Showing posts with label oauth2. Show all posts
Showing posts with label oauth2. Show all posts

Monday, November 21, 2016

Java read email from google using oauth2 and parse email

Read Email From Google Account


package com.google_api;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * Created by pritom on 21/11/2016.
 */
public class JavaReadEmail extends JavaRawEmailParser {
    public static void main(String[] args) throws Exception {
        String accessToken = getAccessToken();
        String userID = "118224582562607576118"; /* From google profile */
        String messageID = "158855e85a035ed1";
        String url = "https://www.googleapis.com/gmail/v1/users/";
        url += userID + "/messages/" + messageID + "?format=raw";
        url += "&access_token=" + accessToken;

        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        connection.setRequestMethod("GET");
        connection.setRequestProperty("Content-Type", "application/json");

        int httpCode = connection.getResponseCode();
        String responseMessage = connection.getResponseMessage(), httpResponse = "";
        InputStream is = null;
        if (httpCode >= 200 && httpCode <= 299) {
            is = connection.getInputStream();
        }
        else {
            is = connection.getErrorStream();
        }

        Writer writer5 = new StringWriter();
        char[] buffer = new char[1024];
        Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
        int n;
        while ((n = reader.read(buffer)) != -1) {
            writer5.write(buffer, 0, n);
        }
        httpResponse = writer5.toString();
        println(httpResponse);

        String snippet = httpResponse.substring(httpResponse.indexOf("\"snippet\":") + 12);
        snippet = snippet.substring(0, snippet.indexOf("\n") - 2).trim();
        println("Snippet=" + snippet);

        String raw = httpResponse.substring(httpResponse.indexOf("\"raw\":") + 8);
        raw = raw.substring(0, raw.indexOf("\n") - 2).trim();

        parse(raw);
    }

    private static String getAccessToken() throws Exception {
        return "return access token from google";
    }
}

Parse Email Received From Google Account


package com.google_api;

import javax.mail.*;
import javax.mail.internet.MimeMessage;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.FileWriter;
import java.io.InputStream;
import java.util.*;

/**
 * Created by pritom on 20/11/2016.
 */
public class JavaRawEmailParser {
    private static final String ENCODING = "UTF-8";

    public static void parse(String rawEmail) throws Exception {
        rawEmail = Base64Decoder.decodeBase64(rawEmail);
        Session s = Session.getDefaultInstance(new Properties());
        InputStream is = new ByteArrayInputStream(rawEmail.getBytes(ENCODING));
        MimeMessage mimeMessage = new MimeMessage(s, is);
        Enumeration enumeration = mimeMessage.getAllHeaders();
        while (enumeration.hasMoreElements()) {
            Header header = (Header) enumeration.nextElement();
            if (!header.getName().contains("Received")) {
                println(header.getName() + " == " + toSingleLine(header.getValue()));
            }
        }
        Map output = processMultipart((Multipart) mimeMessage.getContent());
        for (Object key : output.keySet().toArray()) {
            println("Key=<<" + key + ">> == " + output.get(key));
        }
    }

    private static Map processMultipart(Multipart multipart) throws Exception {
        Map output = new HashMap();
        output.put("html", "");
        output.put("text", "");
        List attachments = new ArrayList();

        for(int i = 0; i < multipart.getCount(); i++) {
            Map result = processBodyPart(multipart.getBodyPart(i));
            if (result != null) {
                if (result.containsKey("type")) {
                    if (result.get("type").toString().equalsIgnoreCase("html")) {
                        output.put("html", result.get("content").toString());
                    }
                    else if (result.get("type").toString().equalsIgnoreCase("text")) {
                        output.put("text", result.get("content").toString());
                    }
                    else if (result.get("type").toString().equalsIgnoreCase("attachment")) {
                        attachments.add(result);
                    }
                }
                if (result.containsKey("html")) {
                    output.put("html", result.get("html").toString());
                }
                if (result.containsKey("text")) {
                    output.put("text", result.get("text").toString());
                }
                if (result.containsKey("attachments")) {
                    List thisAttachments = (List) result.get("attachments");
                    for (int i2 = 0; i2 < thisAttachments.size(); i2++) {
                        attachments.add(thisAttachments.get(i2));
                    }
                }
            }
        }
        output.put("attachments", attachments);

