AspectJ截获操作

package com.example.aspectjandroidtest;



import java.io.BufferedOutputStream;

import java.io.ByteArrayOutputStream;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.UnsupportedEncodingException;



import org.apache.http.util.EncodingUtils;



import com.facebook.crypto.Crypto;

import com.facebook.crypto.Entity;

import com.facebook.crypto.keychain.SharedPrefsBackedKeyChain;

import com.facebook.crypto.util.SystemNativeCryptoLibrary;



public aspect FileAspectJ {



	private boolean isEncryption = true;

	//使用秘钥链和原生库的默认实现，来创建一个新的加密对象

	Crypto crypto = new Crypto(

			new SharedPrefsBackedKeyChain(MainActivity.context), 

			new SystemNativeCryptoLibrary());

	

	//创建应用文件的切点集合

	pointcut openFileOutput(String filename,int mode) : !within(FileAspectJ) && args(filename,mode) && call(* openFileOutput(..));

	after (String filename,int mode) returning : openFileOutput(filename, mode){

		//System.out.println("fx Aspectj openFile is start");

		byte[] buffer;

		try {

			System.out.println("fx Aspectj openFileName"+filename);

			buffer = filename.getBytes("UTF8");

			FileOutputStream fileOutputStream = null;

			try {

				//记录本应用加密过的文件

				fileOutputStream = MainActivity.context.openFileOutput("fileList",

						MainActivity.context.MODE_APPEND);

			} catch (FileNotFoundException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

			try {

				fileOutputStream.write(buffer);

				fileOutputStream.close();

			} catch (IOException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		} catch (UnsupportedEncodingException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

	

	//读取应用文件的切点集合

		pointcut openFileInput(String filename) : !within(FileAspectJ) && args(filename) && call(* openFileInput(..));

		before(String filename) : openFileInput(filename){

			

			String result = "";

			try {

				FileInputStream fileInputStream = MainActivity.context.openFileInput("fileList");

				int bufferSize = 0;

				try {

					bufferSize = fileInputStream.available();

				} catch (IOException e) {

					// TODO Auto-generated catch block

					e.printStackTrace();

				} // 取得输入流的字节长度

				byte buffer[] = new byte[bufferSize];

				try {

					fileInputStream.read(buffer);

					fileInputStream.close();

				} catch (IOException e) {

					// TODO Auto-generated catch block

					e.printStackTrace();

				}

				result = EncodingUtils.getString(buffer, "UTF-8");

			} catch (FileNotFoundException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

			//判断文件是否加密过

			if(result.indexOf(filename) == -1){

				isEncryption = false;//未加密

				System.out.println("fx 文件未加密");

			}else{ 

				isEncryption = true;//已加密

				System.out.println("fx 文件已加密");

			}

		}

	

		//截获到File的new操作

		pointcut filePointcut(String pathname ) :  !within(FileAspectJ) && args(pathname) && call(java.io.File.new(..));

		before(String pathname ) : filePointcut(pathname) {

			System.out.println("fx pathname is " + pathname);

		}

		

	//写文件切点的集合

	pointcut writePointcut(FileOutputStream fileStream, byte[] buffer) : !within(FileAspectJ) && target(fileStream)&& args(buffer) && call(* write(..));

	void around(FileOutputStream fileStream, byte[] buffer) : writePointcut(fileStream, buffer) {

		System.out.println("fx Aspectj write is start");

		//检查加密功能是否可用

		//如果Android没有正确载入库，则此步骤可能失败

		if (!crypto.isAvailable()) {

			System.out.println("return error");

			return;

		}

		OutputStream fbFileStream = new BufferedOutputStream(fileStream);

		try {

			//创建输出流，当数据写入流的时候进行加密，并将加密后的数据输出到文件

			OutputStream outputStream = crypto.getCipherOutputStream(

					fbFileStream, new Entity("test"));

			outputStream.write(buffer);

			outputStream.close();

		} catch (Exception e) {

			e.printStackTrace();

		}

	}



	//读文件切点集合

	pointcut readPointcut(FileInputStream fileStream, byte[] buffer) : !within(FileAspectJ) && target(fileStream)&& args(buffer) && call(* read(..));

	int around(FileInputStream fileStream, byte[] buffer) : readPointcut(fileStream, buffer) {

		System.out.println("fx Aspectj read is start");

		int bufferSize = 0;

		if(isEncryption==false){

			return 0;

		}

		try {

			//文件流解密操作

			InputStream inputStream = crypto.getCipherInputStream(fileStream,	new Entity("test"));

			bufferSize = inputStream.available(); // 取得输入流的字节长度

			ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

	        byte[] data = new byte[1024];

			int len;

			 if (inputStream != null) {

		            try {

		                while ((len = inputStream.read(data)) != -1) {

		                    outputStream.write(data, 0, len);

		                }

		                data = outputStream.toByteArray();

		            } catch (IOException e) {

		            }

		        }

			 for(int i = 0;i<data.length;i++) {

				 buffer[i] = data[i];

			 }

			inputStream.close();

			outputStream.close();

		} catch (Exception e) {

			e.printStackTrace();

		}



		return bufferSize;

	}



}