package com.DBUtils;
import java.lang.reflect.Field;
import java.sql.Connection;
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.HashMap;
import java.util.List;
import java.util.Map;
import com.bean.UserInfo;
public class JdbcUtils {
private static final String USERNAME = "system";//数据库用户名
private static final String PASSWORD = "zZ123456";//数据库密码
private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";//驱动信息
private static final String URL = "jdbc:oracle:thin:@localhost:1521:bookstore";//数据库地址
private Connection connection = null;
private PreparedStatement statement = null;
private ResultSet resultSet = null;
public JdbcUtils() {
try {
Class.forName(DRIVER);
System.out.println("Connect database Successlly！");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/**
* 得到数据库连接
* @return connection
*/
public Connection getConnection() {
try {
connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
/**
* 更新操作（增删改）
* @param sql
* @param params
* @return boolean
* @throws SQLException
*/
public boolean updateByPreparedStatement(String sql,List<Object> params) throws SQLException {
boolean flag = false;
int result = -1;
statement = connection.prepareStatement(sql);
int index = 1;
if(params != null && !params.isEmpty()){
for(int i=0; i<params.size(); i++){
statement.setObject(index++, params.get(i));
}
}
result = statement.executeUpdate();
return flag = result > 0 ? true : false;
}
/**
* 查询单条数据
* @param sql
* @param params
* @return
* @throws SQLException
*/
public Map<String,Object> findSimpleResult(String sql,List<Object> params) throws SQLException {
Map<String,Object> map = new HashMap<String, Object>();
statement = connection.prepareStatement(sql);
int index = 1;
if(params != null && !params.isEmpty()){
for(int i=0; i<params.size(); i++){
statement.setObject(index++, params.get(i));
}
}
resultSet = statement.executeQuery();//返回查询结果
ResultSetMetaData metaData = resultSet.getMetaData();
int col_len = metaData.getColumnCount();
while (resultSet.next()) {
for(int i=0; i<col_len; i++){
String cols_name = metaData.getCatalogName(i+1).toLowerCase();
Object cols_value = resultSet.getObject(cols_name);
if(cols_value == null){
cols_value = "";
}
map.put(cols_name, cols_value);
}
}
return map;
}
/**
* 查询多条数据
* @param sql
* @param params
* @return
* @throws SQLException
*/
public List<Map<String, Object>> findModeResult(String sql, List<Object> params) throws SQLException{
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
int index = 1;
statement = connection.prepareStatement(sql);
if(params != null && !params.isEmpty()){
for(int i = 0; i<params.size(); i++){
statement.setObject(index++, params.get(i));
}
}
resultSet = statement.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while(resultSet.next()){
Map<String, Object> map = new HashMap<String, Object>();
for(int i=0; i<cols_len; i++){
String cols_name = metaData.getColumnName(i+1).toLowerCase();
Object cols_value = resultSet.getObject(cols_name);
if(cols_value == null){
cols_value = "";
}
map.put(cols_name, cols_value);
}
list.add(map);
}
return list;
}
/*
* 通过反射机制查询单条记录
* @param sql
* @param params
* @param cls
* @return
* @throws Exception
*/
public <T> T findSimpleRefResult(String sql, List<Object> params,
Class<T> cls )throws Exception{
T resultObject = null;
int index = 1;
statement = connection.prepareStatement(sql);
if(params != null && !params.isEmpty()){
for(int i = 0; i<params.size(); i++){
statement.setObject(index++, params.get(i));
}
}
resultSet = statement.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while(resultSet.next()){
//通过反射机制创建一个实例
resultObject = cls.newInstance();
for(int i = 0; i<cols_len; i++){
String cols_name = metaData.getColumnName(i+1).toLowerCase();
Object cols_value = resultSet.getObject(cols_name);
if(cols_value == null){
cols_value = "";
}
Field field = cls.getDeclaredField(cols_name);
field.setAccessible(true); //打开javabean的访问权限
field.set(resultObject, cols_value);
}
}
return resultObject;
}
/**
* 通过反射查询多条记录
* @param sql
* @param params
* @param cls
* @return
* @throws Exception
*/
public <T> List<T> findMoreRefResult(String sql, List<Object> params,