        return output;
    }

    private static Map processBodyPart(BodyPart bodyPart) throws Exception {
        if(bodyPart.isMimeType("text/html") && bodyPart.getFileName() == null) {
            Map data = new HashMap();
            data.put("type", "html");
            data.put("content", bodyPart.getContent().toString());
            return data;
        }
        else if(bodyPart.isMimeType("text/plain") && bodyPart.getFileName() == null) {
            Map data = new HashMap();
            data.put("type", "text");
            data.put("content", bodyPart.getContent().toString());
            return data;
        }
        else if(Part.ATTACHMENT.equalsIgnoreCase(bodyPart.getDisposition()) && bodyPart.getFileName() != null) {
            Map map = new HashMap();
            map.put("type", "attachment");
            map.put("fileName", bodyPart.getFileName());
            map.put("fileType", bodyPart.getContentType().substring(0, bodyPart.getContentType().indexOf(";")));
            map.put("mimeBodyPart", bodyPart);
            return map;
        }
        else if(bodyPart.getContentType().contains("multipart")) {
            Map o = processMultipart((Multipart) bodyPart.getContent());
            return o;
        }
        return null;
    }

    private static String toSingleLine(String str) throws Exception {
        return str.replaceAll("\\s+", " ");
    }

    private static void writeToFile(String location, String content) throws Exception {
        BufferedWriter out = new BufferedWriter(new FileWriter(location));
        out.write(content);
        out.close();
    }

    protected static void println(Object o) {
        System.out.println("" + o);
    }
}

Decode Util Class


package com.google_api;

/**
 * Created by pritom on 20/11/2016.
 */
public class Base64Decoder {
    private static final String ENCODING = "UTF-8";
    private static final byte[] CHUNK_SEPARATOR = new byte[]{(byte)13, (byte)10};
    private static final byte[] DECODE_TABLE = new byte[]{
            (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)62, (byte)-1, (byte)62, (byte)-1, (byte)63, (byte)52, (byte)53,
            (byte)54, (byte)55, (byte)56, (byte)57, (byte)58, (byte)59, (byte)60, (byte)61, (byte)-1, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)-1, (byte)0, (byte)1, (byte)2, (byte)3, (byte)4, (byte)5,
            (byte)6, (byte)7, (byte)8, (byte)9, (byte)10, (byte)11, (byte)12, (byte)13, (byte)14, (byte)15, (byte)16,
            (byte)17, (byte)18, (byte)19, (byte)20, (byte)21, (byte)22, (byte)23, (byte)24, (byte)25, (byte)-1,
            (byte)-1, (byte)-1, (byte)-1, (byte)63, (byte)-1, (byte)26, (byte)27, (byte)28, (byte)29, (byte)30,
            (byte)31, (byte)32, (byte)33, (byte)34, (byte)35, (byte)36, (byte)37, (byte)38, (byte)39, (byte)40,
            (byte)41, (byte)42, (byte)43, (byte)44, (byte)45, (byte)46, (byte)47, (byte)48, (byte)49, (byte)50, (byte)51};
    private final byte[] decodeTable;
    private final int decodeSize;
    private int bitWorkArea;
    private byte[] buffer;
    private int pos;
    private int readPos;
    private boolean eof;
    private int modulus;

    public static String decodeBase64(String raw) throws Exception {
        return new String(new Base64Decoder(0, CHUNK_SEPARATOR).decode(raw), ENCODING);
    }

    private Base64Decoder(int lineLength, byte[] lineSeparator) throws Exception {
        super();
        this.decodeTable = DECODE_TABLE;
        int encodeSize;
        if(lineSeparator != null) {
            if(this.containsAlphabetOrPad(lineSeparator)) {
                String sep = newStringUtf8(lineSeparator);
                throw new Exception("lineSeparator must not contain base64 characters: [" + sep + "]");
            }

            if(lineLength > 0) {
                encodeSize = 4 + lineSeparator.length;
                System.arraycopy(lineSeparator, 0, new byte[lineSeparator.length], 0, lineSeparator.length);
            } else {
                encodeSize = 4;
            }
        } else {
            encodeSize = 4;
        }

        this.decodeSize = encodeSize - 1;
    }

    private void decode(byte[] in, int inPos, int inAvail) {
        if(!this.eof) {
            if(inAvail < 0) {
                this.eof = true;
            }

            for(int i = 0; i < inAvail; ++i) {
                this.ensureBufferSize(this.decodeSize);
                byte b = in[inPos++];
                if(b == 61) {
                    this.eof = true;
                    break;
                }

                if(b >= 0 && b < DECODE_TABLE.length) {
                    byte result = DECODE_TABLE[b];
                    if(result >= 0) {
                        this.modulus = (this.modulus + 1) % 4;
                        this.bitWorkArea = (this.bitWorkArea << 6) + result;
                        if(this.modulus == 0) {
                            this.buffer[this.pos++] = (byte)(this.bitWorkArea >> 16 & 255);
                            this.buffer[this.pos++] = (byte)(this.bitWorkArea >> 8 & 255);
                            this.buffer[this.pos++] = (byte)(this.bitWorkArea & 255);
                        }
                    }
                }
            }

