本地Http服务

2021-05-29

字数统计:2.7k字阅读时长≈14分

安卓加载 assets 目录中的网页时，虽然可以用 file:///android_asset/ 实现，但是一些网页的资源却不能正常加载，解决方法建一个本地Http服务器来实现网页加载

下面直接贴代码

com\xl\webserver\WebServer.java

package com.xl.webserver;
import android.content.Context;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class WebServer
{
 /**
	 * 使用线程池，减少频繁创建线程的消耗。
	 * 线程池
	 */
 private ExecutorService mExecutorService = null;
 private ServerSocket mServerSocket;
 private int mPort = 0;
 private boolean mIsAlive = true;
 private Context context;
 
 public void startServer(Context context, int port)
	{
  this.context = context;
  mIsAlive = true;
  mPort = port;
  /**
		 * 创建缓存类型的线程池
		 */
  mExecutorService = Executors.newCachedThreadPool();
  mExecutorService.execute(new AcceptRunnable());
 }
 
 /**
	 * 服务器是否还活着
	 * @return
	 */
 public boolean isAlive()
	{
  return mIsAlive;
 }

 /**
	 * 等到所有的线程都处理完才关闭服务器
	 */
 public void shutdown()
	{
  try {
   if(mServerSocket!=null)
   mServerSocket.close();
  } catch (IOException e) {
   e.printStackTrace();
  }
  mIsAlive = false;
  if(mExecutorService!=null)
   mExecutorService.shutdown();
 }
 
 /**
	 * 立即关闭服务器，不会等到所有的线程都处理完。
	 * 
	 */
 public void shutdownNow()
	{
  try {
   if(mServerSocket!=null)
   mServerSocket.close();
  } catch (IOException e) {
   e.printStackTrace();
  }
  mIsAlive = false;
  if(mExecutorService!=null)
   mExecutorService.shutdownNow();
 }
 
 /**
	 * 用于执行接受客户端连接的线程
	 * 将接受客户端的操作也放入子线程中执行，这样就不会阻塞主线程。
	 */
 class AcceptRunnable implements Runnable
	{
  @Override
  public void run() {
   try
   {
    mServerSocket = new ServerSocket(mPort);
    System.out.println("Web Server startup on " + mPort);
    while (mIsAlive)
    {
     Socket socket = mServerSocket.accept();
     // 通过线程池的方式来处理客户的请求
     if(mIsAlive)
      mExecutorService.execute(new Processor(context, socket));
    }
   }
   catch (IOException e)
   {
    e.printStackTrace();
   }
  }
 }
}

com\xl\webserver\Processor.java

package com.xl.webserver;

import android.content.Context;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;

import folk.china.http.HTTPRequestException;
import folk.china.http.HTTPRequestHeader;

/**
 * 处理一个HTTP用户请求的线程类。
 */
public class Processor implements Runnable {
    private PrintStream out;
    private InputStream input;
    private Context context;
    /**
     * 默认的服务器存放访问内容的目录D:\eclipse3.4\workspace03
     */
    public static String WEB_ROOT = "/mnt/sdcard/www/";

    public Processor(Context context,Socket socket) {
    	this.context = context;
        try {
            input = socket.getInputStream();
            out = new PrintStream(socket.getOutputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void run() {
        try {
   /*
			String fileName = parse(input);
			readFile(fileName);
			*/
            try {
                HTTPRequestHeader header = HTTPRequestHeader.parse(input);
                System.out.println(header.toString());
                readAssetsFile(header.mLocalUrl);
            } catch (HTTPRequestException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 解析客户机发过的所有HTTP请求，如果是符合HTTP协议内容的， 就分析出客户机所要访问文件的名字，并且返回文件名。
     */
    public String parse(InputStream input) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(input));
        String inputContent = in.readLine();
        if (inputContent == null || inputContent.length() == 0) {
            sendError(400, "Client invoke error");
            return null;
        }
// 分析客户请求的HTTP信息，分析出到底想访问哪个文件，
// 发过来的HTTP请求应该是三部分。
        String request[] = inputContent.split(" ");
        if (request.length != 3) {
            sendError(400, "Client invoke error");
            return null;
        }
// 第一部分是请求的方法
        String method = request[0];
// 第二部分是请求的文件名
        String fileName = request[1];
// 第三部分是HTTP版本号
        String httpVersion = request[2];
        System.out.println("Method: " + method + ", file name: " + fileName + ", HTTP version: " + httpVersion);
        return fileName;
    }

