JAVA實現簡易HTTP伺服器
說實話,之前完全沒有想過,我還能寫出伺服器。感覺伺服器這麼高階的東西,能會用就不錯了,還能寫。
不吐槽了,開始了。
這次的作業是搭建一個伺服器,要能接收請求,並給瀏覽器返回正確響應。
專案的下載地址
專案目標:實現一個簡易的多執行緒伺服器,可以處理來自瀏覽器的請求(GET/POST),並做出正確的迴應。
請求分以下四種類型:
1. 無引數,文字檔案型別
2. 無引數,圖片檔案型別
3. 有引數,GET方式請求,並完成表單驗證(登陸驗證)
4. 有引數,POST方式請求,並完成表單驗證(登陸驗證)
首先,應該明確這個專案的基本實現原理,從瀏覽器讀入使用者請求的資訊,伺服器解析並記錄返回的檔名和引數列表,如果檔案存在,用流讀取檔案,並返回到瀏覽器上,如果不存在,返回相應的提示資訊,引數列表和伺服器儲存的相同的話,返回登陸成功,否則返回失敗。
第一步,既然要解析從瀏覽器傳過來的資訊,那就要明白傳過來資訊的所使用的協議HTTP\UDP\FTP 和 URL的組成元素,因為是簡易伺服器,我們就只解析HTTP協議先。
Request是指從客戶端到伺服器端的請求訊息
Request 訊息分為3部分,第一部分叫請求行, 第二部分叫http header, 第三部分是body. header和body之間有個空行,結構如下圖
Method表示請求方法,比如”POST”,”GET”,
Path-to-resoure表示請求的資源,
Http/version-number 表示HTTP協議的版本號,
當使用的是”GET” 方法的時候, body是為空的,當使用”POST”,body不為空,但是沒有換行,readline()方法不能讀
Response是指伺服器端到客戶端的響應資訊
和Request訊息的結構基本一樣。 同樣也分為三部分,第一部分叫request line, 第二部分叫request header,第三部分是body. header和body之間也有個空行, 結構如下圖
狀態碼用來告訴HTTP客戶端,HTTP伺服器是否產生了預期的Response. HTTP/1.1中定義了5類狀態碼,1XX 提示資訊 - 表示請求已被成功接收,繼續處理;2XX 成功 - 表示請求已被成功接收,理解,接受;3XX 重定向 - 要完成請求必須進行更進一步的處理;4XX 客戶端錯誤 - 請求有語法錯誤或請求無法實現;5XX 伺服器端錯誤 - 伺服器未能實現合法的請求,當然不寫也是可以得,狀態碼就是便於程式設計師去分析當前頁面是正確響應還是錯誤的。
第二步,在瞭解URL和HTTP協議之後,就可以開始構建專案了。
目前這個專案的UML圖
第三步,準備文字、圖片、HTML檔案,然後開始編編編
效果圖:(埠號:23333)2333…
預設訪問
aaron.txt
a.jpg
GET/POST請求
注意位址列的變化
login.html(GET)
login.html(GET) (登陸失敗情況)
login.html(GET) (登陸成功情況)
login.html(POST)
login.html(POST) (登陸失敗情況)
login.html(POST) (登陸成功情況)
部分原始碼:(全部原始碼去上面下載)
//Server.java
package cn.net.sight.server;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Properties;
import cn.net.sight.thread.ServerThread;
public class Server {
private static ServerSocket server;
private static Properties properties;
private int port;
static {
properties = new Properties();
try {
properties.load(new FileInputStream(new File("src/resources/property.proterties")));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
//initialize the server
public void init() {
try {
port = Integer.parseInt(properties.getProperty("port"));
server = new ServerSocket(port);
} catch (IOException e) {
e.printStackTrace();
}
}
//receive the request from the web browser
public void receive() {
Socket clientSocket = new Socket();
try {
clientSocket = server.accept();
} catch (IOException e) {
e.printStackTrace();
}
ServerThread thread = new ServerThread(clientSocket);
thread.start();
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//startup server
public static void main(String[] args) {
Server Aaroncat = new Server();
Aaroncat.init();
System.out.println("----Aaroncat has startup----");
while(true){
Aaroncat.receive();
}
}
}
//Request.java
package cn.net.sight.server;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.util.HashMap;
import java.util.Map;
import cn.net.sight.util.MessageUtil;
public class Request {
private InputStream input; // Socket --> InputStream
private Socket socket; // client --> socket
private BufferedReader buffer; // InputStream --> BufferedReader
private String schema; // the schema of the request GET or POST
private String requestFileName; // exact file name
private String requestData; // file name + <key=value>...
