我有一个＆＃34; index.htm＆＃34;文件加载到以太网屏蔽的SD卡上。它用于将文本从网页发送到Arduino以便在LCD上显示。它工作正常，直到这里。当我尝试向Arduino Web服务器添加基本HTTP身份验证时出现问题。网站加载但我输入的文字没有显示在液晶显示屏上。我检查了LCD连接，没有问题。我认为我在Arduino上的代码存在问题。这是没有HTTP身份验证的Arduino代码：
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#include <LiquidCrystal.h>
// size of buffer used to capture HTTP requests
#define REQ_BUF_SZ 40
// size of buffer that stores a line of text for the LCD + null terminator
#define LCD_BUF_SZ 17
// MAC address from Ethernet shield sticker under board
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,1,6); // IP address, may need to change depending on network
EthernetServer server(80); // create a server at port 80
File webFile; // the web page file on the SD card
char HTTP_req[REQ_BUF_SZ] = {0}; // buffered HTTP request stored as null terminated string
char req_index = 0; // index into HTTP_req buffer
char lcd_buf_1[LCD_BUF_SZ] = {0};// buffer to save LCD line 1 text to
char lcd_buf_2[LCD_BUF_SZ] = {0};// buffer to save LCD line 2 text to
LiquidCrystal lcd(10,9,8,7,6,5);
void setup()
{
// disable Ethernet chip
pinMode(10, OUTPUT);
digitalWrite(10, HIGH);
Serial.begin(115200); // for debugging
lcd.begin(16, 2);
// Message on LCD
lcd.print(F("Initializing"));
// initialize SD card
Serial.println("Initializing SD card...");
if (!SD.begin(4)) {
Serial.println("ERROR - SD card initialization failed!");
lcd.print(F("SD init failed"));
return; // init failed
}
Serial.println("SUCCESS - SD card initialized.");
// check for index.htm file
if (!SD.exists("index.htm")) {
Serial.println("ERROR - Can't find index.htm file!");
return; // can't find index file
}
Serial.println("SUCCESS - Found index.htm file.");
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
// End of initialization message on LCD + print IP address
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(F("Done."));
lcd.setCursor(0, 1);
lcd.print(ip);
}
void loop()
{
EthernetClient client = server.available(); // try to get client
if (client) { // got client?
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) { // client data available to read
char c = client.read(); // read 1 byte (character) from client
// limit the size of the stored received HTTP request
// buffer first part of HTTP request in HTTP_req array (string)
// leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
if (req_index < (REQ_BUF_SZ - 1)) {
HTTP_req[req_index] = c; // save HTTP request character
req_index++;
}
// last line of client request is blank and ends with \n
// respond to client only after last line received
if (c == '\n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
// remainder of header follows below, depending on if
// web page or XML page is requested
// Ajax request - send XML file
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
// print the received text to the LCD if found
if (GetLcdText(lcd_buf_1, lcd_buf_2, LCD_BUF_SZ)) {
// lcd_buf_1 and lcd_buf_2 now contain the text from
// the web page
// write the received text to the LCD
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(lcd_buf_1);
lcd.setCursor(0, 1);
lcd.print(lcd_buf_2);
}
}
else { // web page request
// send rest of HTTP header
client.println("Content-Type: text/html");
client.println("Connection: keep-alive");
client.println();
// send web page
webFile = SD.open("index.htm"); // open web page file
if (webFile) {
Serial.println("Successfully opened webfile");
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
}
// reset buffer index and all buffer elements to 0
req_index = 0;
StrClear(HTTP_req, REQ_BUF_SZ);
break;
}
// every line of text received from the client ends with \r\n
if (c == '\n') {
// last character on line of received text
// starting new line with next character read
currentLineIsBlank = true;
}
else if (c != '\r') {
// a text character was received from client
currentLineIsBlank = false;
}
} // end if (client.available())
} // end while (client.connected())
delay(1); // give the web browser time to receive the data
client.stop(); // close the connection
} // end if (client)
}
// get the two strings for the LCD from the incoming HTTP GET request
boolean GetLcdText(char *line1, char *line2, int len)
