项目背景:
矿山的定位系统
矿工下井时,经过基站,程序要及时、准确的采集位置信息,不遗漏任何信息。
第一个实验:一个基站、15个手卡,在2分钟以内接受15个手卡的全部信息,录入数据库中,耗时越短越好;因为矿工不可能在井口停留的。
涉及知识;多线程、socket、sql批处理
缺陷:耗时长,需要改进;
误区:虽然一个基站,但是手卡多个,不是一对多就是多线程,一对单就是单线程;
多线程的概念:
可以有多个任务同时进行。
单线程的概念:
单线程在程序执行时,所走的程序路径按照连续顺序排下来,前面的必须处理好,后面的才会执行。因此,针对前面举的例子,必须等待程序完成了当前任务以后才能开始相应;
一直以来有一个很大的误解,多线程就是一个服务器对应多个客户端;
其实如果一个客户端发送的不同的数据也可以用多线程,同时接受数据;
下一篇博客用的是单线程实现和这个博客一样的功能
java代码
package cn.com.project;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Crc{
public static StringBuilder stringBuilder=null;
public static int i=0;
public static int h=0;
public static String sz[]=null;
//1,循环的基站
public static void main(String[] args) {
Port();
}
public static void Port(){
try {
ServerSocket server0= new ServerSocket(6080);
Send(server0);
} catch (IOException e1) {
}
}
public static void Send(ServerSocket server) throws IOException{
//新建一个连接客户端的线程
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
new Thread(new ThreadReader(server)).start();
}
}
jsp代码:
package cn.com.project;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.Date;
import cn.com.day01.JdbcUtils;
public class ThreadReader implements Runnable {
//初始化赋值
public static StringBuilder stringBuilder=null;
public static int i=0;
public static int h=0;
public static String sz[]=null;
private ServerSocket serverSocket;
public ThreadReader(ServerSocket serverSocket) {
this.serverSocket = serverSocket;
}
@Override
public void run() {
try {
Socket socket = this.serverSocket .accept();
read(socket.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
public static void read(InputStream is){
//我想开启多线程接受数据
stringBuilder=null;
stringBuilder=new StringBuilder();
try {
byte[] buf = new byte[1024];
int len = -1;
len = is.read(buf);
for (int i = 0; i < len; i++) {
int v = buf[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
String str=stringBuilder.toString();
if(str.length()>16){
str=str.substring(0, 16);
}
try {
othernum(str);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//只要数据不为才会进行存储
//存储到数据库中
} catch (IOException e) {
e.printStackTrace();
}
}
public static void othernum(String a) throws SQLException {
int len = a.length();
StringBuilder sb = null;
StringBuilder sb1 = null;
sb = new StringBuilder("");
sb1 = new StringBuilder("");
//
int sz[] = new int[8];
String szs[] = new String[9];
for (int n = 0; n < len / 2; n++) {// n<8
// n=0 0,2 n=1 2,2
String str = null;
str = a.substring(2 * n, 2 * n + 2);
sz[n] = Integer.parseInt(str, 16);
}
for (int i = 0; i < 9; i++) {
if (i == 0) {
sb.append(sz[0]);
}
if (i == 1) {
sb.append(sz[1]);
szs[0] = sb.toString();
}
if (i == 6) {
sb1.append(sz[i]);
}
if (i == 7) {
sb1.append(sz[i]);
szs[1] = sb1.toString();
}
if (i == 3 || i == 4 || i == 5 || i == 2) {
szs[i] = String.valueOf(sz[i]);
}
}
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
szs[6] = a;
szs[7] = df.format(new Date());
szs[8] = "1";
SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd");
Date d = new Date();
String dd = sim.format(d);
int j=0;
for (int i = 0; i < szs.length; i++) {
if(szs[i]==null||"".equals(szs[i])){
j++;
System.out.println("''''");
}
}
if(j==0){
insert_num(a, szs);
}
}
public static void insert_num(String a, String szs[]) {
int j=0;
for (int i = 0; i < szs.length; i++) {
if(szs[i]==null||"".equals(szs[i])){
j++;
System.out.println("''''");
}
}
if(j==0){
System.out.println("要插入数据库的数据串"+a);
String sql = "insert into yh(number,bs,xl,lpower,upower,alarm,data,time,state) values(?,?,?,?,?,?,?,?,?)";
JdbcUtils.update(sql, szs);
}
}
}
sql代码
package cn.com.day01;
import java.sql.*;
public class JdbcUtils {
private static final String DRIVER="com.mysql.jdbc.Driver";
private static final String URL="jdbc:mysql://localhost:3306/lf?rewriteBatchedStatements=true&useUnicode=true&characterEncoding=utf8";
private static final String root="root";
private static final String pass="root";
private static Connection conn=null;
private static PreparedStatement ps=null;
private static ResultSet rs=null;
public static Connection link(){
try {
Class.forName(DRIVER);
conn=DriverManager.getConnection(URL,root,pass);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}
//�ر�
public static void closeAll(){
if(rs!=null){
try{
rs.close();
}catch(SQLException e){
e.printStackTrace();
}
}
if(ps!=null){
try{
ps.close();
}catch(SQLException e){
e.printStackTrace();
}
}
if(conn!=null){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
}
}
}
//1.��
public static ResultSet select(String sql,String [] sz){
try{
conn=link();
ps=conn.prepareStatement(sql);
if(sz!=null){
for(int i=0;i<sz.length;i++){
ps.setString(i+1,sz[i]);
}
}
rs=ps.executeQuery();
}catch(SQLException e){
e.getStackTrace();
}
return rs;
}
//2.��ɾ��
public static void update(String sql,String [] sz) {
try{
conn=link();
ps=conn.prepareStatement(sql);
for(int i=0;i<sz.length;i++){
ps.setString(i+1,sz[i]);
}
ps.addBatch();
ps.executeBatch();
}catch(SQLException e1){
e1.printStackTrace();
}
}
}