != conn) conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println("释放数据库连接");
    }

}


方案二、将工具类封装处理

稍微多了点内容,但是也没有复杂的数据处理

数据库配置文件读取方法

package com.iflytek.jdbcdemo;
 
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
 
/**
 * 数据库配置文件读取方法
 * @author administrator
 *
 */
public class DbConfig {
     
    private String driver;
    private String url;
    private String userName;
    private String password;
     
    public DbConfig() {
        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("com/iflytek/jdbcdemo/dbConfig.properties");
        Properties p=new Properties();
        try {
            p.load(inputStream);
            this.driver=p.getProperty("driver");
            this.url=p.getProperty("url");
            this.userName=p.getProperty("username");
            this.password=p.getProperty("passwrod");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
         
    }
     
    public String getDriver() {
        return driver;
    }
    public String getUrl() {
        return url;
    }
    public String getUserName() {
        return userName;
    }
    public String getPassword() {
        return password;
    }
     
}

**jdbc工具类 **

package com.iflytek.jdbcdemo;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
/**
 * jdbc工具类
 * 
 * @author administrator
 * 
 */
public final class JdbcUnits {
 
    /**
     * 数据库连接地址
     */
    private static String url ;
    /**
     * 用户名
     */
    private static String userName ;
    /**
     * 密码
     */
    private static String password;
     
    private static String driver;
 
    /**
     * 装载驱动
     */
    static {
         
        DbConfig config=new DbConfig();
        url=config.getUrl();
        userName=config.getUserName();
        password=config.getPassword();
        driver=config.getDriver();
         
        try {
            Class.forName(driver);
        } catch (ClassNotFoundException e) {
            throw new ExceptionInInitializerError(e);
        }
    }
 
    /**
     * 建立数据库连接
     * 
     * @return
     * @throws SQLException
     */
    public static Connection getConnection() throws SQLException {
        Connection conn = null;
        conn = DriverManager.getConnection(url, userName, password);
        return conn;
    }
 
    /**
     * 释放连接
     * @param conn
     */
    private static void freeConnection(Connection conn) {
        try {
            conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
 
    /**
     * 释放statement
     * @param statement
     */
    private static void freeStatement(Statement statement) {
        try {
            statement.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
 
    /**
     * 释放resultset
     * @param rs
     */
    private static void freeResultSet(ResultSet rs) {
        try {
            rs.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
 
    /**
     * 释放资源
     * 
     * @param conn
     * @param statement
     * @param rs
     */
    public static void free(Connection conn, Statement statement, ResultSet rs) {
        if (rs != null) {
            freeResultSet(rs);
        }
        if (statement != null) {
            freeStatement(statement);
        }
        if (conn != null) {
            freeConnection(conn);
        }
    }
 
}

**数据库访问帮助类 **

package com.iflytek.jdbcdemo;
 
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
/**
 * 数据库访问帮助类
 * 
 * @author administrator
 * 
 */
public class JdbcHelper {
 
    private static Connection conn = null;
    private static PreparedStatement preparedStatement = null;
    private static CallableStatement callableStatement = null;
 
    /**
     * 用于查询,返回结果集
     * 
     * @param sql
     *            sql语句
     * @return 结果集
     * @throws SQLException
     */
    @SuppressWarnings("rawtypes")
    public static List query(String sql) throws SQLException {
 
        ResultSet rs = null;
        try {
            getPreparedStatement(sql);
            rs = preparedStatement.executeQuery();
 
            return ResultToListMap(rs);
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
 
    }
 
    /**
     * 用于带参数的查询,返回结果集
     * 
     * @param sql
     *            sql语句
     * @param paramters
     *            参数集合
     * @return 结果集
     * @throws SQLException
     */
    @SuppressWarnings("rawtypes")
    public static List query(String sql, Object... paramters)
            throws SQLException {
 
        ResultSet rs = null;
        try {
            getPreparedStatement(sql);
 
            for (int i = 0; i < paramters.length; i++) {
                preparedStatement.setObject(i + 1, paramters[i]);
            }
            rs = preparedStatement.executeQuery();
            return ResultToListMap(rs);
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    /**
     * 返回单个结果的值,如count\min\max等等
     * 
     * @param sql
     *            sql语句
     * @return 结果集
     * @throws SQLException
     */
    public static Object getSingle(String sql) throws SQLException {
        Object result = null;
        ResultSet rs = null;
        try {
            getPreparedStatement(sql);
            rs = preparedStatement.executeQuery();
            if (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
 
