我在java中编写了一个Web服务器。它非常简单，其工作是在8181端口上回答http请求。让我们来看看代码：
public void start() throws IOException {
ServerSocket listener = new ServerSocket(8181,1000);
System.out.println("Webserver starting up on port 8181");
System.out.println("Waiting for connection");
//==========================regex
String pathRegex = "(?<=GET /).+?(?= HTTP)";
Pattern pathPattern = Pattern.compile(pathRegex);
//==========================/regex
try {
while (true) {
Socket socket = listener.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
String requestHeaders = in.readLine();
Matcher pathMatcher = pathPattern.matcher(requestHeaders);
Boolean anyPath = pathMatcher.find();
System.out.println("Connection, sending data to request : " + requestHeaders);
try {
PrintWriter out =
new PrintWriter(socket.getOutputStream(), true);
if (!anyPath) {
JustHello(out);
}
else {
String directory = pathMatcher.group();
System.out.println(directory);
if (directory.toString().equals("pic")) {
JustPic(out);
}
}
} finally {
socket.close();
}
}
}
finally {
listener.close();
}
}
private void JustHello(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Just Hello</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\nHello World\n</body>\n</html>");
out.flush();
}
private void JustPic(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Just Hello</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\n<img width=\"300px\" height=\"200\" src=\"file:///C:/ccleverJavaWebServer/images/th.jpg\"/>\n</body>\n</html>");
out.flush();
}
现在的问题是，文件的路径没问题，但确实无法正常工作。使用此＆＃34; http://localhost:8181/pic＆＃34;加载页面后一切都好，但img没有加载任何图片！
问题是什么？
答案 0 :(得分：1)
由于安全问题，您无法嵌入此类本地图片。浏览器根本不允许这种行为。请参阅this question。
答案 1 :(得分：0)
解决：对自己;） 您必须设法回答文件请求并将文件移动到项目源附近。然后让你的解决相对。这是我的代码，对我来说很好：
package ir.cclever.example;
import java.awt.List;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class WellCloseWebServer {
public class clientInfo{
public String ip;
public Date visitTime;
}
static ArrayList<clientInfo> clients = new ArrayList<clientInfo>();
public void start() throws IOException {
ServerSocket listener = new ServerSocket(8181,1000);
System.out.println("Webserver starting up on port 8181");
System.out.println("Waiting for connection");
//==========================regex
String pathRegex = "(?<=GET /).+?(?= HTTP)";
Pattern pathPattern = Pattern.compile(pathRegex);
//==========================/regex
try {
while (true) {
Socket socket = listener.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String wholeRequest = "";
String line;
String requestHeaders = in.readLine();
wholeRequest = wholeRequest.concat(requestHeaders + "\n<br>");
while(!(line = in.readLine()).equals("")){
wholeRequest = wholeRequest.concat(line + "\n<br>");
}
wholeRequest = wholeRequest.concat("\n<br/>\n<br/>\nClient IP Address : " + socket.getRemoteSocketAddress().toString());
wholeRequest = wholeRequest.concat("\n<br/>\n<br/>\nClient Opened Port : " + ((Integer)socket.getPort()).toString());
clientInfo newClient = new clientInfo();
newClient.ip = socket.getRemoteSocketAddress().toString();
newClient.visitTime = new Date();
clients.add(newClient);
Matcher pathMatcher = pathPattern.matcher(requestHeaders);
Boolean anyPath = pathMatcher.find();
System.out.println("Connection, sending data to request : " + requestHeaders);
try {
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
if (!anyPath) {
JustHello(out);
}
else {
String directory = pathMatcher.group();
System.out.println(directory);
if (directory.toString().equals("pic")) {
JustPic(out);
}
else if(directory.toString().startsWith("server/")){
getFile(directory,dos,true);
}
else if(directory.toString().endsWith("jpg")){
getFile(directory,dos,false);
}
else if(directory.toString().equals("my.aspx")){
mirror(out,wholeRequest);
}
else if(directory.toString().equals("clients.html")){
WholeClients(out);
}
else{
errorPage(out);
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
socket.close();
}
}
}
finally {
listener.close();
}
}
private void InvalidRequestMethod(PrintWriter out, String string) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 404 NOT FOUND");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Just GET</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\nInvalid request mehtod! : "+ string +"\n</body>\n</html>");
out.flush();
}
private void errorPage(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 404 NOT FOUND");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Error 404 NOT FOUND!</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\nContent not found on server!\n</body>\n</html>");
out.flush();
}
private void WholeClients(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Whole Clients</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\n");
Integer i=0;
for (clientInfo item : clients) {
i++;
out.print("<br/>\n"+i.toString()+") ip : " + item.ip + " | visit time : " + item.visitTime.toString());
}
out.print("\n</body>\n</html>");
out.flush();
}
private void mirror(PrintWriter out, String requestHeaders) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>My Info</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\n" +
requestHeaders.toString() +
"\n</body>\n</html>");
out.flush();
}
private void getFile(String directory, DataOutputStream os, boolean b) {
String CRLF = "\r\n";
// Open the requested file.
