大家好，我在arduino上建立一个web服务器，当发送get请求时，返回json数据，但现在是用浏览器可以读取到该json数据，但用jquery在网页里面却读取不到，是怎么回事呢？ 我将服务器的代码和客户端的代码贴下来，大家看看。
服务器代码：
#include <SPI.h>
#include <Ethernet.h>
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,1, 177);
char cmd[15];
char param1[15];
boolean systemArmed = true;
#define STRING_BUFFER_SIZE 512
char buffer[STRING_BUFFER_SIZE];
EthernetServer server(80);
void setup() {
Serial.begin(9600);
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip);
server.begin();
Serial.print("server is at ");
Serial.println(Ethernet.localIP());
}
void send404(EthernetClient client) {
client.println("HTTP/1.1 404 OK");
client.println("Content-Type: text/html");
client.println("Connnection: close");
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html><body>404</body></html>");
}
void sendStatus(EthernetClient client) {
// Send a standard http response header
Serial.println("test");
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: application/json");
//client.println("Connnection: close");
client.println();
client.println("{");
// Output the value of each analog input pin
for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
int sensorReading = analogRead(analogChannel);
client.print("\"analog_in_");
client.print(analogChannel);
client.print("\": ");
client.print(sensorReading);
// if (analogChannel != 5) {
client.println(",");
// }
}
client.print("\"system_armed\": ");
client.print( systemArmed );
client.println("\n}");
}
/**
* Parse the string and return an array which contains all path segments
*/
char** parse(char* str) {
char ** messages;
messages = (char**)malloc(sizeof(char *));
char *p;
p = strtok(str, " ");
unsigned int i = 0;
while (p != NULL) {
p = strtok(NULL, "/");
char *sp;
boolean last = false;
sp = strchr(p, ' ');
if (sp != NULL) {
*sp++ = '\0';
last = true;
}
messages[i] = p;
i++;
if (last) {
break;
}
messages = (char**)realloc(messages, sizeof(char *) * i + 1);
}
messages[i] = '\0';
return messages;
}
void armSystem() {
systemArmed = true;
}
void disarmSystem() {
systemArmed = false;
}
void handleCommand(EthernetClient client, char* cmd, char* param) {
Serial.println("jfasl;jfalskjfalsk");
if (strcmp(cmd, "status") == 0) {
Serial.println("status");
sendStatus(client);
} else if (strcmp(cmd, "arm") == 0) {
armSystem();
sendStatus(client);
Serial.println("arm");
} else if (strcmp(cmd, "disarm") == 0) {
disarmSystem();
sendStatus(client);
Serial.println("disarm");
} else {
send404(client);
}
}
int countSegments(char* str) {
int p = 0;
int count = 0;
while (str[p] != '\0') {
if (str[p] == '/') {
count++;
}
p++;
}
// We don't want to count the / in 'HTTP/1.1'
count--;
return count;
}
void loop() {
// listen for incoming clients
EthernetClient client = server.available();
if (client) {
// an http request ends with a blank line
Serial.println("in loop");
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c;
int bufindex = 0; // reset buffer
buffer[0] = client.read();
buffer[1] = client.read();
bufindex = 2;
// Read the first line to determin the request page
while (buffer[bufindex-2] != '\r' && buffer[bufindex-1] != '\n') {
//Serial.println("hahahahah");
//Serial.println(buffer[0]);
//Serial.println(buffer[1]);
// read full row and save it in buffer
c = client.read();
if (bufindex<STRING_BUFFER_SIZE) {
buffer[bufindex] = c;
Serial.println(buffer[bufindex]);
}
bufindex++;
}
// Clean buffer for next row
bufindex = 0;
// Parse the query string
int nSegments = countSegments(buffer);
char **pathsegments = parse(buffer);
int i = 0;
for(i=0; i<nSegments; i++) {
Serial.println(pathsegments[i]);
}
if (c == '\n' && currentLineIsBlank) {
handleCommand(client, pathsegments[0], pathsegments[1]);
break;
}
if (c == '\n') {
currentLineIsBlank = true;
} else if (c != '\r') {
currentLineIsBlank = false;
}
}
}
// Give the web browser time to receive the data
delay(20);
// Close the connection:
client.stop();
Serial.println("Client disonnected");
}
}
客户端代码：
<html>
<head>
<script type="text/javascript" src="jquery-2.0.2.js"></script>
<script type="text/javascript">
//window.setInterval(getData, 3000);
//var oJSON;
var xmlHttp;
function createXMLHttpRequest()
{
if(window.ActiveXObject)
{
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest)
{
xmlHttp = new XMLHttpRequest();
}
}
function startRequest()
{
createXMLHttpRequest();
try
{
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.open("GET", "http://192.168.1.177/status", true);
xmlHttp.send(null);
}
catch(exception)
{
alert("xmlHttp Fail");
}
}
function handleStateChange()
{
if(xmlHttp.readyState == 4)
{
if (xmlHttp.status == 200 || xmlHttp.status == 0)
{
var result = xmlHttp.responseText;
//var json = eval('(' + result + ')');
alert("result:="+result);
}
}
}
}
</script>
</head>
<body>
<input type="text" name="input" size=100 />
<input type="button" name="clicked" onclick="startRequest()">
</body>
</html> |
发表于 2013-6-13 21:20:19