            if(this.eof && this.modulus != 0) {
                this.ensureBufferSize(this.decodeSize);
                switch(this.modulus) {
                    case 2:
                        this.bitWorkArea >>= 4;
                        this.buffer[this.pos++] = (byte)(this.bitWorkArea & 255);
                        break;
                    case 3:
                        this.bitWorkArea >>= 2;
                        this.buffer[this.pos++] = (byte)(this.bitWorkArea >> 8 & 255);
                        this.buffer[this.pos++] = (byte)(this.bitWorkArea & 255);
                }
            }

        }
    }

    private boolean isInAlphabet(byte octet) {
        return octet >= 0 && octet < this.decodeTable.length && this.decodeTable[octet] != -1;
    }

    private int available() {
        return this.buffer != null ? this.pos - this.readPos : 0;
    }

    private int getDefaultBufferSize() {
        return 8192;
    }

    private void resizeBuffer() {
        if(this.buffer == null) {
            this.buffer = new byte[this.getDefaultBufferSize()];
            this.pos = 0;
            this.readPos = 0;
        }
        else {
            byte[] b = new byte[this.buffer.length * 2];
            System.arraycopy(this.buffer, 0, b, 0, this.buffer.length);
            this.buffer = b;
        }
    }

    private void ensureBufferSize(int size) {
        if(this.buffer == null || this.buffer.length < this.pos + size) {
            this.resizeBuffer();
        }

    }

    private int readResults(byte[] b, int bPos, int bAvail) {
        if(this.buffer != null) {
            int len = Math.min(this.available(), bAvail);
            System.arraycopy(this.buffer, this.readPos, b, bPos, len);
            this.readPos += len;
            if(this.readPos >= this.pos) {
                this.buffer = null;
            }
            return len;
        }
        else {
            return this.eof ? -1 : 0;
        }
    }

    private void reset() {
        this.buffer = null;
        this.pos = 0;
        this.readPos = 0;
        this.modulus = 0;
        this.eof = false;
    }

    private byte[] decode(String pArray) throws Exception {
        return this.decode(getBytesUtf8(pArray));
    }

    private byte[] decode(byte[] pArray) {
        this.reset();
        if(pArray != null && pArray.length != 0) {
            this.decode(pArray, 0, pArray.length);
            this.decode(pArray, 0, -1);
            byte[] result = new byte[this.pos];
            this.readResults(result, 0, result.length);
            return result;
        } else {
            return pArray;
        }
    }

    private boolean containsAlphabetOrPad(byte[] arrayOctet) {
        if(arrayOctet == null) {
            return false;
        }
        else {
            for (byte element : arrayOctet) {
                if (61 == element || this.isInAlphabet(element)) {
                    return true;
                }
            }
            return false;
        }
    }

    private static byte[] getBytesUtf8(String string) throws Exception {
        return getBytesUnchecked(string, "UTF-8");
    }

    private static byte[] getBytesUnchecked(String string, String charsetName) throws Exception {
        return string.getBytes(charsetName);
    }

    private static String newString(byte[] bytes, String charsetName) throws Exception {
        return new String(bytes, charsetName);
    }

    private static String newStringUtf8(byte[] bytes) throws Exception {
        return newString(bytes, "UTF-8");
    }
}

Output would be as like if your user id and message id is correct:

Snippet=Hello bro how are you?Some italic mode text
Return-Path == xxx@gmail.com
From == xxx@gmail.com
Reply-To == "Reply To" <some_reply_address@gmails.com>
MIME-Version == 1.0
Date == Mon, 21 Nov 2016 00:31:53 -0500
Subject == Test email on: 21/11/2016 06:31:44
To == "To Address" <xxx@xxx.com>
Content-Type == multipart/mixed; boundary="5258f110dfc605186344f1668864cea5"
Message-Id == <CAD-od7dd=JedEjLxQPLLTMwJ93ZSpWdwZHsWD_eL-Jr1M=iWWA@mail.gmail.com>
Key=<<attachments>> == [
	{fileName=My-pdf.pdf, mimeBodyPart=javax.mail.internet.MimeBodyPart@490ab905, type=attachment, fileType=application/pdf}, 
	{fileName=My-image.png, mimeBodyPart=javax.mail.internet.MimeBodyPart@56ac3a89, type=attachment, fileType=image/png}
]
Key=<<html>> == <b>Hello bro how are you?</b><i style='color:blue;'>Some italic mode text</i>
Key=<<text>> ==