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);
}
}