    /**
     * 处理调用一个文件的请求
     */
    public void readFile(String fileName) throws IOException {
        File file_root = new File(Processor.WEB_ROOT, fileName);
        String filename = null;
        String content_type = "text";
        int start = 0;
        if ((start = fileName.indexOf('?')) > 0) filename = fileName.substring(0, start);
        else filename = fileName;
        File file = new File(Processor.WEB_ROOT + filename);
        if (file.isDirectory()) {
            file = new File(Processor.WEB_ROOT + filename, "index.html");
        }
        if (!file.isFile()) {
            sendError(404, file.getPath() + " File Not Found");
            return;
        }


// 把文件的内容读取到in对象中。
        InputStream in = new FileInputStream(file);
        byte content[] = new byte[(int) file.length()];
        in.read(content);
        out.println("HTTP/1.0 200 sendFile");
        if (file.getName().endsWith(".html"))
            content_type = "text/html; charset=UTF-8";
        else if (file.getName().endsWith(".png"))
            content_type = "image/png";
        out.println("Content-Type: " + content_type);

        out.println("Content-length: " + content.length);
        out.println();
        out.write(content);
        out.flush();
        out.close();
        in.close();
    }

 public void readAssetsFile(String fileName) throws IOException {
  String filename = null;
  String content_type = "text";
  int start = 0;
  if ((start = fileName.indexOf('?')) > 0) filename = fileName.substring(0, start);
  else filename = fileName;
//		File file = new File(Processor.WEB_ROOT + filename);
//		if (file.isDirectory()) {
//			file = new File(Processor.WEB_ROOT + filename, "index.html");
//		}
//		if (!file.isFile()) {
//			sendError(404, file.getPath() + " File Not Found");
//			return;
//		}


// 把文件的内容读取到in对象中。
        if(filename.startsWith("/")){
            filename = filename.substring(1);
        }
  InputStream in = context.getAssets().open(Processor.WEB_ROOT + filename);
  byte[] content = new byte[in.available()];
  in.read(content);
  out.println("HTTP/1.0 200 sendFile");
  if (filename.endsWith(".html"))
   content_type = "text/html; charset=UTF-8";
  else if (filename.endsWith(".png"))
   content_type = "image/png";
  out.println("Content-Type: " + content_type);

  out.println("Content-length: " + content.length);
  out.println();
  out.write(content);
  out.flush();
  out.close();
  in.close();
 }

    /**
     * 发送错误的信息
     */
    public void sendError(int errNum, String errMsg) {
        out.println("HTTP/1.0 " + errNum + " " + errMsg);
        out.println("Content-type:text/html");
        out.println();
        out.println("<html>");
        out.println("<meta content=&#39;text/html; charset=gb2312&#39; http-equiv=&#39;Content-Type&#39;/>");
        out.println("<head><title>Error " + errNum + "--" + errMsg + "</title></head>");
        out.println("<h1>" + errNum + " " + errMsg + "</h1>");
        out.println("</html>");
        out.println();
        out.flush();
        out.close();
        System.out.println(errNum + ",,,," + errMsg);
    }
}

folk\china\http\HTTPRequestException.java

package folk.china.http;

/**
 * HTTP请求异常
 * @author wangchen11
 *
 */
public class HTTPRequestException extends Exception {
 public HTTPRequestException(String string) {
  super(string);
 }

 private static final long serialVersionUID = 1L;
}

folk\china\http\HTTPRequestHeader.java

package folk.china.http;

import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

import folk.china.util.ByteBuffer;

/**
 * HTTP请求头
 * @author wangchen11
 *
 */
public class HTTPRequestHeader {
 // 请求类型，是GET还是POST.
 public String mRequestType = "";
 // 本地路径
 public String mLocalUrl = "";
 // HTTP版本
 public String mVersion = "";
 // 所有的Get参数
 public Map<String, String> mGetValues = new HashMap<String, String>();
 // 所有的Post参数
 public Map<String, String> mPostValues = new HashMap<String, String>();
 // 所有属性集合
 public Map<String, String> mProperty = new HashMap<String, String>();
 
 public static HTTPRequestHeader parse(InputStream inputStream) throws HTTPRequestException
	{
  return parse(inputStream,null);
 }
 
 /**
	 * 解析得出HTTP请求头
	 * @param inputStream
	 * @param charset 指定参数的字符集,null:使用默认字符集
	 * @return 解析好的HTTP头。
	 * @throws HTTPRequestException 如果解析时发生异常，将抛出此异常。
	 */
 @SuppressWarnings("resource")
 public static HTTPRequestHeader parse(InputStream inputStream, String charset) throws HTTPRequestException
	{
  HTTPRequestHeader header= new HTTPRequestHeader();
  /**
		 * 不要在这里关闭这个scanner！
		 */
  Scanner scanner = null;
  if(charset==null)
   scanner = new Scanner(inputStream);
  else
  {
   try {
    scanner = new Scanner(inputStream,charset);
   } catch (IllegalArgumentException e) {
    throw new HTTPRequestException("unsupport charset!");
   }
  }
  