Class<T> cls )throws Exception {
List<T> list = new ArrayList<T>();
int index = 1;
statement = connection.prepareStatement(sql);
if(params != null && !params.isEmpty()){
for(int i = 0; i<params.size(); i++){
statement.setObject(index++, params.get(i));
}
}
resultSet = statement.executeQuery();
ResultSetMetaData metaData = resultSet.getMetaData();
int cols_len = metaData.getColumnCount();
while(resultSet.next()){
//通过反射机制创建一个实例
T resultObject = cls.newInstance();
for(int i = 0; i<cols_len; i++){
String cols_name = metaData.getColumnName(i+1).toLowerCase();
Object cols_value = resultSet.getObject(cols_name);
if(cols_value == null){
cols_value = "";
}
Field field = cls.getDeclaredField(cols_name);
field.setAccessible(true); //打开javabean的访问权限
field.set(resultObject, cols_value);
}
list.add(resultObject);
}
return list;
}
public void Conn(){
if(resultSet != null){
try{
resultSet.close();
}catch(SQLException e){
e.printStackTrace();
}
}
if(statement != null){
try{
statement.close();
}catch(SQLException e){
e.printStackTrace();
}
}
if(connection != null){
try{
connection.close();
}catch(SQLException e){
e.printStackTrace();
}
}
}
public static void main(String[] args) {
JdbcUtils jdbcUtils = new JdbcUtils();
jdbcUtils.getConnection();
/*******************增*********************/
/*
String sql = "insert into userinfo (username, password) values (?, ?)";
List<Object> params = new ArrayList<Object>();
params.add("02");
params.add("02");
try {
boolean flag = jdbcUtils.updateByPreparedStatement(sql, params);
System.out.println(flag);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
jdbcUtils.Conn();
}
*/
/*******************删*********************/
//删除名字为张三的记录
/*
String sql = "delete from userinfo where username = ?";
List<Object> params = new ArrayList<Object>();
params.add("7");
try {
boolean flag = jdbcUtils.updateByPreparedStatement(sql, params);
System.out.println(flag);
} catch (SQLException e) {
e.printStackTrace();
} finally{
jdbcUtils.Conn();
}
*/
/*******************改*********************/
/*
String sql = "update userinfo set password = ? where username = ? ";
List<Object> params = new ArrayList<Object>();
params.add("233333");
params.add("01");
boolean flag;
try {
flag = jdbcUtils.updateByPreparedStatement(sql, params);
System.out.println(flag);
} catch (SQLException e) {
e.printStackTrace();
} finally{
jdbcUtils.Conn();
}
*/
/*******************查*********************/
//不利用反射查询多个记录
/*
String sql2 = "select * from userinfo";
List<Map<String, Object>> list;
try {
list = jdbcUtils.findModeResult(sql2, null);
System.out.println(list); //list toSteing() 直接输出
} catch (SQLException e) {
e.printStackTrace();
}finally{
jdbcUtils.Conn();
}*/
/*
//不利用反射查询单个记录 （出不来！！！）
String sql2 = "select * from userinfo where username = ?";
Map<String,Object> map;//
List<Object> params = new ArrayList<Object>();
params.add("01");
Map<String, Object> userinfo ;
try{
userinfo = jdbcUtils.findSimpleResult(sql2, params);
System.out.println(userinfo);
}catch(Exception e){
}finally{
jdbcUtils.Conn();
}
*/
/*
//利用反射查询单条记录
String sql = "select * from userinfo where username = ? ";
List<Object> params = new ArrayList<Object>();
params.add("01");
UserInfo userInfo;
try {
userInfo = jdbcUtils.findSimpleRefResult(sql, params, UserInfo.class);
System.out.print(userInfo);
} catch (Exception e) {
e.printStackTrace();
}finally{
jdbcUtils.Conn();
}
*/
/*
//利用反射查询多条记录
String sql = "select * from userinfo where username = ?";
List<Object> params = new ArrayList<Object>();
params.add("02");
List<UserInfo> list;
try {
list = jdbcUtils.findMoreRefResult(sql, params, UserInfo.class);
System.out.print(list);
} catch (Exception e) {
e.printStackTrace();
}finally{
jdbcUtils.Conn();
}
*/
}
}
package com.bean;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Date;
public class UserInfo implements Serializable{
private static final long serialVersionUID = 1L;
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "UserInfo [username=" + username + ", password=" + password
+ ", getClass()=" + getClass() + ", hashCode()=" + hashCode()
+ ", toString()=" + super.toString() + "]";
}
}