    }
 
    /**
     * 返回单个结果值,如count\min\max等
     * 
     * @param sql
     *            sql语句
     * @param paramters
     *            参数列表
     * @return 结果
     * @throws SQLException
     */
    public static Object getSingle(String sql, Object... paramters)
            throws SQLException {
        Object result = null;
        ResultSet rs = null;
        try {
            getPreparedStatement(sql);
 
            for (int i = 0; i < paramters.length; i++) {
                preparedStatement.setObject(i + 1, paramters[i]);
            }
            rs = preparedStatement.executeQuery();
            if (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    /**
     * 用于增删改
     * 
     * @param sql
     *            sql语句
     * @return 影响行数
     * @throws SQLException
     */
    public static int update(String sql) throws SQLException {
 
        try {
            getPreparedStatement(sql);
 
            return preparedStatement.executeUpdate();
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free();
        }
    }
 
    /**
     * 用于增删改(带参数)
     * 
     * @param sql
     *            sql语句
     * @param paramters
     *            sql语句
     * @return 影响行数
     * @throws SQLException
     */
    public static int update(String sql, Object... paramters)
            throws SQLException {
        try {
            getPreparedStatement(sql);
 
            for (int i = 0; i < paramters.length; i++) {
                preparedStatement.setObject(i + 1, paramters[i]);
            }
            return preparedStatement.executeUpdate();
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free();
        }
    }
 
    /**
     * 插入值后返回主键值
     * 
     * @param sql
     *            插入sql语句
     * @return 返回结果
     * @throws Exception
     */
    public static Object insertWithReturnPrimeKey(String sql)
            throws SQLException {
        ResultSet rs = null;
        Object result = null;
        try {
            conn = JdbcUnits.getConnection();
            preparedStatement = conn.prepareStatement(sql,
                    PreparedStatement.RETURN_GENERATED_KEYS);
            preparedStatement.execute();
            rs = preparedStatement.getGeneratedKeys();
            if (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        }
    }
 
    /**
     * 插入值后返回主键值
     * 
     * @param sql
     *            插入sql语句
     * @param paramters
     *            参数列表
     * @return 返回结果
     * @throws SQLException
     */
    public static Object insertWithReturnPrimeKey(String sql,
            Object... paramters) throws SQLException {
        ResultSet rs = null;
        Object result = null;
        try {
            conn = JdbcUnits.getConnection();
            preparedStatement = conn.prepareStatement(sql,
                    PreparedStatement.RETURN_GENERATED_KEYS);
            for (int i = 0; i < paramters.length; i++) {
                preparedStatement.setObject(i + 1, paramters[i]);
            }
            preparedStatement.execute();
            rs = preparedStatement.getGeneratedKeys();
            if (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        }
 
    }
 
    /**
     * 调用存储过程执行查询
     * 
     * @param procedureSql
     *            存储过程
     * @return
     * @throws SQLException
     */
    @SuppressWarnings("rawtypes")
    public static List callableQuery(String procedureSql) throws SQLException {
        ResultSet rs = null;
        try {
            getCallableStatement(procedureSql);
            rs = callableStatement.executeQuery();
            return ResultToListMap(rs);
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    /**
     * 调用存储过程(带参数),执行查询
     * 
     * @param procedureSql
     *            存储过程
     * @param paramters
     *            参数表
     * @return
     * @throws SQLException
     */
    @SuppressWarnings("rawtypes")
    public static List callableQuery(String procedureSql, Object... paramters)
            throws SQLException {
        ResultSet rs = null;
        try {
            getCallableStatement(procedureSql);
 
            for (int i = 0; i < paramters.length; i++) {
                callableStatement.setObject(i + 1, paramters[i]);
            }
            rs = callableStatement.executeQuery();
            return ResultToListMap(rs);
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    /**
     * 调用存储过程,查询单个值
     * 
     * @param procedureSql
     * @return
     * @throws SQLException
     */
    public static Object callableGetSingle(String procedureSql)
            throws SQLException {
        Object result = null;
        ResultSet rs = null;
        try {
            getCallableStatement(procedureSql);
            rs = callableStatement.executeQuery();
            while (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    /**
     * 调用存储过程(带参数),查询单个值
     * 
     * @param procedureSql
     * @param parameters
     * @return
     * @throws SQLException
     */
    public static Object callableGetSingle(String procedureSql,
            Object... paramters) throws SQLException {
        Object result = null;
        ResultSet rs = null;
        try {
            getCallableStatement(procedureSql);
 
