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gistfile1.txt
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package lanqiao.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import com.mysql.jdbc.ResultSetMetaData;
/**
* JDBC链接mysql数据库查询
* @author xyb
*
*/
public class SqlHelper {
private static final String url="jdbc:mysql://10.8.0.163:3306/test?Unicode=true&characterEncoding=utf-8&useSSL=false";
private static final String user="root";
private static final String password="admin";
//static Connection conn=null;全局唯一,线程不安全
static ThreadLocal<Connection> local=new ThreadLocal<Connection>();
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static Connection openConnection(){
Connection conn=local.get();
try {
if(conn==null||conn.isClosed()){
conn=DriverManager.getConnection(url,user,password);
local.set(conn);
}
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
*
* @param sql
* @param objects
* @return
*/
public static List<HashMap<String,Object>> select1(String sql,Object ... objects){
Connection conn=SqlHelper.openConnection();
PreparedStatement pre=null;
ResultSet re=null;
List<HashMap<String,Object>>rows=new ArrayList<HashMap<String,Object>>();
try {
pre=conn.prepareStatement(sql);
if(pre!=null){
for(int i=0;i<objects.length;i++){
pre.setObject(i+1, objects[i]);
}
}
re= pre.executeQuery();
java.sql.ResultSetMetaData remeta=re.getMetaData();
//获取列头元素
int length =remeta.getColumnCount();
//获取列的数量
while(re.next()){
HashMap<String,Object> map=new HashMap<String,Object>();
for(int i=0;i<length;i++){
String columnlable=remeta.getColumnLabel(i+1);
map.put(columnlable, re.getObject(columnlable));
//根据列的标签名获取数据
}
rows.add(map);
}
//数据解析完毕,调用了实现子类Mapping的方法
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw new RuntimeException("执行出错",e);
}finally{
if(re!=null){
try {
re.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return rows;
}
/**
* 查询
* @param sql
* @param handerMapper
* @param objects
* @return
*/
public static <T>List<T> select(String sql,RowHandlerMapper<T>handerMapper,Object...objects){
Connection conn=SqlHelper.openConnection();
PreparedStatement pre=null;
ResultSet re=null;
List<T>rows=null;
try {
pre=conn.prepareStatement(sql);
if(pre!=null){
for(int i=0;i<objects.length;i++){
pre.setObject(i+1, objects[i]);
}
}
re= pre.executeQuery();
rows=handerMapper.mapping(re);
//数据解析完毕,调用了实现子类Mapping的方法
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw new RuntimeException("执行出错",e);
}finally{
if(re!=null){
try {
re.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return rows;
}
public void close(){
Connection conn=local.get();
if(conn!=null){
try {
conn.close();
local.remove();
conn=null;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
interface RowHandlerMapper<T>{
public List<T> mapping(ResultSet re);
}
package lanqiao.test;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class Test {
public static void main(String[] args) {
String sql="select * from user";
List<HashMap<String,Object>> li=SqlHelper.select1(sql);
for(HashMap<String,Object> h:li){
System.out.println(h.get("id"));
}
List<User>list=SqlHelper.select(sql,new RowHandlerMapper<User>() {
@Override
public List<User> mapping(ResultSet re) {
List<User>list=new ArrayList<User>();
try {
while(re.next()){
User user=new User();
user.setEmail(re.getString(3));
user.setName(re.getString(2));
user.setId(re.getString(1));
list.add(user);
}
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException("执行出错",e);
}
return list;
}
});
for(User u:list){
System.out.println(u.getId());
System.out.println(u.getName());
}
}
}
class User{
String id;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
String name;
String email;
}
package edutaru.test;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class Testsql {
public static void main(String[] args) {
String sql="select * from employee where id=? and name=?";
List<HashMap<String,Object>> li=SqlHelper.select1(sql,21,"lucy");
for(HashMap<String,Object> h:li){
System.out.println(h.get("id"));
System.out.println(h.get("name"));
System.out.println(h.get("sex"));
}
String sql1="select * from employee";
List<HashMap<String,Object>> lis=SqlHelper.select1(sql1);
for(HashMap<String,Object> h:lis){
System.out.println(h.get("id"));
}