{
boolean got_text = false; // text received flag
char *str_begin; // pointer to start of text
char *str_end; // pointer to end of text
int str_len = 0;
int txt_index = 0;
char *current_line;
current_line = line1;
// get pointer to the beginning of the text
str_begin = strstr(HTTP_req, "&L1=");
for (int j = 0; j < 2; j++) { // do for 2 lines of text
if (str_begin != NULL) {
str_begin = strstr(str_begin, "="); // skip to the =
str_begin += 1; // skip over the =
str_end = strstr(str_begin, "&");
if (str_end != NULL) {
str_end[0] = 0; // terminate the string
str_len = strlen(str_begin);
// copy the string to the buffer and replace %20 with space ' '
for (int i = 0; i < str_len; i++) {
if (str_begin[i] != '%') {
if (str_begin[i] == 0) {
// end of string
break;
}
else {
current_line[txt_index++] = str_begin[i];
if (txt_index >= (len - 1)) {
// keep the output string within bounds
break;
}
}
}
else {
// replace %20 with a space
if ((str_begin[i + 1] == '2') && (str_begin[i + 2] == '0')) {
current_line[txt_index++] = ' ';
i += 2;
if (txt_index >= (len - 1)) {
// keep the output string within bounds
break;
}
}
}
} // end for i loop
// terminate the string
current_line[txt_index] = 0;
if (j == 0) {
// got first line of text, now get second line
str_begin = strstr(&str_end[1], "L2=");
current_line = line2;
txt_index = 0;
}
got_text = true;
}
}
} // end for j loop
return got_text;
}
// sets every element of str to 0 (clears array)
void StrClear(char *str, char length)
{
for (int i = 0; i < length; i++) {
str[i] = 0;
}
}
// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
char found = 0;
char index = 0;
char len;
len = strlen(str);
if (strlen(sfind) > len) {
return 0;
}
while (index < len) {
if (str[index] == sfind[found]) {
found++;
if (strlen(sfind) == found) {
return 1;
}
}
else {
found = 0;
}
index++;
}
return 0;
}
并且，以下是带有身份验证的代码：
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#include <LiquidCrystal.h>
// size of buffer used to capture HTTP requests
#define REQ_BUF_SZ 40
// size of buffer that stores a line of text for the LCD + null terminator
#define LCD_BUF_SZ 17
// MAC address from Ethernet shield sticker under board
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,1,12); // IP address, may need to change depending on network
EthernetServer server(80); // create a server at port 80
File webFile; // the web page file on the SD card
char HTTP_req[REQ_BUF_SZ] = {0}; // buffered HTTP request stored as null terminated string
char req_index = 0; // index into HTTP_req buffer
char lcd_buf_1[LCD_BUF_SZ] = {0};// buffer to save LCD line 1 text to
char lcd_buf_2[LCD_BUF_SZ] = {0};// buffer to save LCD line 2 text to
LiquidCrystal lcd(10,9,8,7,6,5);
void setup()
{
// disable Ethernet chip
pinMode(10, OUTPUT);
digitalWrite(10, HIGH);
Serial.begin(115200); // for debugging
lcd.begin(16, 2);
// Message on LCD
lcd.print(F("Initializing"));
// initialize SD card
Serial.println(F("Initializing SD card..."));
if (!SD.begin(4)) {
Serial.println(F("ERROR - SD card initialization failed!"));
lcd.print(F("SD init failed"));
return; // init failed
}
Serial.println(F("SUCCESS - SD card initialized."));
// check for index.htm file
if (!SD.exists("index.htm")) {
Serial.println(F("ERROR - Can't find index.htm file!"));
return; // can't find index file
}
Serial.println(F("SUCCESS - Found index.htm file."));
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
// End of initialization message on LCD + print IP address
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(F("Done."));
lcd.setCursor(0, 1);
lcd.print(ip);
}
void SendAuthentificationpage(EthernetClient &client)
{
client.println("HTTP/1.1 401 Authorization Required");
client.println("WWW-Authenticate: Basic realm=\"Secure Area\"");
client.println("Content-Type: text/html");
client.println("Connnection: close");
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<HTML> <HEAD> <TITLE>Error</TITLE>");
client.println(" </HEAD> <BODY><H1>401 Unauthorized.</H1></BODY> </HTML>");
}
boolean authentificated=false;
void loop()
{
EthernetClient client = server.available(); // try to get client
if (client) { // got client?