private String values_Str; // a string the user input in the form
private int paramLength; // using in the POST: the length of parameters
private Map<String, String> socketValues;// values_str --> MAP
private PrintStream print;
protected MessageUtil messageUtil = new MessageUtil();
//省略了全部的setter() getter()
private void doSchema(String firstLineInData) throws IOException {
socketValues = new HashMap<String, String>();
if (this.schema.equals("GET")) {
// GET請求 --> 包含檔名和引數鍵值對
// 實現了對FileName、SocketValues的賦值
this.setRequestData(messageUtil.getRequestData(firstLineInData));
if (this.requestData.contains("?")) {
this.setRequestFileName(messageUtil.getFileName(this.getRequestData()));
this.setSocketValues(messageUtil.getValues(this.getRequestData()));
} else {
// GET請求 -->只包含檔名
// 實現了對FileName的賦值
this.setRequestFileName(requestData);
}
} else {
// POST請求 第一行只包含檔名
// 實現了對FileName、SocketValues的賦值
this.setRequestFileName(messageUtil.getRequestData(firstLineInData));
this.getUserInfo(buffer);
}
}
private void getUserInfo(BufferedReader br) throws IOException {
while (this.buffer.ready()) {
String remained = buffer.readLine();
if (remained.contains("Content-Length")) {
String[] temp = remained.split(" ");
this.setParamLength(Integer.parseInt(temp[1]));
break;
}
}
buffer.readLine();
String userInfo = "";
for (int i = 0; i < this.getParamLength(); i++) {
userInfo += (char) buffer.read();
}
this.setValues_Str(userInfo);
this.setSocketValues(messageUtil.getValues(this.getValues_Str()));
}
public Request(Socket clientSocket) throws IOException {
this.setSocket(clientSocket);
this.setPrint(new PrintStream(clientSocket.getOutputStream()));
this.setInput(clientSocket.getInputStream());
this.setBuffer(new BufferedReader(new InputStreamReader(clientSocket.getInputStream())));
// get something from the first line
String firstLineInData = buffer.readLine();
this.setSchema(messageUtil.getSchema(firstLineInData)); // 獲得請求方式Schema
doSchema(firstLineInData); // 對Schema進行判斷
}
}
//Response.java
package cn.net.sight.server;
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Date;
import java.util.Map;
import cn.net.sight.util.FileUtil;
import cn.net.sight.util.LoginUtil;
public class Response {
private String fileName;
private Map<String, String> userValues;
private PrintStream ps;
private Request request;
private Socket clientSocket;
protected FileUtil fileUtil = new FileUtil();
protected LoginUtil loginUtil = new LoginUtil();
public String getFileName() {
return fileName;
}
//省略了全部的setter() 和 getter()
public Response(Request request) {
this.setRequest(request);
this.setClientSocket(request.getSocket());
this.setFileName(request.getRequestFileName());
userValues = this.request.getSocketValues();
try {
this.init();
} catch (IOException e) {
e.printStackTrace();
}
}
public void showup(String fileName) throws IOException {
this.ps = this.request.getPrint();
// 要處理正常檔名和空檔名
if (!fileName.equals("") && !fileName.equals("error.html")) {
this.ps.println("HTTP/1.1 200 OK");
this.ps.println();
fileUtil.readFile(fileName, ps);
} else if (fileName.equals("error.html")) {
ps.println("HTTP/1.1 404 fileNotFound");
ps.println();
fileUtil.readFile("error.html", ps);
} else {
ps.println(new Date().toString());
}
if (ps != null){
ps.close();
}
}
public void init() throws IOException {
//如果資訊MAP是空,則代表是普通檔案或者是預設訪問
if (userValues.isEmpty()) {
if (fileName != "") {
this.showup(fileName);
} else {
this.ps = this.request.getPrint();
ps.println(new Date().toString());
if(ps != null) ps.close();
if(clientSocket != null)clientSocket.close();
}
} else {
//如果資訊MAP不為空,代表是GET/POST請求,並帶有引數鍵值對
this.Check(userValues, fileName);
}
}
public void Check(Map<String, String> values_list, String respFileName) throws IOException {
// 驗證使用者輸入資訊的合法性
if (loginUtil.isValid(values_list)) {
this.showup(respFileName);
} else {
this.showup("error.html");
}
}
}
//ServerThread.java
package cn.net.sight.thread;
import java.io.IOException;
import java.net.Socket;
import cn.net.sight.server.Response;
import cn.net.sight.server.Request;