  String line = null;
  if(scanner.hasNextLine())
  {
   line = scanner.nextLine();
   if(line.endsWith("\r"))
   {
    line = line.substring(0, line.length()-1);
   }
   
   String[]items = line.split(" ");
   if(items.length!=3)
    throw new HTTPRequestException("items.length!=3");
   //得到请求类型
   if( (!items[0].equals("GET")) && (!items[0].equals("POST")) )
    throw new HTTPRequestException("Request type not 'GET' or 'POST'!");
   header.mRequestType = items[0];
   
   //分离URL和GET参数
   int fristQMarkIndex = items[1].indexOf('?');
   if(fristQMarkIndex==-1)
   {
    header.mLocalUrl = items[1];
   }
   else
   {
    header.mLocalUrl = items[1].substring(0, fristQMarkIndex);
    header.mGetValues.putAll(
      getParamByString( items[1].substring(fristQMarkIndex+1,items[1].length()),charset ));
   }
   header.mVersion = items[2];
  }
  
  /**
		 * 碰到空行，如果是GET请求就立即停止解析，如果是POST请求就只读下一行所有内容，下一行内容都是POST的参数。
		 */
  while(scanner.hasNextLine())
  {
   line = scanner.nextLine();
   if(line.endsWith("\r"))
   {
    line = line.substring(0, line.length()-1);
   }
   
   if(lineIsEmpty(line))
   {
    if(header.mRequestType.equals("POST"))
    {
     if(scanner.hasNextLine())
      header.mPostValues.putAll(getParamByString(scanner.nextLine(),charset));
    }
    break;
   }
   
   int fristColonIndex = line.indexOf(":");
   if(fristColonIndex==-1)
   {
    throw new HTTPRequestException("line:"+line+" no expected ':'");
   }
   else
   {
    String name = line.substring(0, fristColonIndex);
    String value = line.substring(fristColonIndex+1);
    if(value.startsWith(" "))
     value = value.substring(1);
    header.mProperty.put(name,value);
   }
  }
  
  return header;
 }
 
 private static Map<String, String> getParamByString(String str, String charset) throws HTTPRequestException
	{
  Map<String, String> map = new HashMap<String, String>();
  String[]params = str.split("&");
  for(String param : params)
  {
   int fristEqualIndex = param.indexOf('=');
   if(fristEqualIndex==-1)
   {
    // throw new HTTPRequestException("params  is not valid!");
    // ignore it 
    continue;
   }
   String name = param.substring(0, fristEqualIndex);
   String value = param.substring(fristEqualIndex+1);
   map.put(name, getTranslatedValue(value,charset) );
  }
  return map;
 }
 
 /**
	 * 判断一行是否除了 空格 \r \t 没有其它字符了
	 * @param line
	 * @return
	 */
 private static boolean lineIsEmpty(String line)
	{
  int len = line.length();
  for(int i=0;i<len;i++)
  {
   char ch = line.charAt(i);
   switch (ch) {
   case ' ':
   case '\r':
   case '\t':
    break;
   default:
    return false;
   }
  }
  return true;
 }
 
 /**
	 * 得到翻译后的参数
	 * @param value 翻译前的参数
	 * @param charset 字符集
	 * @return
	 * @throws HTTPRequestException
	 */
 private static String getTranslatedValue(String value, String charset) throws HTTPRequestException
	{
  StringBuilder builder = new StringBuilder();
  ByteBuffer byteBuffer = new ByteBuffer();
  int len = value.length();
  for(int i=0;i<len;i++)
  {
   char ch = value.charAt(i);
   if(ch=='%')
   {//后跟最多两位的十六进制数
    int onebyte = 0;
    if(i+2>=len)
    {
     continue;
    }
    else
    {
     int halfByte = getHexChar(value.charAt(i+1));
     onebyte = halfByte&0x0f;
     if(halfByte==-1)
     {
      continue;
     }
     else
     {
      i++;
      halfByte = getHexChar(value.charAt(i+1));
      if(halfByte==-1)
      {
      }
      else
      {
       i++;
       onebyte = (onebyte<<4)|(halfByte&0x0f);
      }
      byteBuffer.put((byte)onebyte);
     }
     