List<User>list =SqlHelper.select(sql, new RowHandlerMapper<User>() {
List<User> l=new ArrayList<User>();
@Override
public List mapping(ResultSet re) {
try {
while(re.next()){
User user=new User();
user.setId(re.getString(1));
user.setName(re.getString(2));
user.setEmail(re.getString(4));
l.add(user);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return l;
}
},21,"lucy");
for(User user:list){
System.out.println(user.getId());
System.out.println(user.getName());
System.out.println(user.getEmail());
}
}
}
class User{
String id;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getTelephone() {
return telephone;
}
public void setTelephone(String telephone) {
this.telephone = telephone;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getPresent() {
return present;
}
public void setPresent(String present) {
this.present = present;
}
String name;
String sex;
String telephone;
String email;
String city;
String present;
String passsword;
public String getPasssword() {
return passsword;
}
public void setPasssword(String passsword) {
this.passsword = passsword;
}
}
package edu.taru.test;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Properties;
import com.mysql.jdbc.ResultSetMetaData;
/**
* JDBC链接mysql数据库查询
* @author xyb
*
*/
public class SqlHelper {
private static Properties properties=new Properties();
private static final String url="";
private static final String user="";
private static final String password="";
//static Connection conn=null;全局唯一,线程不安全
static ThreadLocal<Connection> local=new ThreadLocal<Connection>();
//读
static{
try {
properties.load(SqlHelper.class.getClassLoader().getResourceAsStream("jdbc.properties"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
static{
try {
Class.forName(properties.getProperty("driver"));
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static Connection openConnection(){
Connection conn=local.get();
try {
if(conn==null||conn.isClosed()){
conn=DriverManager.getConnection(properties.getProperty("url"),properties.getProperty("user"),properties.getProperty("password"));
local.set(conn);
}
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
*
* @param sql
* @param objects
* @return
*/
public static List<HashMap<String,Object>> select1(String sql,Object ... objects){
Connection conn=SqlHelper.openConnection();
PreparedStatement pre=null;
ResultSet re=null;
List<HashMap<String,Object>>rows=new ArrayList<HashMap<String,Object>>();
try {
pre=conn.prepareStatement(sql);
if(pre!=null){
for(int i=0;i<objects.length;i++){
pre.setObject(i+1, objects[i]);
}
}
re= pre.executeQuery();
java.sql.ResultSetMetaData remeta=re.getMetaData();
//获取列头元素
int length =remeta.getColumnCount();
//获取列的数量
while(re.next()){
HashMap<String,Object> map=new HashMap<String,Object>();
for(int i=0;i<length;i++){
String columnlable=remeta.getColumnLabel(i+1);
map.put(columnlable, re.getObject(columnlable));
//根据列的标签名获取数据
}
rows.add(map);
}
//数据解析完毕,调用了实现子类Mapping的方法
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw new RuntimeException("执行出错",e);
}finally{
if(re!=null){
try {
re.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return rows;
}
/**
* 查询
* @param sql
* @param handerMapper
* @param objects
* @return
*/
public static <T>List<T> select(String sql,RowHandlerMapper<T>handerMapper,Object...objects){
Connection conn=SqlHelper.openConnection();
PreparedStatement pre=null;
ResultSet re=null;
List<T>rows=null;
try {
pre=conn.prepareStatement(sql);
if(pre!=null){
for(int i=0;i<objects.length;i++){
pre.setObject(i+1, objects[i]);
}
}
re= pre.executeQuery();
rows=handerMapper.mapping(re);
//数据解析完毕,调用了实现子类Mapping的方法
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw new RuntimeException("执行出错",e);
}finally{
if(re!=null){
try {
re.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return rows;
}
public void close(){
Connection conn=local.get();
if(conn!=null){
try {
conn.close();
local.remove();
conn=null;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
interface RowHandlerMapper<T>{
public List<T> mapping(ResultSet re);
}
jdbc.properties
原始数据 复制代码
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://10.8.0.131:3306/test?Unicode=true&characterEncoding=utf-8&useSSL=false
user=root
password=admin

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