memset(HTTP_req,0,sizeof(HTTP_req));
authentificated=false;
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) { // client data available to read
char c = client.read(); // read 1 byte (character) from client
// limit the size of the stored received HTTP request
// buffer first part of HTTP request in HTTP_req array (string)
// leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
if (req_index < (REQ_BUF_SZ - 1)) {
HTTP_req[req_index] = c; // save HTTP request character
req_index++;
}
Serial.println(HTTP_req);
// last line of client request is blank and ends with \n
// respond to client only after last line received
if (c == '\n' && currentLineIsBlank) {
if(authentificated){
// send a standard http response header
client.println("HTTP/1.1 200 OK");
// remainder of header follows below, depending on if
// web page or XML page is requested
// Ajax request - send XML file
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
Serial.println(F("Receiving text"));
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
// print the received text to the LCD if found
if (GetLcdText(lcd_buf_1, lcd_buf_2, LCD_BUF_SZ)) {
// lcd_buf_1 and lcd_buf_2 now contain the text from
// the web page
// write the received text to the LCD
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(lcd_buf_1);
//lcd.setCursor(0, 1);
//lcd.print(lcd_buf_2);
}
}
else { // web page request
// send rest of HTTP header
client.println("Content-Type: text/html");
client.println("Connection: keep-alive");
client.println();
// send web page
webFile = SD.open("index.htm"); // open web page file
if (webFile) {
Serial.println(F("Successfully opened webfile"));
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
}
// reset buffer index and all buffer elements to 0
req_index = 0;
StrClear(HTTP_req, REQ_BUF_SZ);
break;
}
else {
SendAuthentificationpage(client);
}
break;
}
// every line of text received from the client ends with \r\n
if (c == '\n') {
// last character on line of received text
// starting new line with next character read
if (strstr(HTTP_req,"Authorization: Basic")>0 && strstr(HTTP_req,"ZWNlOm5vdGljZQ==")>0)
authentificated=true;
memset(HTTP_req,0,sizeof(HTTP_req));
req_index=0;
currentLineIsBlank = true;
}
else if (c != '\r') {
// a text character was received from client
currentLineIsBlank = false;
}
} // end if (client.available())
} // end while (client.connected())
delay(1); // give the web browser time to receive the data
client.stop(); // close the connection
} // end if (client)
}
// get the two strings for the LCD from the incoming HTTP GET request
boolean GetLcdText(char *line1, char *line2, int len)
{
//Serial.println(")
boolean got_text = false; // text received flag
char *str_begin; // pointer to start of text
char *str_end; // pointer to end of text
int str_len = 0;
int txt_index = 0;
char *current_line;
current_line = line1;
// get pointer to the beginning of the text
str_begin = strstr(HTTP_req, "&L1=");
for (int j = 0; j < 2; j++) { // do for 2 lines of text
if (str_begin != NULL) {
str_begin = strstr(str_begin, "="); // skip to the =
str_begin += 1; // skip over the =
str_end = strstr(str_begin, "&");
if (str_end != NULL) {
str_end[0] = 0; // terminate the string
str_len = strlen(str_begin);
// copy the string to the buffer and replace %20 with space ' '
for (int i = 0; i < str_len; i++) {
if (str_begin[i] != '%') {
if (str_begin[i] == 0) {
// end of string
break;
}
else {
current_line[txt_index++] = str_begin[i];
if (txt_index >= (len - 1)) {
// keep the output string within bounds
break;
}
}
}
else {
// replace %20 with a space
if ((str_begin[i + 1] == '2') && (str_begin[i + 2] == '0')) {
current_line[txt_index++] = ' ';
i += 2;
if (txt_index >= (len - 1)) {
// keep the output string within bounds
break;
}
}
}
} // end for i loop
// terminate the string
current_line[txt_index] = 0;
if (j == 0) {
// got first line of text, now get second line
str_begin = strstr(&str_end[1], "L2=");
current_line = line2;
txt_index = 0;
}
got_text = true;
}
}
} // end for j loop
return got_text;
}
// sets every element of str to 0 (clears array)
void StrClear(char *str, char length)
{
for (int i = 0; i < length; i++) {
str[i] = 0;
}
}
// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
char found = 0;
char index = 0;
char len;
len = strlen(str);
if (strlen(sfind) > len) {
return 0;
}
while (index < len) {
if (str[index] == sfind[found]) {
found++;
if (strlen(sfind) == found) {
return 1;
}
}
else {
found = 0;
}
index++;
}
return 0;
}
网站正确加载。在代码中，如果GET请求包含字符串＆＃34; ajax_input＆＃34;，则必须在LCD上显示我在网站中输入的文本。但是，这种情况并没有发生。我来到这里。请帮助！
PS：这是串口显示器的屏幕截图。可以看出，＆＃34; ajax_inputs＆＃34;明确存在于GET请求中。此外，我在网页中键入的内容显示在串行监视器中（堆栈溢出）。 serial monitor 如果您需要，我会参考这些教程：https://startingelectronics.org/tutorials/arduino/ethernet-shield-web-server-tutorial/SD-card-web-server/