    }
   }
   else
   {
    if(byteBuffer.length()>0)
    {
     if(charset==null)
     {
      builder.append(new String(byteBuffer.getBytes(), 0, byteBuffer.length()));
     }
     else
     {
      try {
       builder.append(new String(byteBuffer.getBytes(), 0, byteBuffer.length(),charset));
      } catch (UnsupportedEncodingException e) {
       throw new HTTPRequestException("UnsupportedEncodingException:"+e.getMessage());
      }
     }
     byteBuffer.clear();
    }
    builder.append(ch);
   }
  }
  
  if(byteBuffer.length()>0)
  {
   if(charset==null)
   {
    builder.append(new String(byteBuffer.getBytes(), 0, byteBuffer.length()));
   }
   else
   {
    try {
     builder.append(new String(byteBuffer.getBytes(), 0, byteBuffer.length(),charset));
    } catch (UnsupportedEncodingException e) {
     throw new HTTPRequestException("UnsupportedEncodingException:"+e.getMessage());
    }
   }
   byteBuffer.clear();
  }
  
  return builder.toString();
 }
 
 public static int getHexChar(char ch)
	{
  int halfByte = -1;
  if(ch>='0'&&ch<='9')
   halfByte = ch-'0';
  if(ch>='a'&&ch<='f')
   halfByte = ch-'a'+10;
  if(ch>='A'&&ch<='F')
   halfByte = ch-'A'+10;
  return halfByte;
 }
 
 @Override
 public String toString() {
  StringBuilder stringBuilder = new StringBuilder();
  stringBuilder.append(""+mRequestType+" "+mLocalUrl+"?"+mGetValues.toString()+" "+mVersion);
  stringBuilder.append("\r\n");
  if(mPostValues.size()>0)
  {
   stringBuilder.append(""+mPostValues.toString());
   stringBuilder.append("\r\n");
  }
  stringBuilder.append(""+mProperty.toString());
  stringBuilder.append("\r\n");
  stringBuilder.append("\r\n");
  return stringBuilder.toString();
 }
}

/*
GET / HTTP/1.1
Host: 127.0.0.1:8080
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,* /*;q=0.8
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36
Accept-Encoding: gzip, deflate, sdch
Accept-Language: zh-CN,zh;q=0.8
Cookie: _ga=GA1.1.1885384815.1467970825


POST / HTTP/1.1
Host: 127.0.0.1:8080
Connection: keep-alive
Content-Length: 10
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,* /*;q=0.8
Origin: null
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.8
Cookie: _ga=GA1.1.1885384815.1467970825

name=value

（注:* /*,为了避开注释的结束符，多加了一个空格）。
*/

folk\china\util\ByteBuffer.java

package folk.china.util;

/**
 * 可无限制增长的字节缓冲区
 * @author wangchen11
 *
 */
public class ByteBuffer {
 //默认起始缓冲区长度
 public static final int DEFAULT_START_SIZE = 64;
 //默认每次增加缓冲区的长度
 public static final int DEFAULT_STEP_SIZE = 512; 
 private byte []mBuffer = null;
 private int mPos = 0;
 private int mStepSize = 0;

 public ByteBuffer() {
  this(DEFAULT_START_SIZE);
 }

 public ByteBuffer(int startSize) {
  this(startSize,DEFAULT_STEP_SIZE);
 }

 public ByteBuffer(int startSize,int stepSize) {
  setRealSize(startSize);
  setStepSize(stepSize);
 }
 
 public void setStepSize(int stepSize)
	{
  if(stepSize<1)
   stepSize=1;
  mStepSize = stepSize;
 }
 
 public void put(byte data)
	{
  checkSize(mPos+1);
  mBuffer[mPos]=data;
  mPos++;
 }
 
 public void put(byte []data)
	{
  put(data,0,data.length);
 }
 
 public void put(byte []data,int offset,int count)
	{
  checkSize(mPos+count);
  System.arraycopy(data, offset, mBuffer, mPos, count);
  mPos+=count;
 }
 
 private void checkSize(int needSize)
	{
  if(needSize>mBuffer.length)
  {
   setRealSize( needSize + mStepSize );
  }
 }
 
 
 private void setRealSize(int realSize)
	{
  byte []tempBuffer = new byte[realSize];
  if(mBuffer!=null)
  {
   System.arraycopy(mBuffer, 0, tempBuffer, 0, mPos);
  }
  mBuffer = tempBuffer;
 }
 
 public void clear()
	{
  mPos = 0;
 }
 
 public int length()
	{
  return mPos;
 }
 
 public byte[] getBytes()
 {
  return mBuffer;
 }
}

需要加载assets中的网页时只需要

1
2
3

Processor.WEB_ROOT = "";
WebServer server = new WebServer();
server.startServer(this, 8080);

在WebView中加载 http://localhost:8080/index.html 即可

若需要加载文件中的网页文件需要在 Processor.java 中将 readAssetsFile() 改到 readFile() ,将 WEB_ROOT 指定为网页路径即可

在高版本安卓上还要开启允许Http访问

上面方法来自fengdeyingzi/egretAndroid