            for (int i = 0; i < paramters.length; i++) {
                callableStatement.setObject(i + 1, paramters[i]);
            }
            rs = callableStatement.executeQuery();
            while (rs.next()) {
                result = rs.getObject(1);
            }
            return result;
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free(rs);
        }
    }
 
    public static Object callableWithParamters(String procedureSql)
            throws SQLException {
        try {
            getCallableStatement(procedureSql);
            callableStatement.registerOutParameter(0, Types.OTHER);
            callableStatement.execute();
            return callableStatement.getObject(0);
 
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free();
        }
 
    }
 
    /**
     * 调用存储过程,执行增删改
     * 
     * @param procedureSql
     *            存储过程
     * @return 影响行数
     * @throws SQLException
     */
    public static int callableUpdate(String procedureSql) throws SQLException {
        try {
            getCallableStatement(procedureSql);
            return callableStatement.executeUpdate();
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free();
        }
    }
 
    /**
     * 调用存储过程(带参数),执行增删改
     * 
     * @param procedureSql
     *            存储过程
     * @param parameters
     * @return 影响行数
     * @throws SQLException
     */
    public static int callableUpdate(String procedureSql, Object... parameters)
            throws SQLException {
        try {
            getCallableStatement(procedureSql);
            for (int i = 0; i < parameters.length; i++) {
                callableStatement.setObject(i + 1, parameters[i]);
            }
            return callableStatement.executeUpdate();
        } catch (SQLException e) {
            throw new SQLException(e);
        } finally {
            free();
        }
    }
 
    /**
     * 批量更新数据
     * 
     * @param sqlList
     *            一组sql
     * @return
     */
    public static int[] batchUpdate(List<String> sqlList) {
 
        int[] result = new int[] {};
        Statement statenent = null;
        try {
            conn = JdbcUnits.getConnection();
            conn.setAutoCommit(false);
            statenent = conn.createStatement();
            for (String sql : sqlList) {
                statenent.addBatch(sql);
            }
            result = statenent.executeBatch();
            conn.commit();
        } catch (SQLException e) {
            try {
                conn.rollback();
            } catch (SQLException e1) {
                // TODO Auto-generated catch block
                throw new ExceptionInInitializerError(e1);
            }
            throw new ExceptionInInitializerError(e);
        } finally {
            free(statenent, null);
        }
        return result;
    }
 
    @SuppressWarnings({ "unchecked", "rawtypes" })
    private static List ResultToListMap(ResultSet rs) throws SQLException {
        List list = new ArrayList();
        while (rs.next()) {
            ResultSetMetaData md = rs.getMetaData();
            Map map = new HashMap();
            for (int i = 1; i < md.getColumnCount(); i++) {
                map.put(md.getColumnLabel(i), rs.getObject(i));
            }
            list.add(map);
        }
        return list;
    }
 
    /**
     * 获取PreparedStatement
     * 
     * @param sql
     * @throws SQLException
     */
    private static void getPreparedStatement(String sql) throws SQLException {
        conn = JdbcUnits.getConnection();
        preparedStatement = conn.prepareStatement(sql);
    }
 
    /**
     * 获取CallableStatement
     * 
     * @param procedureSql
     * @throws SQLException
     */
    private static void getCallableStatement(String procedureSql)
            throws SQLException {
        conn = JdbcUnits.getConnection();
        callableStatement = conn.prepareCall(procedureSql);
    }
 
    /**
     * 释放资源
     * 
     * @param rs
     *            结果集
     */
    public static void free(ResultSet rs) {
 
        JdbcUnits.free(conn, preparedStatement, rs);
    }
 
    /**
     * 释放资源
     * 
     * @param statement
     * @param rs
     */
    public static void free(Statement statement, ResultSet rs) {
        JdbcUnits.free(conn, statement, rs);
    }
 
    /**
     * 释放资源
     */
    public static void free() {
 
        free(null);
    }
 
}

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