javaudp代码 java udp编程

java怎么实现JSON打包UDPjava实现JSON打包UDP cJSON支持在C程序中创建和解析JSON数据 , 其提供多种方法供C程序使用 , 最直接的是将cJSON.c和cJSON.h加入到C工程中
(1) QJsonObject用于在Qt中创建JSON对象
(2)数据传输通过UDP运行
代码如下
首先在pro文件中加入
QT += network
h文件内容:
首先在pro文件中加入
QT += network
h文件内容:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include QMainWindow
#includeQtNetwork
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
【javaudp代码 java udp编程】Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
QUdpSocket *sender;
QByteArray byteArray;
private slots:
void on_pushButton_clicked();
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
cpp文件内容:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#includeQJsonObject
#includeQJsonDocument
#includeQDebug
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui-setupUi(this);
sender = new QUdpSocket(this);
QJsonObject rectJson;
rectJson.insert("Type","Rectangle");
rectJson.insert("height",42);
rectJson.insert("widght",23);
QJsonDocument rectJsonDoc;
rectJsonDoc.setObject(rectJson);
byteArray = rectJsonDoc.toJson(QJsonDocument::Compact);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButton_clicked()
{
QHostAddress address;
address.setAddress(QString("192.168.230.140"));
sender-writeDatagram(byteArray.data(),byteArray.size(),
address,4444);
}
程序通过端口4444,向IP为192.168.230.140的主机发送JSON数据
C程序如下:
{
int sock_fd;
char rcv_buff[512];
struct sockaddr_in client_addr;
struct sockaddr_in server_addr;
int client_len;
int rcv_num = -1;
if ((sock_fd = socket(AF_INET, SOCK_DGRAM,0))0)
{
perror("socket create error\n");
exit(1);
}
memset(server_addr,0,sizeof(struct sockaddr_in));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(4444);
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
client_len = sizeof(struct sockaddr_in);
if (bind(sock_fd, (struct sockaddr *)server_addr, sizeof(struct sockaddr_in))0)
{
perror("bind socket error.\n");
exit(1);
}
while (1)
{
/*zero the buff of rvbsm and hvbsm? zhp*/
rcv_num= recvfrom(sock_fd, rcv_buff, sizeof(rcv_buff), 0, (struct sockaddr*)client_addr, client_len);
if (rcv_num0)
{
rcv_buff[rcv_num] = '\0';
printf("rx bsm num = %d\n",rcv_num);
//printf();
printf("%s %u says: %s\n",inet_ntoa(client_addr.sin_addr),ntohs(client_addr.sin_port),rcv_buff);
//parse_UDP_data(rcv_num,rcv_buff);
if(rcv_buff != NULL)
{
cJSON* pJson = cJSON_Parse(rcv_buff);
if(pJson == NULL)
{
printf("Json Parse failed.\n");
return 0;
}
cJSON* pSub1 = cJSON_GetObjectItem(pJson,"Type");
cJSON* pSub2 = cJSON_GetObjectItem(pJson,"height");
cJSON* pSub3 = cJSON_GetObjectItem(pJson,"widght");
if(pSub1!=NULL)
{
printf("Type : %s\n", pSub1-valuestring);
}
if(pSub2!=NULL)
{
printf("height : %d\n", pSub2-valueint);
}
if(pSub3!=NULL)
{
printf("widght : %d\n", pSub3-valueint);
}
}
}
else
{
perror("recv BSM error\n");
break;
}
}
close(sock_fd);
}
编译C程序:gcc -I. -lm -o rencode *.c

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