public class ServerThread extends Thread {
private Socket clientSocket;
private Request request;
private Response response;
public ServerThread() {
super();
}
public ServerThread(Socket clientSocket) {
super();
this.clientSocket = clientSocket;
}
public Socket getClientSocket() {
return clientSocket;
}
public void setClientSocket(Socket clientSocket) {
this.clientSocket = clientSocket;
}
public Request getRequest() {
return request;
}
public void setRequest(Request request) {
this.request = request;
}
public Response getResponse() {
return response;
}
public void setResponse(Response response) {
this.response = response;
}
public void run(){
super.run();
try {
this.setRequest(new Request(clientSocket));
this.response = new Response(request);
this.setResponse(response);
} catch (IOException e) {
e.printStackTrace();
}
}
}
//FileUtil.java
package cn.net.sight.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintStream;
public class FileUtil {
private static final int BUFFER_SIZE = 1024;
public void readFile(String file_Name, PrintStream ps) throws IOException {
byte[] buffer = new byte[BUFFER_SIZE];
int length;
File file = new File("src/resources/" + file_Name);
FileInputStream fis = null;
if (file.exists()) {
try {
fis = new FileInputStream(file);
while ((length = fis.read(buffer)) != -1) {
ps.write(buffer, 0, length);
ps.flush();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
} else {
ps.println("File not found");
ps.println();
}
}
}
//LoginUtil.java
package cn.net.sight.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Map;
import java.util.Properties;
public class LoginUtil {
protected boolean flag = false;
protected Map<String, String> values;
private static Properties properties;
static {
properties = new Properties();
try {
properties.load(new FileInputStream(new File("src/resources/property.proterties")));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public boolean isFlag() {
return flag;
}
public void setFlag(boolean flag) {
this.flag = flag;
}
public Map<String, String> getValues() {
return values;
}
public void setValues(Map<String, String> values) {
this.values = values;
}
// 驗證使用者資訊的合法性(應用JDBC橋,連線資料庫)
public boolean isValid(Map<String, String> values) {
String username = properties.getProperty("username");
String password = properties.getProperty("password");
if (values.get("username").equals(username)) {
if (values.get("password").equals(password)) {
flag = true;
System.out.println("The user " + values.get("username") + " was log the server.");
return flag;
}
} else {
System.out.println("Forbide the " + values.get("username") + " log the server");
return flag;
}
return false;
}
}
//MessageUtil.java
package cn.net.sight.util;
import java.util.HashMap;
import java.util.Map;
public class MessageUtil {
// schema : GET or POST
public String getSchema(String requestMsg) {
String[] result = new String[1];
if (requestMsg.contains(" ")) {
result = requestMsg.split(" ");
requestMsg = result[0];
}
return requestMsg;
}
// get the resquestData = (filename + map<S,S>)
public String getRequestData(String firstLineInData) {
String[] result = new String[10];
result = firstLineInData.split(" ");
firstLineInData = result[1].substring(1);
return firstLineInData;
}
// get the filename from the requestData
public String getFileName(String requestData) {
String[] result = new String[10];
result = requestData.split("[?]");
return result[0];
}
// save the info into the map<S,S>
public Map<String, String> getValues(String requestData) {
Map<String, String> values = new HashMap<String, String>();
String[] result = new String[10];
String regex = "[&=]";
if (requestData.contains("?")) {
result = requestData.split("[?]");
String data_List = result[1];
result = data_List.split(regex);
for (int i = 0; i < result.length - 1; i += 2) {
values.put(result[i], result[i + 1]);
}
return values;
} else {
result = requestData.split(regex);
for (int i = 0; i < result.length - 1; i += 2) {
values.put(result[i], result[i + 1]);
}
return values;
}
}
}
整個專案結構