String fileName = directory;
FileInputStream fis = null;
boolean fileExists = true;
try {
//(new File(fileName)).mkdirs();
fis = new FileInputStream(fileName);
} catch (FileNotFoundException e) {
fileExists = false;
}
// Construct the response message.
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists) {
statusLine = "200 OK" + CRLF;
contentTypeLine = "Content-type: " +
contentType( fileName ) + CRLF;
} else {
statusLine = "404 NOT FOUND" + CRLF;
contentTypeLine = "Content Not Found!" + CRLF;
entityBody = "<HTML>" +
"<HEAD><TITLE>Not Found</TITLE></HEAD>" +
"<BODY>Not Found</BODY></HTML>";
}
// Send the status line.
try {
if (b) {
os.writeBytes(statusLine);
// Send the content type line.
os.writeBytes(contentTypeLine);
// Send a blank line to indicate the end of the header lines.
os.writeBytes(CRLF);
}
// Send the entity body.
if (fileExists) {
sendBytes(fis, os);
fis.close();
} else {
os.writeBytes("File DNE: Content Not Found!");
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private static String contentType(String fileName) {
if(fileName.endsWith(".htm") || fileName.endsWith(".html")) {
return "text/html";
}
if(fileName.endsWith(".jpeg") || fileName.endsWith(".jpg")) {
return "image/jpeg";
}
if(fileName.endsWith(".gif")) {
return "image/gif";
}
if(fileName.endsWith(".png")) {
return "image/png";
}
if(fileName.endsWith(".js")) {
return "text/javascript";
}
if(fileName.endsWith(".css")) {
return "text/stylesheet";
}
return "application/octet-stream";
}
private static void sendBytes(FileInputStream fis, OutputStream os)
throws Exception {
// Construct a 1K buffer to hold bytes on their way to the socket.
byte[] buffer = new byte[1024];
int bytes = 0;
// Copy requested file into the socket's output stream.
while((bytes = fis.read(buffer)) != -1 ) {
os.write(buffer, 0, bytes);
}
}
private void JustHello(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Just Hello</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\nHello World\n</body>\n</html>");
out.flush();
}
private void JustPic(PrintWriter out) {
// TODO Auto-generated method stub
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Server: Bot");
// this blank line signals the end of the headers
out.println("");
out.flush();
// Send the HTML page
out.print("<!DOCTYPE html>\n<html>\n<head>\n<title>Just Pic</title>\n<meta charset=\"UTF-8\">\n</head>\n<body>\n<img src=\"/images/th.jpg\"/>\n</body>\n</html>");
out.flush();
}
}
查看响应以/ server开头的请求的if子句。 按照代码处理请求。 它将文件作为文件传输器返回。 所以这里的地址＆＃34; server / image.jpg＆＃34;将是您在java中进行常规编程时提供的地址。此地址来自项目的根目录。 提到这段代码必须有一个main才能使用该类。 这对我来说很完美。